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INDUCTION OF CRANK/CAMSHAFTS PAGE 17 ACTIVE SCREEN PLASMA PAGE 24

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SEPTEMBER 2013 • VOLUME 1 • ISSUE 1 3

TABLE OF CONTENTS 10 HEAT TREAT 2013 EXHIBITOR SHOWCASE The exhibit hall at the 27th ASM Society Conference and Exposition in Indianapolis will be packed with quality company displays. A few exhibitors are highlighted. 13 ICME TOOLS CAN HELP CONTROL GEAR DISTORTION FROM HEAT TREATING Junsheng Wang, Xuming Su, Mei Li, Ronald Lucas and William Dowling 17 LOW-DISTORTION, HIGH-QUALITY INDUCTION HARDENING OF CRANKSHAFTS ABOUT THE COVER: Induction hardening of triple-lobe cast cams. Courtesy of AND CAMSHAFTS Inductoheat Inc. www.inductoheat.com. Gary Doyon, Valery Rudnev, and John Maher 20 MODELING DISTORTION EDITOR Frances Richards AND RESIDUAL STRESSES OF CONTRIBUTING EDITOR Ed Kubel AN INDUCTION HARDENED TRUCK AXLE ART DIRECTOR Barbara L. Brody Zhichao (Charlie) Li, B. Lynn Ferguson, Valentin Nemkov, Robert Goldstein, PRODUCTION MANAGER Joanne Miller John Jackowski, and Greg Fett NATIONAL SALES MANAGER 24 ACTIVE SCREEN PLASMA NITRIDING Erik Klingerman H.-J. Spies, H. Biermann, I. Burlacov, and K. Börner Materials Park, Ohio tel: 440/338-5151, ext. 5574 fax: 440/338-8542 DEPARTMENTS [email protected] 4 EDITORIAL HEAT TREATING SOCIETY 4 HEAT TREATING SOCIETY NEWS EXECUTIVE COMMITTEE 8 CHTE UPDATE Thomas E. Clements, President Terrence D. Brown, Immediate Past President Editorial Opportunities for HTPro in 2014 Roger Alan Jones, Vice President The editorial focus for HTPro in 2014 reflects some key technology areas Randall S. Barnes, Executive Director wherein opportunities exist to lower manufacturing and processing costs, re- duce energy consumption, and improve performance of heat treated compo- nents through continual research and development. HTProä is published quarterly by ASM International®, 9639 Kinsman Road, Materials Park, OH 44073; tel: 440/338- 5151; www.asminternational.org. Vol. 1, No. 1. Copyright© March Energy Conservation/Combustion Control/ Heating 2013 by ASM International®. All rights reserved. June Process Control The acceptance and publication of manuscripts in HTPro September Surface Engineering does not imply that the editors or ASM International® November Atmosphere/Vacuum Heat Treating accept, approve, or endorse the data, opinions, and con- clusions of the authors. Although manuscripts published in HTPro are intended to have archival significance, au- To contribute an article to one of these issues, please contact Frances Richards thor’s data and interpretations are frequently insufficient at [email protected]. To advertise, please contact Erik to be directly translatable to specific design, production, testing, or performance applications without independ- Klingerman at [email protected]. ent examination and verification of their applicability and suitability by professionally qualified personnel.

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New Supplement to Serve HTS Members t’s a bittersweet time for me, as I prepare to transition to my next role with the ASM Heat Treating So- ciety (HTS). That new role is Past President, and while I’m happy to turn over the reins to Roger Jones of Solar Atmospheres, I’m also sad to see my term as President come to a close. We’ve done some really great things in HTS over the past two years, and one of the most notable is

HTPRO the release of the first print issue of HTPro in Advanced Materials & Processes magazine, a copy of 4 which you are holding in your hands right now. Let me share the back history on this. After many years, Heat Treating Progress ceased publication in 2009 after the economic downturn and decisions I Industrial Heating based on what was best for the Heat Treating Society. We entered into a relationship with mag- azine to continue to provide our members with Heat Treating Society updates via the HTS Insider, and we enjoyed that partnership into 2013. Our continued focus on generating quality technical content and the de- Where is Vision 2020 in 2013? mand for print advertising with HTS, combined with an opportunity to join In 1999, the ASM Heat Treating Society Research our efforts with ASM’s Advanced Materials & Processes magazine, resulted & Development Committee created its Re- in the launch of the HTPro print publication, a quarterly supplement to search & Development Plan, an implementa- AM&P, and the hard copy cousin of our HTPro eNewsletter. By putting our- tion plan to achieve the high-priority research initiatives needed to accomplish Vision 2020 – selves in the ASM flagship print vehicle, we are expanding our audience a vision of what heat treating would look like within the ASM family and adding to the overall content growth strategy of in the year 2020. Vision 2020 describes the ASM’s position as Everything Material. changes in both the structure of the industry As I come to the end of my term as HTS President, I want to thank all the and in heat treating processes required to re- duce energy consumption, operating costs, committed men and women of our organization who devote their time and and environmental impact by the year 2020. talents to the development of their professional society. You are the heart of HTS and your efforts are appreciated. To those of you who have not volun- The 1999 R&D Plan identifies needs in three teered with HTS or ASM, I encourage you to consider doing so. Volunteer- areas: Equipment and Hardware Materials, ing makes you a better professional; it broadens your understanding of our Processes and Heat Treated Materials, and En- industry and enhances your professional and personal networks, improving ergy and Environment. In 2006, the R&D Com- mittee reviewed each area, identifying you in ways you never dreamed of. research completed or underway by industry, I look forward to seeing you at the HTS Conference and Exposition in labs, and universities that directly or partially Indianapolis. addressed various initiatives. We are now operating in a different environ- ment than we were at the last update of Vi- sion 2020. A further update to show the Thomas E. Clements progress in achieving objectives requires iden- tifying completed and ongoing research and President, Heat Treating Society emerging technologies that address Vision 2020 goals. The Committee has taken on this Heat Treating Society Announces Creation of the task with a plan to prepare and publish an ASM HTS/Surface Combustion Emerging Leader Award update on research progress, both to estab- The ASM HTS/Surface Combustion Emerging Leader Award was established in 2013 to recog- lish where we are now and to provide a nize an outstanding early-to-midcareer heat treating professional whose accomplishments ex- framework for action to drive future research hibit exceptional achievements in the heat treating industry. The award was created in activities. The information will be included in recognition of Surface Combustion’s 100-year anniversary in 2015. The award acknowledges updated initiatives and will also be shared in an individual who sets the “highest standards” for HTS participation and inspires others around several overview articles to be published by him/her to dedicate themselves to the advancement and promotion of vacuum and atmos- the ASM Heat Treating Society in the newly phere heat treating technologies. Rules for submitting nominations: launched HTPro quarterly magazine supple- • Candidates must be submitted by an ASM International member. ment. These overviews will help structure a • Nominations should clearly state the nominee’s impact on the industry and/or service and framework for action to promote future re- dedication to the future of the HTS. Three support letters should be included with the search activities to achieve Vision 2020. nomination. • Nominees must be 40 years of age or younger, and employed full time in the heat treating If you would like to contribute to this endeavor, industry for a minimum of five (5) years. you can provide information on completed and ongoing heat-treating related research at your The award shall be presented to one (1) recipient every two (2) years at the General Member- organization. Please include the project name ship Meeting at the HTS Conference and Exposition. Winner receives a plaque and $4000 cash with a brief description of objective(s), results, award funded by Surface Combustion. benefits to heat treaters, and any supporting For rules and nomination form for the ASM HTS/Surface Combustion Emerging Leader Award, visit graphics. Send your material to Ed Kubel at the Heat Treating Society Community Web site at http://hts.asminternational.org and click on Mem- [email protected]. bership & Networking and HT Awards. For additional information or to submit a nomination, con- tact Sarina Pastoric at 440/338-5151, ext. 5513, or [email protected].

