Distortion in Case Carburized Components- the Steelmakers View
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Higher-Quality Electric-Arc Furnace Steel
ACADEMIC PULSE Higher-Quality Electric-Arc Furnace Steel teelmakers have traditionally viewed Research Continues to Improve the electric arc furnaces (EAFs) as unsuitable Quality of Steel for producing steel with the highest- Even with continued improvements to the Squality surface finish because the process design of steelmaking processes, the steelmaking uses recycled steel instead of fresh iron. With over research community has focused their attention 100 years of processing improvements, however, on the fundamental materials used in steelmaking EAFs have become an