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HTS Names New Board Members for 2014 The HTS Awards and Nom- inating Committee named new board members includ- HTPRO ing Steve Kowalski to serve as vice president for the 2013–2015 term; Stephen Mashl, James Oakes, and 5 Jin Xia, to serve on the HTS Jones Kowalski Mashl Oakes Xia Birt Sigelko Board for the 2013–2016 term; Aaron Birt to serve as student board member high-pressure gas , and government financ- The new for the 2013–2014 term; and Jeff Sigelko to serve as ing of business development. board will young professional board member for the 2013–2014 begin its term. Terms begin September 1, 2013. Leaving the Stephen J. Mashl is research professor at Michigan term on board are Terrence Brown (past president), Subi Technological University, Houghton, and heads Z- September 1, Dinda (member), John Keough (member), Mike Met Inc., a materials consulting company. He also 2013. Schneider (member), Benjamin Bernard (young worked for Ames Laboratory (Iowa), the U.S. Naval professional board member), and Charles Hartwig Research Laboratory (Washington, D.C.), and Body- (student board member). Thomas Clements be- cote (Mass.). Stephen is currently chairman of the comes past president, and Roger Jones becomes pres- International HIP Committee and was program ident on September 1, 2013. chair of HIP ’08. He is past president of the Ad- vanced Particulate Materials Association, past mem- Roger A. Jones is corporate president of Solar At- ber of the MPIF Board of Governors, and was mospheres Inc., Souderton, Pa. After graduating technical co-chair of PowderMet 2009. He also from Hocking Technical College, he joined ABAR served as Bodycote representative in the Center for Corp. in 1975. In 1978, he joined Vacuum Furnace Heat Treating Excellence (CHTE) at WPI. He au- HTS/Bodycote Systems Corp., founded by his father William R. thored more than 50 publications including the Student Paper Jones, FASM. In 1983, he helped found Solar Atmos- chapter on HIP of metal castings in the 2008 ASM Contest pheres Inc., serving as vice president, became presi- Metals Handbook. Mashl is an active member of Student papers are dent in 1993, and became corporate president in ASM International, the ASM Heat Treating Society, being solicited for 2001. He has been a member of the Metal Treating TMS, APMI, EPMA, and MPIF. the ASM HTS/ Bodycote Best Institute since 1983, serving on the Board of Trustees Paper in Heat (1998–2004, and 2009–present), and as president Jim Oakes is vice president of business development Treating Contest. (2004–2005). Roger has been a member of ASM for Super Systems Inc. (SSi), Cincinnati. Since join- The award is Philadelphia Liberty Bell Chapter since 1983, and ing SSi in 2005, Jim has overseen marketing, helped endowed by chapter president (1993–1994). He was chair of the develop product innovation strategies, and drives Bodycote Thermal ASM Heat Treating Society (HTS) Immediate Needs SSi’s commitment to quality and continuous im- Process-North Committee and the HTS Education Committee, provement in the company’s heat treating-related America. The winner receives a served on the Nominating Committee for two sepa- products. Prior to joining SSi, Jim worked at Oracle plaque and a check rate terms, and is a member of the HTS Technology Corp., Redwood City, Calif., helping organizations for $2500. Paper & Programming Committee. He was elected to the leverage technology to become more competitive submission HTS Board in 2005. and improve processes with enterprise software so- deadline is lutions. Jim is on the board of the Metal Treating In- December 13, Steven G. Kowalski is president of Kowalski Heat stitute and is a member of several committees 2013. To view rules Treating Co., Cleveland, assuming the position in1997 focused on bringing value back to the members. He for eligibility and paper submission, for the second-generation family business. He earned has been involved with ASM International for many visit http://hts. his B.S. degree in business administration from Miami years at the local chapter level, and contributed to asminternational. University in 1984. Kowalski is a member of the Metal the revised ASM Handbook on Heat Treating. org/portal/site/ Treating Institute and was a founding member of the hts/HTS_Awards. ASM Heat Treating Society. He served on the Heat Dr. Jin Xia is Chief Materials Engineer for The Submissions should Treating Society Board from 2003–2010, served as Timken Co., Americas, Canton, Ohio. He earned his be sent to: Sarina chair of the HTS Membership Committee from B. Eng. degree in materials science and metallurgical Pastoric, ASM Heat 2006–2013, and also served as chair of the ASM engineering from University of Chongqing, China, Treating Society, Membership Committee from 2012–2013. Kowalski in 1982; his Ph.D. in materials science and metallur- 9639 Kinsman Rd., served on many non-profit boards working to en- gical engineering from École Polytechnique de Mon- Materials Park, OH 44073; hance private and public partnerships. He has also tréal; and his MBA from Université de Paris 440/338-5151 ext. worked with local, state, and national employment or- Dauphine, France, and Université du Québec à Mon- 5513; ganizations to develop and implement training pro- tréal in 2003. Prior to joining Timken, he was an in- sarina.pastoric@ grams to enhance worker retention rates. Steve has vestigator at Analyse et Prévention de Défaillance asminternational. published several papers on furnace systems controls, Ltd. in Montreal (1989–1991); project manager and org.

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5th International metallurgical dept. manager at Exceltor Inc., Canada ence and engineering in 1999. During his undergrad- Conference on (1992–1994); and heat treat supervisor, quality man- uate years, Jeff had several papers published on lead- Thermal Process ager, and manager of engineering and new product free soldering research conducted under the Modeling and development at Torrington Co., Bedford, Mass. direction of Prof. K.N. Subramanian, including one Computer (1994–2003). He joined Timken in 2003 as chief ma- published in Advanced Materials & Processes in Simulation terials engineer for China, assuming his current po- March 2000. Jeff joined American Axle & Manufac- (co-located with sition in 2009. turing (AAM), Detroit, in 2000, working in the Cor- AeroMat)

HTPRO porate Materials Lab, and as a process metallurgist June 16–18, 2013 6 Gaylord Palms Resort Aaron M. Birt earned his B.S. degree in mechani- for induction hardening and conventional gas car- & Convention Center cal engineering at Lafayette College, Easton, Pa., in burizing in the driveline division. While at the com- Orlando, Fla. 2012, and is pursuing a M.S. degree in materials pany, he received his M.S. degree in materials science science at Worcester Polytechnic Institute (WPI), and engineering from Wayne State University, De- Abstract submission deadline is November Mass. His research involves creating a process con- troit, in 2003. Jeff currently is metallurgy leader for 11, 2013. To submit trol model for laser-assisted cold spray, and en- MSP Industries Corp. (an AAM owned company), an abstract, or for hancing the process with an in-situ heat treating Leonard, Mich. conference details, laser. He is a member of the Venture Forum and is visit www. chair of WPI’s Material Advantage Chapter. asminternational. Continuing board members include Timothy De org/modeling. Jeff Sigelko graduated from Michigan State Univer- Hennis, William Disler, Bill Flower, Robert Gold- sity, East Lansing, with a B.S. degree in materials sci- stein, Richard Howell, and Christopher Klaren. Hubbard Receives 2013 George Bodeen Heat Treating Achievement Award Mr. John D. Hubbard, CEO (retired), Bodycote plc, headquartered in Macclesfield, Cheshire, UK, is the recip- ient of the 2013 George H. Bodeen Heat Treating Achievement Award.

Established in 1996, this award recognizes distinguished and significant contributions to the field of heat treating through leadership, management, or engineering development of substantial commercial impact. Hubbard is recognized “for a lifetime of devotion to and advancement of heat treating by transforming numerous small localized commercial heat treat providers into a network of knowledgeable and techno- logically strong heat treating facilities to meet the needs of the worldwide manufacturing community.”

Hubbard worked nights at Warner & Swasey while earning a B.S. degree in metallurgical engineering at Cleveland State University. After graduating in 1970, he was appointed metallurgical engineer and promoted to manager of heat treating departments for six facilities. He received his MBA from Cleveland State in 1973 and was a part-time adjunct professor for Business Ethics and Statistics at the university. He and a partner founded Furnace Services and Furnace Controls in Cleveland in 1973, and sold the companies in 1976. He joined Hinder- liter Heat Treating Inc., North American Heat Treat- 2013 HTS/Bodycote Best Paper ing Group in 1976 as general manager, and became in Heat Treating Award president in 1983. Bodycote plc acquired the company The winner of the 2013 HTS/Bodycote Best Paper in Heat in 1996 and Hubbard became president of Bodycote’s Treating Award is entitled, “Localized Surface Modifica- North American Thermal Processing Div. In 2002, he tion on 1018 Low by Electrolytic Plasma became CEO of Bodycote plc, growing the company Process and its Impact on Corrosion Behavior,” by (pri- from ₤479m (~$745m) and 5700 employees to ₤730m mary author) Dr. Jiandong Liang, who recently received (~$1.1b)and 11,000 employees in more than 300 facil- his Ph.D. in mechanical engineering from Louisiana ities in 32 countries when he retired. State University, Baton Rouge. The award will be pre- sented at the HTS General Membership Meeting on Hubbard was on the Board of Trustees for the Metal Tuesday, September 17, at the ASM Heat Treating Soci- Winner of the Treating Institute (1983–1986 and 1994–2002), and HTS/Bodycote ety Conference and Exposition in Indianapolis. was MTI president (2000–2001). He was a founding 2013 Best member of CHTE, was on the Heat Treating Society Paper in Heat The ASM Heat Treating Society established the Best Treating Board of Directors (1994–2000) and HTS president Paper in Heat Treating Award in 1997 to recognize a Award, Dr. (2000–2001), and received the ASM Distinguished Jiandong Life Member Award in 2005. paper that represents advancement in heat treating Liang. technology, promotes heat treating in a substantial way, or represents a clear advancement in managing the business of The award will be presented at the HTS General heat treating. The award includes a plaque and $2500 cash prize en- Membership Meeting on Tuesday, September 17, at dowed by Bodycote Thermal Process-North America. the ASM Heat Treating Society Conference and Ex- position in Indianapolis.

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The Center for Heat Treating Excellence Joins Industry with Academia to Address Critical Research Needs While research and discovery are necessary Induction for innovation, not all segments of the in- CHTE collaborators are developing a funda- dustry are able to keep pace. To bridge this mental understanding of the induction tem- gap, industry leaders working together with pering process, including the effects of university researchers at Worcester Polytech- induction process parameters of power (kW) HTPRO nic Institute’s (WPI) Center for Heat Treating CHTE members often work together to and frequency (kHz) on the microstructure 8 Excellence (CHTE) are solving business chal- achieve concrete business results. As an and properties of the induction tempered lenges and improving manufacturing example, Thermatool, a producer of pipe part. A comparison of the microstructures, processes. Projects are aimed at reducing and bar harden and temper lines, asked residual stress distribution, and mechanical cycle times, increasing furnace efficiency, CHTE researchers to model applications properties (hardness, impact toughness, and of its Precision Slot Quench Ring. The ap- enhancing heat treating process control, im- torsional properties) of induction tempered plication is a critical heat treating proving surface treating processes, and in- method for the industrial bearing and with furnace tempered steels is also creasing energy savings, efficiency, and specialty steel company of CHTE mem- underway. conservation in heat treating operations. ber Timken Co. Thermatool was able to show, through the simulation modeling High Pressure Gas Quenching Since its launch in 2000, CHTE continues to and technical knowledge of CHTE, that CHTE is actively working to develop a standard provide a forum for the heat treating indus- its product could meet Timken’s needs. method (procedure and device) for evaluating try to pool its resources and engage in col- CHTE provided an avenue of communi- material hardenability for gas quenching, laborative and innovative research to cation between the companies that al- which involves slower cooling rates than are advance the industry. Members include lead- lowed them to perform trusted encountered in oil and water quenching. Re- independent analysis with everyone’s ers from both industry and academia, and searchers are also developing a standard best interests in mind, resulting in a by joining forces, CHTE created an organiza- win-win proposition for all parties. method to characterize the cooling in a given tion of unsurpassed technical expertise and gas quench system. results-oriented networking. Heat Treating Energy Use and Reduction Collaborative Research Energy costs are a major concern for the heat CHTE industry members collaborate with WPI treating industry, so collaborators use the U.S. faculty and students on research projects Department of Energy’s PHAST software to targeted at solving real-world problems by identify energy losses in a variety of furnaces selecting projects that meet their most de- and recommend methods for conservation. manding business needs. Projects focus on CHTE tested and modeled Thermatool’s precision slot quench high-priority issues including: Surface engi- ring to achieve winning results. Results-Oriented Networking neering (, nitriding, and carboni- CHTE members include leaders from com- triding); Improvements in furnace fixtures process and determine boundary conditions mercial and captive heat treaters, suppliers, and alloy service life; Cycle time reduction; for carbon and nitrogen absorption, and diffu- and manufacturers. Membership offers the Energy efficiency and savings; Nondestruc- sion coefficients of carbon and nitrogen in opportunity to network and share ideas and tive examination; Gas quenching; Induction steel during the process. knowledge on common problems and issues. tempering; Quality control; Control of distor- Industry members include: Air Liquide, Air tion and residual stress; and Solutionizing Nitriding – Fundamentals, Modeling, Products, ALD, ASM International, Bluewater, and aging of aluminum alloys. and Process Optimization Caterpillar, Chrysler, Cummins, Deformation Gas nitriding often suffers from poor perform- Control Technology, GKN Sinter Metals, A few of the Center’s recent projects include: ance reliability, limiting its application. To help Harley-Davidson, John Deere, Lawrence Liver- Nondestructive Testing achieve reliable performance, CHTE re- more National Lab, Sikorsky, Praxair, Sousa for Surface Hardness and Case Depth searchers are building an effective model to Corp., Spirol, Surface Combustion, Therma- The heat treating industry requires accurate, simulate gas nitriding of steels, based on the tool, Thermo-Calc Software, Timken Co., and rapid, and nondestructive techniques to fundamental understanding of thermodynam- others. measure the surface hardness and case depth ics and kinetics. on carburized steels for process verification Unsurpassed Technical Knowledge and control. The objective of the present study Gas and Vacuum Carburizing and Expertise is to identify, develop, and verify nondestruc- To save businesses time and money, CHTE re- CHTE is supported by WPI – one of the top en- tive techniques that overcome the limitations searchers are optimizing industrial carburiz- gineering universities in the world. The CHTE of current measurement methods. ing process parameters by developing team consists of research experts in surface effective gas and vacuum carburizing models treating, process modeling, heat and mass Carbonitriding – Fundamentals, Modeling, through a simulation program called CarbTool, transfer, solidification processing, aluminum and Process Optimization which calculates the carbon concentration alloy development, computer-aided fixture de- CHTE collaborators are working to model the profile during the processes. sign, and degradation phenomena. “CHTE makes it easy to tap into a pipeline of invaluable knowledge and a far-reaching network of excellent people with countless years of heat treating experience.” Alexander Brune, Sikorsky Aircraft

For more information about CHTE and its member services, visit www.wpi.edu/+chte.

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Can-Eng Furnaces International Ltd. Established in 1964, CAN-ENG Furnaces International Limited is a leading designer and manufacturer of thermal processing equip- ment for ferrous and non-ferrous metals. Whether manufacturing a simple, manually con- trolled furnace or a turnkey automated system, CAN-ENG focuses on the development HTPRO 2013 of high volume batch and 10 continuous industrial fur- naces for challenging appli- EXHIBITOR SHOWCASE cations. CAN-ENG leads improvements and changes The exhibit hall at the 27th ASM Heat Treating Society in the industry with its Re- search and Development Conference and Exposition in Indianapolis will programs. Its R&D has three be packed with quality company displays. areas of focus: developing new technology, developing new A few key exhibitors are highlighted here. Visit them on processes and improving and optimizing existing technology. CAN- ENG’s strength is the ability to custom engineer a furnace for any September 17 (9:00 a.m. – 6 00 p.m.) and 18 customer requirement. CAN-ENG is an ISO 9001:2008 certified com- (9 a.m. – 5:00 p.m.) at the Indiana Convention Center. pany. www.can-eng.com Be sure to attend the Networking Reception Booth 1817 5:00 p.m. – 6: 00 p.m. on Tuesday night.

AFC-Holcroft Dry Coolers Inc. Offering thermal processing solutions to meet the increasing de- Solanus Quench Oil Cooler mand for flexible, scalable heat treatment systems with consistent, Dry Coolers of Oxford, Michigan, leads the heat treat industry repeatable metallurgical results. with the design of fluid cooling systems. Dry Coolers is introduc- Our featured UBQ (Universal Batch Quench) sys- ing its new global tem is capable of running a variety of metallurgi- standard Solanus cal processes; whether a single unit or as a Quench Oil Cooler. complete, fully-automated cell integrated with The Solanus features companion equipment. With its compact, modu- include removable cover- lar design, additional cells can be added for max- plates for ease of clean- imum production flexibility. ing, direct drive low-noise When high volume production is needed, our fans, and non-plugging classic pusher-style furnace offers continuous large diameter finned throughput under protective gas atmosphere. Many of tubes. Dry Coolers manu- the largest manufacturers worldwide rely exclusively on AFC-Hol- factures and designs croft pusher furnaces for maxi- cooling systems for vac- mum control and economy. uum furnaces, atmosphere furnaces, induc- With offices on 3 continents tion systems, and salt baths. Whether an and partners worldwide, AFC-Hol- air-cooled, evaporative, or chilled fluid cooling croft stands ready to help you meet your specific heat treatment system is needed, Dry Coolers has the coolest solution! needs. ISO 9001:2008 certified. www.AFC-Holcroft.com www.drycoolers.com Booth 1723 Booth 1710

BeaverMatic Inc. GeoCorp Inc. Jack Beavers began a determined journey toward furnace inno- GeoCorp Inc. is a manufacturer of thermocouples and thermo- vation with simplified yet sophisticated equipment designs 50 couple wire. GeoCorp keeps an extensive inventory so thermocou- years ago. From our past successes and solid installation base, ple and thermocouple wire lead-times are DAYS NOT WEEKS to ship. BeaverMatic remains steadfastly focused We can even inventory your products at our plant through our blan- on its core competency to build simplified ket order system so the product is ready to ship the same day. All yet dependable performance-proven thermocouples and thermocouple wire meets Boeing BAC 5621 K, equipment. Today, BeaverMatic is a AMS 2750 Rev.E, CQI-9 and P10TF3 requirements. GeoCorp can offer family-owned manufacturer of custom, thermocouples and thermocouple wire with a maximum tempera- standard, batch and continuous ture tolerance of +/- 2°F or 0.2%, whichever is greater. We have an atmosphere heat-treating equipment. on-site ISO 17025:2005 accredited calibration lab that provides tem- Best known for the Internal Quench perature certification for thermocouples and thermocouple wire. Furnace with Beaver Ram transfer www.geocorpinc.com system, BeaverMatic’s product line includes temper furnaces, washers, endothermic gas generators, box furnaces, pit furnaces, continuous pushers, carbottom furnaces, and tip up furnaces. Come visit us in booth 2016 where we will feature the various Internal Quench Furnace configurations that we have avail- able. www.beavermatic.com Booth 2016 Booth 1706

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Induction Tooling Inc. Kureha America Inc. Induction Tooling Inc. has received ISO/IEC 17025 Accreditation for Kureha has the solution for you! Specializing in carbon and Mechanical Testing. Since our core business is the design, fabrica- graphite fiber products, whether you need stock boards or custom

tion and repair of heat treat inductors machined parts for your high temperature applications, Kureha can HTPRO and associated tooling, it made handle it. With production sites located in Japan, China, and the sense to integrate our induction and U.S., Kureha Carbon Products Division has the capacity and variety metallurgical laboratories. The in- of products to meet your carbon and graphite fiber needs. Our duction laboratory is a valuable ex- Kreca Felt, Kreca RGS, or Kreca FR materials will be the right choice tension of our services, allowing us to insure your heat stays where it should. Contact us today. the ability to not only design and www.kureha.com. fabricate high quality inductors, but 11 also characterize them on-site. The Metallurgical Laboratory will record process parameters for production and formally validate the results in a format that can be submitted directly to the end customer. We recognize a significant reduction in the time required to get inductors from design and into production. Ad- ditionally, ITI will provide testing services to the general heat treat- ing industry. www.inductiontooling.com

Booth 1728 Booth 1744

Inductoheat Inc. Surface Combustion Inc. Inductoheat Inc. will again be attending the ASM Heat Treating Diverse Thermal-Processing Equipment Society Conference and Exposition September 16th through 18th. We Surface Combustion has ex- encourage everyone to take advantage of this opportunity to view celled at applying original tech- our latest advancements in technology. Inducto- nology and broad thermal processing abilities to new and heat Inc. will be located at booth #1701 and our Team is looking for- unique material processing chal- ward to walking you through our exhibit and introducing you to our lenges since 1915. new IFP (Independent Frequency & Power) power supply. Whether it’s enhancing past or For more information about our induction heating, heat treating and existing technologies to the latest forging equipment, please visit our website, www.Inductoheat.com. requirements, or innovating new and exciting technologies through extensive research efforts, Surface continues to work with our cus- tomers in providing them the best in high performing and reliable equipment to meet all of their needs. Our designs address a diverse

® field of applications with high-tech automated furnace lines,including batch, continuous, vacuum carburizing and vacuum tempering equipment. www.surfacecombustion.com Booth 1701 Booth 1601

Ipsen Inc. United Process Controls How will you build yours? United Process Controls provides process control, flow control, Ipsen believes that innovation drives excellence, and we defi- and automation solutions to furnace OEMs and customers with nitely believe that such excellence should be rewarded. So show thermal processing equipment and operations. Products range from Ipsen your innovative excellence and visit Ipsen’s booth, #1529, to probes, analyzers, flow meters, programmable controllers, gener- build your paper airplane for a chance to win an iPad and other ator and gas mixing control systems, SCADA to complete turnkey great prizes. Chat with Ipsen experts systems. while you construct your aerody- The company is comprised of four brands - Furnace Control Corp, namic masterpiece. Marathon Monitors, Process-Electronic, and Waukee Engineering. But the innovation doesn’t have to www.unitedprocesscontrols.com stop there! Share your heat treating story with Ipsen and find out how you can con- struct your dream facility and get the process results you want most with our dependable and durable Ipsen technology. Our ded- icated research and development team - Team Innovation - is con- stantly pushing the boundary of possibilities and dreaming of a future of thermal processing excellence. So come show us what you’ve got and we’ll show you what we’ve got! www.IpsenUSA.com Booth 1529 Booth 1823

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ICME TOOLS CAN HELP CONTROL

GEAR DISTORTION FROM HEAT TREATING HTPRO INTEGRATED COMPUTATIONAL MATERIALS ENGINEERING TOOLS ENABLE ACCURATE SIMULATION OF GEAR HEAT TREATMENT TO PREDICT PHASE TRANSFORMATION KINETICS AND DISTORTION. Junsheng Wang, Xuming Su, and Mei Li 13 Ford Research and Advanced Engineering Lab, Ford Motor Co., Dearborn, Mich. Ronald Lucas and William Dowling* Powertrain Manufacturing Engineering, Ford Motor Co., Livonia, Mich.

Most gears used in industrial applications ciency has led to weight reduction of eral boost intervals, because its decom- are carburized and quenched to meet transmission components, and trans- position is catalyzed by iron atoms at the surface and core hardness and overall mission gears of thinner cross section gear surface, providing high carbon po- fatigue strength requirements. Low are more sensitive to distortion during tentials for diffusion into the austenitic pressure vacuum carburizing (LPC) com- manufacture[1-2]. Transmission gears structure[5]. After achieving the desired bined with high pressure gas quench- have very tight dimensional tolerances 0.3–1.0 mm carburized case depth, the ing (HPGQ) offers the opportunity to to meet durability, as well as noise, workload is transported into the minimize environmental impact, elimi- vibration, and harshness (NVH) quenching chamber where controlled nate oxidation and surface decarburiza- requirements. This creates processing cooling using high pressure, turbulent tion, accurately control case depth and challenges from machining through nitrogen gas flow produces the desired core hardness, and produce consistent heat treating. Along with the effects of microstructure[6]. Surface and core hard- microstructure, and thus, fatigue per- residual stresses from machining, dis- ness, as well as properties such as fatigue formance from batch to batch. tortion is caused by nonuniform plas- strength, wear resistance, and pitting LPC/HPGQ has the potential to mini- tic deformation due to thermal and corrosion resistance are determined by mize distortion by controlling such pa- phase-transformation stresses during the microstructural constituents result- rameters as gas flow velocity, operating heat treatment. Parts that do not meet ing from different cooling rates and car- pressure, chamber geometry, and fixture quality control specifications may re- bon profile[6]. materials. A time-efficient, cost-effective quire additional grinding and other way to optimize those parameters is to corrective measures to meet dimen- For example, a straight quench at con- integrate various computational tools sional tolerances, which significantly stant pressure and velocity leads to a such as computational fluid dynamics increases costs. large temperature difference between (CFD), finite element analysis (FEA), and the gear surface and core, introducing microstructure modeling to perform nu- Low pressure carburizing combined nonuniform thermal and - merical tests for specific type of gears. with high pressure gas quenching pro- transformation stresses, which can This article discusses the development of duces less distortion compared with cause distortion as shown in Fig. 1b. an integrated computational materials other heat treating methods[3-4]. It con- Stop quench, dynamic quenching, and engineering (ICME) tool and its practical sists of vacuum carburization at an reversing quenching are recent develop- application in product development. austenitizing temperature of ~930°C fol- ments[1-5] used to control cooling rate lowed by high pressure nitrogen gas (and thus phase transformation) in three Manufacturing challenges quenching at 1–20 bar (Fig. 1a). Acety- steps: (1) high quench severity prior to Increasing demand for vehicle fuel effi- lene is supplied at low pressure in sev- martensite phase transformation to *Member of ASM International

(a) (b) (c) Straight quench Step quench ~930°C, low pressure <20 mbar High pressure P, v = constant P, v ¹ constant 1–20 bar Austenite ~870°C Tcore T C2H2 ® 2C + H2 Pearlite core Pearlite Pearlite Carburizing Diffusion ~400°C Bainite

N2 + acetylene M s DT Bainite Tsurf. Bainite boost N2 flow Temperature Temperature Temperature Ms Ms N2 flow Heating Quenching Tsurface DT » 0 27°C Time Time Time Fig. 1 — (a) LPC and HPGQ heat treating process and schematics of (b) straight quench and (c) step quench.

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[12] Carburizing temperature vs. time during quenching . However, com- Martensite Carbon potential vs. time Mechanical properties: mercial CFD codes are intrinsically un- Nucleation & distribution sf (phase, T, e…) able to accurately predict the thermal Carbon Carbon growth kinetics: content V (phase, C,…) E (phase, C,…) history of the gear quenching process diffusion 0 CTE (phase, C,…) analysis a (phase, C,…) due to the lack of a phase-transforma- b (phase, C,…) etransformation (phase) C (x, y, z) tion model. We implemented a subrou- c (phase, C,…) C(x, y, z, t), T(x, y, z, t) tine in the commercial Fluent CFD code CFD C(x, y, z, t) Phase transfor- Mechanical

HTPRO to take the latent heat effect due to analysis T(x, y, z, t) mat ion analysis f i analysis 14 phase transformation into account. r(phase, C, T) Thermodynamics: M (C,…) CP (phase, C, T) s Model validation is accomplished using l(phase, C, T) TTT (C,…) experimentally measured temperature nN2 (T) Temperature Hardness L(dT(x, y, z)/dt) distribution Displacement ´100 distribution data (Fig. 3 I-a) at 40 and 100% fan Fig. 2 — ICME-GearHT is a suite of integrated computational materials engineering (ICME) speeds. Figure 3 I-b shows that higher tools to predict quantitative processing-structure-property relationships for gear heat cooling velocity results in higher heat- treatment. transfer coefficient. The predicted ther- avoid pearlite formation, (2) tempera- carbon potentials and diffusivities meas- mal profile captures the effect of latent ture equalization in each part, and (3) ured from experiments. The Abaqus heat release, agreeing well with experi- fast cooling to generate martensite for (Dassault Systèmes) FEA model calcu- ments for different gear orientations (Fig. surface and core hardening (Fig. 1c). lates the kinetic process of carbon diffus- 3 I-c). Temperature uniformity during ing into austenitic interstitial sites, which HPGQ is critical for improving process The prediction of heat transfer in com- expands the lattice, and introduces a car- performance to minimize distortion and bination with the phase-transformation bon gradient into the gear. The resulting maximize gear service life. Therefore, the process during HPGQ has become in- nodal carbon concentrations serve as ICME-GearHT model was used to eval- creasingly important as more attention input to the subsequent high pressure- uate properties of furnace-fixture mate- is paid to optimizing the quenching gas quench analysis. Transient heat trans- rials, chamber configurations, and parts process to minimize distortion[8-10]. The fer is calculated using the Fluent (Ansys loading in the furnace. need for CAE tools that can predict the Inc.) CFD model, in which the latent heat conjugate heat transfer during high of phase transformation is implemented Experimental validations pressure gas quenching and couple it as a subroutine. Carbon concentration New kinetic parameters were developed with phase transformation distortion (from FEA) and temperature values for 5130 alloy steel, which is widely used analysis led to the development of (from CFD) are fed into the DANTE (De- for transmission gears. Kinetic parame- ICME-GearHT. formation Control Technology Inc.) mi- ters in the phase transformation models crostructure model. Finally, the coupled were determined using an optimization Computational tool development Abaqus CAE and DANTE database per- approach that matches model predictions The ICME-GearHT tool enables accu- forms structural analysis for mechanical with experimental measurements. The rate simulation of the transmission gear properties of each phase. As shown ex- parameters were implemented into the heat-treatment process, predicts phase perimentally by previous authors[1-4], sur- DANTE materials database, allowing ac- transformation kinetics and distortion, face carbon concentration has little effect curate prediction of phase transforma- and provides cost-effective, time-effi- on gear distortion. Temperature and tion and seamless integration with the cient evaluation of new equipment de- phase evolution at different locations/ori- micromechanical model for calculating signs. These will ensure high quality entations control thermally and transfor- both thermal and transformation plastic- product launch and help achieve a “first- mation-induced plasticity. ity during the gear quenching process. time-through” manufacturing vision (Fig. 2). This was accomplished by gain- Model validation Distortion analysis using ICME-GearHT ing a clear understanding of the funda- The following example case illustrates is validated by mapping the distortion at mentals of carburizing, conjugate heat thermal model validation and compares various locations of the load and at three transfer, phase transformation, and mi- predicted and experimental results. Be- different quenching conditions including cromechanics during the gear heat cause different cooling rates result in step quench, 40% fan speed, and 100% treatment process; and integration with different volume fractions of martensite, fan speed. The experimental setup is the most advanced models in different nonuniform cooling rate on a single gear shown in Fig. 3 II-a. Experimentally disciplines[8-10] and related leading in- results in nonuniform distribution of measured distortion at three different dustrial experimental validations. martensite in the gear (Fig. 2). Marten- conditions (Fig. 3 II-b) agrees well with site transformation causes a 2–5% vol- previous studies[7]. Step quenching pro- ICME-GearHT analysis is broken down ume increase[11] depending on the duces less distortion and better product into four parts: carburization, CFD, composition and releases about 3.1 ×108 quality. Distortion calculations deter- phase transformation, and mechanical J/m3 latent heat[12], which complicates mined using the ICME-GearHT ap- analysis. Figure 2 shows the data require- the temperature profile of each gear. proach are compared with experimental ments and how the analyses are coupled. Therefore, it is important to include results to provide efficient, effective solu- Each analysis starts from diffusion-based transformation kinetics in modeling the tions for process design and optimiza- carburization at high temperature using transient temperature history of gears tion. Figure 3 II-c shows predicted gear

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(l-b) Fig. 3 — (I-a) 1800 1000 (l-c) (I-a) experimental setup for measuring 100% fan speed 800 K 1400 the temperature field, 2 40% fan speed 600 (I-b) heat transfer 1000 coefficients HTPRO calculated from 600 400 TC #08 experiments, HTC, W/m 200

Temperature°C Temperature°C (I-c) predicted 200 TC #09 TC #07 temperature 0 compared with 0 1 2 3 4 5 6 7 89 0 10 20 30 40 50 60 Time, s experimental results, 15 500 (lI-b) 700 (II-a) experimental After straight After 100% 400 600 setup for distortion (II-a) quench at straight fan analysis, Max 40% fan quench 500 speed, speed at 100% (II-b) distribution of 300 fan speed 400 straight quench measured distortion Min 300 values, and (II-c) 200 After stop 200 Circularity from major (Sim.) predicted distortion Circularity Before Gear #07 quench for 100% straight heat 100 Circularity from major (Expt.) Exaggerated 100 treatment distortion ´100 quench 0 (exaggerated/ 6 7 8 9 10 0 Gear Number magnified by 100´). (lI-c)

circularity, replicating the influence of have shown that use of carbon-fiber the load and within individual gears with gear location on distortion and matching composite (CFC) fixtures reduces dis- the same load volume as in a steel bas- experimental measurements in locations tortion by 25%, and by 50% by combin- ket. An improvement of 20–25% in tem- 8 and 9. Results show the model can be ing CFC fixtures with a step quench. perature uniformity is possible using used to optimize production processes Computations were performed using CFC fixtures. Evaluation of modifica- and identify the best heat-treatment both alloy and CFC fixtures to quantita- tions to the quenching system using recipe for minimized distortion. tively evaluate the benefits of new fix- ICME-GearHT shows that a proposed ture materials. CFC fixtures significantly new cooling fan and stator design along Recent experimental studies by others[1-4] improve temperature uniformity within with velocity filtering improves temper-

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ature uniformity prior to martensite tended to any case-hardening process Treat Process and Alloy on the Surface Mi- transformation by more than 20%. such as induction hardening, oil quench- crostructure and Fatigue Strength of Carbur- ing, and molten salt quench[8-10]. HTPRO ized Alloy Steel, SAE Tech. Paper Summary 1999-01-0600, 1999. 7. A. Goldsteinas, High Pressure Gas The ICME-GearHT model incorporat- Acknowledgement: The authors ac- Quench Technologies: Distortion Control & ing latent heat release due to phase knowledge the support of Dr. Zhi-Chao Mechanical Properties Improvement, SAE transformation was validated using ex- (Charlie) Li at Deformation Control Tech- Tech. Paper 2008-01-0433, 2008. nology Inc. and Dr. Ibrahim Yavuz at 8. W.E. Dowling, et al., Development of a

HTPRO perimental data. The entire workload is ANSYS Inc. Carburizing and Quenching Simulation 16 a complex thermal body subjected to large temperature variations during Tool: Program Overview, Proc., 2nd Intl. References Conf. on Quenching and Control of Distor- quenching. ICME-GearHT captures tion, ASM Intl., 1996. those variations. It was used to investi- 1. V. Heuer, et al., Low distortion heat treat- ment of transmission components, Gear 9. B. Ferguson and W.E. Dowling, Predictive gate and validate a new gas quenching Tech., Oct., 2011. Model and Methodology for Heat Treat- process, propose cost-effective, time-ef- 2. V. Heuer, et al., Distortion Control of ment Distortion, Natl. Ctr. for Mfg. Sci. Re- ficient recommendations for new trans- Transmission Components by Optimized port #0383RE97, 1997. mission-product development, and High Pressure Gas Quenching, J. Matls. 10. B. Ferguson, Z. Li, and A. Freborg, Mod- accelerate new process development. It Engrg. & Perf., 22, p 1833–1838, 2013. eling Heat Treatment of Steel Parts, Comput. Matl. Sci., 34, p 274–281, 2005. was also used to evaluate the benefits of 3. Q. Ming, et al., Uniform Quenching Tech- nology by Using Controlled High Pressure 11. R.H. Leal, Transformation toughening of using different heat treating furnace-fix- Gas after Low Pressure Carburizing, SAE metastable austenitic steels, Ph.D. thesis, ture materials and different quenching Tech. Paper 2008-01-0365, 2008, MIT, Cambridge, Mass., 1984. furnace stator and fan designs to im- doi:10.4271/2008-01-0365. 12. S.J. Lee and Y.K. Lee, Finite element sim- prove temperature distribution unifor- 4. K. Löser, V. Heuer, and D.R. Faron, Distor- ulation of quench distortion in a low-alloy mity for reduced distortion. tion control by innovative heat treating, Gear steel incorporating transformation kinetics, Tech., 8, p 54–57, 2008. Acta Mater., 56, p 1482–1490, 2008. Fundamental and experimental methods 5. Z. Li, et al., Modeling the Effect of Carbur- ization and Quenching on the Development For more information: Junsheng Wang is developed using ICME-GearHT can be of Residual Stresses and Bending Fatigue Re- research scientist, Ford Research and Ad- extended to any high pressure gas sistance of Steel Gears, J. Matls. Engrg. & vanced Engineering Lab, 2101 Village Rd., quenching process such as sun-gear and Perf., 22, p 664–672, 2013. Ford Motor Co., Dearborn, MI 48124, pinion-gear heat treatments. It can be ex- 6. W.E. Dowling, et al., The Influence of Heat 313/390-5503, [email protected].

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LOW-DISTORTION, HIGH-QUALITY

INDUCTION HARDENING HTPRO OF CRANKSHAFTS AND CAMSHAFTS REDUCING THE AMOUNT OF HEAT GENERATED WITHIN A PART 17 AND PROVIDING UNIFORM HEATING WITHOUT APPLYING FORCE GO A LONG WAY IN CONTROLLING PART DISTORTION DURING INDUCTION HARDENING. Gary Doyon*, Valery Rudnev, FASM*, and John Maher* Inductoheat Inc., Madison Heights, Mich.

Crankshafts, typically made of plain- and low-alloy medium carbon steels (e.g., SAE 1039M, 1042, 1538M), consist of a series of crankpins (also called pin jour- nals or pins) and main journals (mains) interconnected by crank counterweights. Journal diameters on crankshafts used in automobiles, tractors, and other vehicles range from 35 to 60 mm. Several induc- tion hardening methods are used to sur- in centers during heating and quench- face harden crankshaft features such as ing. The complex crankshaft geometry pins, mains, and oil seals, providing hard- lacks symmetry, in particular around pin ness in the range of 52 to 56 HRC after journals (pin axes are offset radially from hardening and tempering. Hardened case the main axis). Therefore, pins orbit the depth typically ranges from 0.75 to 2 mm main axis during rotation. The circular after grinding. orbital motion of a massive induction heating and quenching system (often ex- Depending on crankshaft design and ceeding 900 kg including a set of water- process requirements, crankshaft jour- cooled inductors, buswork, cables, etc.) nals are induction hardened using either must be precisely maintained using a band hardening or band-and-fillet hard- special control tracking system. Such ening (often simply referred to as fillet systems provide time-dependent power hardening). Band hardening is used to modulation for each heated journal dur- harden only the bearing surfaces. The ing its rotation, depending on specific hardness pattern typically ends about 0.5 counterweight geometry and the pres- to 1.5 mm from the journal fillet. Figure ence of oil holes. 1 shows induction band hardening pat- terns on etched crankshaft journals for U-shaped inductors inherently produce a V-8 automobile engine. Roll hardening a nonsymmetrical heating pattern at any is applied after induction band harden- given time, because heat is only applied ing to induce useful compressive resid- to less than half of the crankshaft jour- ual stresses in the fillet area. Band nal. The rest of the pin/main undergoes Fig. 1 — Induction band hardening patterns hardening results in smaller distortion, a soaking-cooling cycle. Nonsymmetri- on etched crankshaft journals for a which reduces the amount of grinding cal heating requires relatively prolonged V-8 automobile engine. stock required. heating times (8 to 20 s), which, in turn, heats an appreciable mass of metal, re- Induction hardening sulting in greater shape distortion and using the rotational process causing nonuniform hardness profiles From the 1960s to 2000, most induction around the perimeter. In addition, U- crankshaft-hardening machines used shaped inductors are fabricated either by non-encircling U-shaped inductors, banding or brazing copper in the shape which physically ride on the journal of a figure eight containing multiple using carbide guides (also called locators bands/joints (Fig. 2, top). Both coil fabri- or spacers), while the crankshaft rotates cation methods raise concerns about the *Member of ASM International and ASM Heat Treating Society

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precision and repeatability of complex tion coil. Crankshaft journals are heat coil geometry construction, which re- treated sequentially resting on V-blocks. quires extensive process validation after No axial force is applied. a new set of inductors is installed. SHarP-C technology dramatically Induction hardening reduces distortion and offers simple using a nonrotational process operation, equipment reliability and

HTPRO The development of nonrotational in- maintainability, and a substantial re- 18 duction hardening technology was an duction in life cycle cost. advancement in the induction hardening of crankshafts. The patented SHarP-C Inductors are CNC machined from a (Stationary Hardening Process for solid copper block; eliminating brazed Crankshafts) technology was introduced and banded components makes them ro- in early 2000, and continual improve- bust, rigid, and repeatable. This reduces ments established it as a proven process the possibility of inductor distortion dur- that eliminates the need to rotate the ing fabrication, thereby eliminating the crankshaft during heating and quench- associated hardness pattern drift. ing cycles. Millions of crankshafts have been heat treated using SHarP-C since Shape and size distortion and total indi- its introduction. cated runout (TIR) are very important parameters of the crankshaft hardening The inductor for the nonrotational hard- process. TIR directly affects the amount ening process consists of two sections of metal required to be ground off after (Fig. 2, bottom) machined from a copper hardening. One of the most important block: a top (passive) inductor and bot- factors that impacts crankshaft distortion tom (active) inductor. The is the amount of heat generated within bottom inductor is the crankshaft body. The greater the mass connected to a medium-fre- of metal heated, the greater the thermal quency power supply, expansion, which, in turn, causes greater and the top inductor distortion of components with complex, represents (electri- nonsymmetrical geometry. cally) a short circuit (closed loop). The bot- Nonrotational technology also shortens tom coil is stationary, while heating time by an average of 3 to 4 fold the top coil can be opened and closed. compared with that for the rotational Fig. 2 — U-shaped inductors are fabricated Each inductor has two semi-circular process, which reduces the mass of either by banding or brazing copper in the shape of a figure eight containing multiple areas to locate journals to be heat metal heated. Journal cores remain rela- bands/joints (top); the inductor for treated, while the top inductor is in the tively cold during the entire heating nonrotational hardening consists of two “open” position. cycle, serving as a shape stabilizer and sections machined from a copper block (bottom). practically eliminating shape distortion. A robot loads the crankshaft into the A smaller heat-affected zone (HAZ) also heating position, the top coil pivots reduces thermal expansion. into a “closed” position, and power is applied to the bottom coil. Electrical Rotational hardening applies appreciable current flows in the bottom coil, and axial force on the crankshaft to rotate it with a lamination pack that serves as during hardening, which results in resid- a magnetic flux coupler, both top and ual stress in the crank. By comparison, bottom coils are tightly electromag- the SHarP-C process places no axial netically coupled. Current flowing in forces on the crankshaft as it rests in V- the bottom coil instantly induces blocks during hardening, thereby mini- eddy currents that begin to flow in mizing stresses in the shaft. Lateral the top coil. According to Faraday’s growth is minimized and distortion and law of electromagnetic induction, TIR typically does not exceed 25 microns. the induced currents are oriented in a direction opposite that of the Hardening camshafts source current, similar to a trans- Camshafts consist of several sets of cam Fig. 3 — Cam lobe shape varies depending former effect. lobes and bearings. Cam lobe shape on engine design. varies depending on engine design as The heated crankshaft journal “sees” the shown in Fig. 3. Depending on camshaft nonrotational inductor as a fully encir- geometry and production requirements, cling, highly electrically efficient induc- shafts may be induction hardened using

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scan or static (single shot) heating of one and shape and having the same or very or more lobes, which can be rotated or similar axial gaps between them. In this motionless during heat treating. scenario, deeper case depth typically oc- curs in the nose compared with the base Scan inductors offer the greatest flexibil- circle (the heel). The cam-lobe nose has HTPRO ity by enabling lobes of various lengths to a closer electromagnetic coupling with Fig. 4 — True contour hardening of be heat treated using minimum power, the inside diameter of the copper coil. camshaft lobes use inductors that provide because only a portion of the lobe is This is one of the main causes of deeper uniform coil-to-lobe gaps and short heat times. heated. Low production rates, due to sin- case depth in the lobe nose area com- 19 gle-lobe processing, are the main limita- pared with its base circle region, leading ening profiles, dramatically minimizing tion of using a scanning technique to to camshaft distortion. distortion, and potentially eliminating surface harden automotive camshafts. the need for post-hardening camshaft Trying to produce the required range of Short heating times, the ability to develop straightening. HTPRO “minimum-maximum” hardness case a uniform austenitized layer, and process- depths is also a challenge. In addition, ing camshafts horizontally without apply- Bibliography heating lobes that have an appreciably ing any pressure during heat treating are • G. Doyon, V. Rudnev, and J. Maher, Induc- different ratio of cam-nose diameter-to- factors that contribute to a reduction in tion hardening of crankshafts and camshafts, base-circle diameter is difficult unless camshaft distortion. Low distortion can ASM Handbook, Vol 4C: Induction Heating lobes are stationary during processing potentially eliminate the camshaft and Heat Treating, ASM Intl., Materials Park, Ohio, 2014 (to be published). and properly oriented with respect to the straightening operation and reduce the al- • G. Doyon, et al., Taking the crank out of profiled inductor. Scan hardening is also lowance for grinding stock. Figure 4 illus- crankshaft hardening, Industrial Heating, p difficult when lobes are in close proxim- trates true contour hardening of camshaft 41-44, December, 2008. ity to each other (i.e., triple-lobe cams). lobes using inductors that provide uniform • V. Rudnev, et al., Induction Heating Hand- coil-to-lobe gaps and short heat times. book, Marcel Dekker, N.Y., 2003. In contrast to scan hardening, static, or For more information: single-shot, heating of multiple lobes is The nonrotational SHarP-C technology Dr.Valery Rudnev, FASM, is Director, Science and Technology, commonly used when surface hardening developed for crankshafts can easily be Inductoheat Inc., an Inductotherm Group small and medium size automotive applied for low-distortion camshaft Co., 32251 N. Avis Dr., Madison Heights, MI camshafts with lobes of the same size hardening, providing true contour-hard- 48071, 248/629-5055, rudnev@inductoheat.

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MODELING DISTORTION AND RESIDUAL STRESSES OF

HTPRO AN INDUCTION HARDENED TRUCK AXLE 20 ELECTROMAGNETIC AND THERMAL-STRESS MODELING OF INDUCTION SCAN HARDENING HOLD PROMISE FOR OPTIMIZING PART DESIGN, PREVENTING IN-PROCESS FAILURE, AND PREDICTING SERVICE PROPERTIES. Zhichao (Charlie) Li* Changes in thermal distribution stresses, which are further used to ana- B. Lynn Ferguson, FASM* throughout an induction hardening lyze the mode and location of fatigue DANTE Software, Cleveland process create complicated phase trans- failures[2]. Component geometry and Valentin Nemkov*, Robert Goldstein*, formations and stress evolutions in the process can also be optimized to reduce and John Jackowski component. Both residual stresses and part weight, trim manufacturing costs, Fluxtrol Inc., Auburn Hills, Mich. mechanical properties of the hardened and improve performance. Greg Fett* pattern have a significant impact on Dana Corp., Maumee, Ohio service performance of the heat treated Induction hardening of steel compo- parts. Induction hardening of steel com- nents is a common processing method ponents is a highly nonlinear transient due to fast heating times, high efficiency, process, and understanding the changes and ability to heat locally. However, pre- dicting final properties of a hardened component adds another layer of com- plexity. Temperature and structure must be considered, as well as electromagnet- ism. When hardening steel, magnetic properties change throughout the process, affecting thermal distribution and structure. Coupling these phenom- ena to achieve end properties after treat- ment is a state-of-the-art technology. In a simple case, stress and distortion mod- eling of ID and OD hardening of a tubu- lar product was investigated[3]. To study a component common in industry with a Fig. 1 — Geometry of the full-float truck axle. more complex geometry and subjected

(a) (b) to external stresses in service, a full-float truck axle with dimensions typical to those manufactured by Dana Corp. was selected. Using an axle (a common auto- motive component) enables comparing simulation results to desired axle prop- erties. Results are compared to typical performance criteria for the selected axle. The goal is to produce results rep- resentative of actual part performance.

Part geometry and model for thermal/stress analysis Fig. 2 — Power distribution predicted in stress state due to hardening is not in- by Flux2D (a) and temperature predicted Axles must be surface hardened for by DANTE (b). tuitive. Electromagnetic and thermal durability to prevent failure in service. stress analyses of induction hardening Hardening is commonly performed have matured with the development of using induction scanning. Induced FEA modeling capability, and they are stresses and distortion are affected by applied to understand and solve indus- the method in which the induction scan trial problems[1]. FEA is used to predict process is performed. Bowing distortion mechanical properties and residual and change in length are the main con- *Member of ASM International and ASM Heat Treating Society

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cerns during induction hardening of starts with static heating of the Flux2D FEA software. Figure 2a shows a truck axles with shafts more than 1 m flange/fillet for 9 s followed by scanning finite element meshing used to model long. Bowing distortion can be mini- with a 15 mm/s inductor travel speed. the axle by Flux2D, with a schematic mized by proper inductor design, Scan speed is decreased to 8 mm/s after temperature distribution focusing on process control, and structural support 1.5 s and remains at this speed. Power is flange and fillet regions. The axle mate- HTPRO mechanisms. Excessive heating of the turned off after an additional 119.65 s, rial is magnetic, and power density dis- shaft core is the main contributor to dis- just before the shaft end is austenitized. tribution varies greatly as the tortion, which can be evaluated by sim- Spraying continues after power is turned temperature exceeds the Curie point. In- ulation. Change in length is affected by off to complete transformation of the ductor frequency is 10 kHz, the com- 21 both shaft heating and cooling rates, a austenitized section of the shaft to mon operating frequency of Dana’s nonlinear process. The shaft studied martensite. induction machines for this class of here is a full-float truck axle made of parts. Different finite element meshes AISI 1541 from Dana Corp. A simplified Inductor design are used for Flux2D and DANTE models CAD model is shown in Fig. 1. Shaft di- and power density modeling due to different physics and accuracy mensions: 34.93 mm diameter, 1008 mm It is critical not only to meet the hard- requirements. long, 9.52 mm fillet radius between ened depth requirement, but also to pre- flange and shaft, flange diameter and vent excessive heating in regions such as A 3D finite element mesh of a single thickness are 16.5 mm and 104.5 mm, the flange, core, and shaft end. Too spline tooth is used in the DANTE soft- respectively. The spline has 35 teeth; a much heat in these regions increases the ware for thermal, phase-transformation, single tooth sector with cyclic symmet- possibility of cracking, and can lead to and stress analyses. Fine surface ele- ric boundary condition is modeled in excessive distortion. The minimum case ments are used to effectively model the this study. depth requirement for this axle shaft is thermal and stress gradients near the 5.4 mm, and case depth is defined by a surface. Power densities in the axle pre- Heat treating process hardness of 40 HRC. dicted by Flux2D are imported and During the scanning induction harden- mapped into DANTE. The mapping ing process, the axle is positioned verti- Inductor design must prevent cracking process is implemented at 0.5-s inter- cally with the flange on the bottom of and excessive distortion. A machined vals, and the power between two power the fixture. The distance between induc- two-turn coil with a Fluxtrol A magnetic snapshots is linearly interpolated. Figure tor and spray is 25.4 mm. The process flux concentrator was configured using 2b shows temperature distributions pre-

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transformation. The displacement in Fig. 3 is magnified 10 times, so shape change can be clearly viewed.

Cooling rate has a significant effect on residual stresses in the part. Figure 4 (left) shows axial residual stresses pre- dicted using the three cooling rates with HTPRO 22 heat transfer coefficients of 5, 12, and 25 kW/m2 C. A faster cooling rate generates higher residual compression on the sur- face. To balance the surface stress, the core also shows higher tension. The highest tensile stress in the axial direc- tion is located at the centerline of the shaft above the flange, which is mainly due to the extra heat required to harden Fig. 3 — From left to right: temperature, austenite phase, hoop stress, radial displacement, the fillet. Predicted axial displacements and axial displacement distributions at the end of 16.5 s in the induction heating process: Heat transfer coefficient = 25 kW/m2 C. for the three cases are shown in Fig. 4 (right). Axial growth is predicted for all cases. The same legend is used for the three con- tours in Fig. 4 (right), so the color difference represents the magni- tude of axial distor- tion. Axial displace- ment in the shaft is not linearly distributed along the axis, because it is not stabilized dur- ing early scanning of the shaft. Axial dis- Fig. 4 — Axial residual stresses (left) and dicted by DANTE at various times of the placement from the center to the sur- axial distortions predicted from three quenching rate models (right). process. Temperatures predicted by face of the shaft varies. Comparing the Flux2D and DANTE agree well. three cases modeled shows that a higher cooling rate leads to higher axial Stress and phase-transformation growth. HTPRO modeling The first step of the induction hardening References 1. G. Goldstein, V. Nemkov, and J. Jack- process is a 9 s dwell allowing heat to owski, Virtual Prototyping of Induction build in the flange/fillet region; the in- Heat Treating, 25th ASM Heat Treating ductor is stationary with no spray Society Conf., 2009. quenching. Following the dwell, the in- 2. B. Ferguson and W. Dowling, Predictive ductor moves up at a speed of 15 mm/s Model and Methodology for Heat Treat- for 1.5 s, after which the speed drops to ment Distortion, NCMS Report 0383RE97, 8 mm/s and spray quench starts and 1997. 3. V. Nemkov, R. Goldstein, and J. Jack- continues for the duration of the owski, Stress and Distortion Evolution process. Power and temperature distri- During Induction Case Hardening of Tube, butions are stable during scanning over 26th ASM Heat Treating Society Conf., most of the shaft length. Figure 3 shows 2011. temperature, austenite, hoop stress, and Fluxtrol A is a registered trademark of radial and axial displacements at 16.5 s Fluxtrol Inc. DANTE is a registered trade- after the process begins, using a 25 mark of DANTE Software. Flux2D is a reg- kW/m2 C heat transfer coefficient as a istered trademark of Cedrat. boundary condition. The austenite layer For more information: Zhichao (Charlie) transforms to martensite during spray Li is principal engineer, DANTE Software, quenching. Figure 3c shows in-process 7261 Engle Rd., Suite105, Cleveland, OH hoop stress distribution, which shows 44130, 440/876-7578, zli@deformationcon- the effect of thermal gradient and phase trol.com, www.deformationcontrol.com.

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Gas inlet Gas inlet

Active screen (cathode) HTPRO 24 (anode) Furnace wall

Work table (cathode) Work table (floating) Bias Pulse Pulse generator generator generator

(a) Gas outlet (b) Gas outlet Fig. 1 — Schematic view of DC (a) and AS (b) plasma nitriding systems. ACTIVE SCREEN PLASMA NITRIDING NITRIDED LAYERS PRODUCED USING ACTIVE SCREEN PLASMA NITRIDING (ASPN) CAN MEET PERFORMANCE REQUIREMENTS IN A WIDE RANGE OF APPLICATIONS.

H.-J. Spies, H. Biermann, I. Burlacov, Plasma nitriding and plasma nitrocar- and duty cycle[1]. However, even when and K. Börner burizing are used to improve wear and operating state-of-the-art plasma nitrid- TU Bergakademie Freiberg, Institute of corrosion resistance, as well as fatigue ing systems equipped with multizone Materials Engineering, Germany strength of steel components. Compared wall heaters and running in fully auto- with conventional gas and salt-bath ni- mated pulsed discharge mode, close at- triding methods, plasma nitriding offers tention must be paid to the uniformity advantages of lower energy and gas con- of component geometry and the sumption and the ability to be integrated arrangement of parts in the chamber. into in-line manufacturing processes. The process is environmentally friendly ASPN process as well. Additionally, partial nitriding is New plasma nitriding capabilities evolved possible by masking areas where nitrid- with the development of the “active ing is not required; surface enrichment screen process,” in which the plasma dis- with nitrogen and carbon occurs only at charge is applied to a metal mesh screen areas exposed to the plasma glow dis- (active screen) surrounding the entire charge. Glow-seam thickness is highly workload, rather than directly onto the dependent on process parameters, espe- components[2]. Highly reactive gas species cially gas pressure. Adjusting working are produced on the active screen and di- pressure improves the plasma seam for rected to the component surface. The true shape coverage of components with principles of the ASPN process are based a complex geometry. on the well known phenomenon of ni- triding in “after glow[3].” Another function Limitations of plasma nitriding stem from of the active screen is to heat the work- applying the plasma discharge energy di- load by radiation, providing a very uni- rectly onto the surface of parts to be form temperature throughout the entire treated, resulting in a nonhomogeneous load independent of the complexity of temperature distribution through the component geometry. Schematics of workload, especially for components with equipment and experimental arrange- different surface-to-volume ratios. There- ment for the ASPN process and conven- fore, only parts with similar geometries tional DC plasma nitriding (DCPN) are can be treated together in the same batch. shown in Fig. 1. Fig. 2 — Active screen plasma nitriding of 22,000 piston rings. Courtesy of J. Furthermore, parts must be arranged in Georges. the chamber in a specific manner. In ASPN, parts to be treated are placed on a worktable with a floating or nega- Plasma nitriding equipment can be im- tive (cathode) potential (bias) applied. proved by placing resistance heating el- Flow of the active species generated on ements in the furnace wall and the active screen and directed onto the implementing pulsed mode plasma dis- components is effectively controlled charge with controlled pulse frequency using the bias voltage setting. Bias power

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applied to the workload in ASPN does 800 not exceed 10% of the discharge power g¢ used in conventional plasma nitriding, which enables processing dense loads -1 600 g¢ + e without the risk of hollow cathodes and HTPRO arcing. Application of bias is essential in 400 large industrial scale ASPN units to ob- tain the desired nitriding result[4].

Intensity/Imp.s 200 g¢ 25 Figure 2 shows a dense workload con- g¢ e sisting of about 22,000 Type AISI 304 0 20 30 40 50 60 70 80 0 10 mm stainless steel piston rings that were (a) Diffraction angle 2 q /grad (b) treated in a single batch using the ASPN Fig. 3 — XRD-pattern (a) and metallographic cross section (b) of the active screen plasma process. Treating a similar workload in a nitrided sample of 1045 carbon steel with g¢ compound layer: TN = 580°C, tN = 4 h. conventional plasma nitriding unit is not possible. Even using gas nitriding, sur- µm below the surface. It is possible to 16 produce a nitrided layer free of a com- face activation of the high-alloy steel 4142 alloy steel would present severe problems due to pound layer without a reduction of edge H11 tool steel m

the influence of various uncontrollable hardness due to the fine control of ni- m 12 parameters in the pretreatment step. triding potential in ASPN. Reduction of edge hardness is often an issue when ni- 8 ASPN involves a large number of inde- triding using low nitriding potential. pendent process parameters to produce 4 a desired nitrided layer. Controlled Figure 5 shows a key advantage of CL thickness, plasma nitriding and nitrocarburizing in ASPN—uniform nitriding a 304 stainless the ASPN process enables producing an steel component with multiple 0.1-mm 0 diameter drill holes, which confirms the 0 0.13 0.26 0.39 entire spectrum of nitrided-layer struc- (a) Bias, W/in.2 tures—from a nitrided layer without a high reactivity of the gas species gener- compound layer, through a mixed g¢ + ε ated at the active screen. Bias 600 2 phase, to a pure ε-phase compound 0.13 W/in. 2 ASPNC process 0.45 W/in. layer. Composition of the process gas 4142 alloy steel and bias activation are the most impor- Active screen technology is also being 500 tant process parameters. applied to the controlled nitrocarburiz- ing process, called active screen plasma [5] 400 Varying the N2-to-H2 gas ratio in the N2- nitrocarburizing, or ASPNC . Typically,

H2 plasma has a strong influence on com- ε-carbonitride layers are produced in HV0.1 Hardness, conventional plasma nitrocarburizing pound-layer growth rate and structure up 300 to the point of suppressing layer growth. using CH4 and C3H8 as carbon-bearing Figure 3 shows the microstructure of the gases. The risk of cementite precipita- 0 4 8 12 16 20 nitrided layer and the x-ray diffraction tion in the compound layer is still high (b) Distance from surface, mm (XRD) spectrum of the compound layer even at 2% CH4 admixture to the process Fig. 4 — Influence of plasma power density of active screen plasma nitrided 1045 car- gas. This significantly limits the ability to of the bias on white layer thickness of bon steel, which has a single-phase g¢ vary carbon potential of the process gas 4142 alloy steel and H11 tool steel (a) and hardness profile of 4142 (b): TN = 580°C, layer thickness of about 5 mm. in conventional plasma nitrocarburizing tN = 4 h. compared with bath nitriding[6]. Bias activation can also be used to con- trol nitrogen concentration near the In the ASPNC process, the ability to vary component surface. The role of bias bias and process gas composition (dual power in the ASPN process is shown in control) makes it possible to produce car- Fig. 4. An increase in bias power leads to bonitride layers comparable to those ob- a significant improvement of com- tained in bath nitriding. Figure 6 shows a pound-layer thickness. Surface hard- thick, cementite-free ε-carbonitride layer ness, hardness profile, and hardness with 0.85 to 1.0 wt% carbon produced depth are not dependent on compound using the ASPCN process with 3% CH4 layer thickness. admixture and a pressure of 400 Pa.

Nitriding with or without a very thin g¢ Both oxidizing and carburizing effects can phase compound layer typically results be achieved by varying the CO2-to-H2 gas Fig. 5 — True-shape active screen plasma in of the nitrided layer, ratio in the process gas. Carburizing can nitriding of AISI 304 stainless steel parts which prevents precipitation of carbides also be controlled by means of the CO2-to- with 0.1-mm diameter holes. along grain boundaries up to 70 to 100 N2 gas ratio. Figure 7 illustrates the transi-

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results in considerably higher carbon con- 3 N2:H2 (+CH4) = 3:1(+3%) CO :H centration in a thinner compound layer. 8 4 10 2 2 N2:H2 = 3:1 N 0.19 N 1.0 A goal of ongoing investigations is to 3 8 6 2 develop sensor-supported process 6 control in ASPN on the basis of re- 4 2 sults of different plasma diagnostic 4 [7] HTPRO HTPRO C 1 methods . 2 1 Carbon conc., wt% Nitrogen conc., wt% Nitrogen Carbon conc., wt%

26 C conc., wt% Nitrogen 2 References 0 1. H. Wilhelmi, S. Strämke, and H. Pohl, HTM 00 5 10 15 20 25 30 0 0 J. Heat Treatm. Matls., 37, p 263, 1982. (a) Distance from surface, mm 0 5 10 15 20 2. J. Georges, U.S. Patent 5,989,363, 1999; Distance from surface, mm HTM J. Heat Treat. Met., (Birmingham, UK) 80 g¢ + e Fig. 7 — Nitrogen- and carbon- 28, p 33, 2001. concentration profiles of active screen 3. A. Ricard, Surf. & Coat. Technol.,59, p 67, 1993. -1 60 plasma nitrocarburized 4142 alloy steel: 4. P. Hubbard, et al., Surf. & Coat. Technol., TN = 580°C, tN = 4 h. 204, p 1145, 2010. 40 Fe 5. K. Börner, H.-J. Spies, I. Burlacov, and H. Bier- tion from a plasma oxinitriding to the mann, HTM J. Heat Treatm. Matls.,68, p 3, 2013. plasma nitrocarburizing process. 6. T. Lampe, Plasmawärmebehandlung von 20 e

Intensity/Imp.s Eisenwerkstoffen in stickstoff- und kohlen- Process gas for oxinitriding typically has a stoffhaltigen Gasgemischen, Dissertation, 0 Fe C Universität Braunschweig, VDI-Verlag, Reihe 3 CO2-to-H2 gas ratio of 1. A thick com- 20 30 40 50 60 pound layer and high nitrogen concentra- 5, Nr. 93, 1985. (b) Diffraction angle 2q/grad 7. I. Burlacov, et al., Surf. & Coat. Technol., tion are characteristic for the nitrided layer 206, p 3955, 2012. Fig. 6 — Carbon- and nitrogen- obtained with this process. Reducing the For more information: Dr. Igor Burlacov, concentration profiles of active screen CO -to-H gas ratio from 1 to 0.19 and in- plasma nitrocarburized 4142 alloy steel 2 2 TU Bergakademie Freiberg, Institute of (a) and XRD pattern of active screen creasing the CO2-to-N2 gas ratio from Materials Engineering, Gustav-Zeuner-Str. plasma nitrocarburized 1045 carbon steel 0.15 to 0.4 significantly improves the car- 5, 09599 Freiberg, Germany, burlacov@ (b): TN = 580°C, tN = 8 h. burizing effect of the process gas, which tu-freiberg.de, http://tu-freiberg.de.

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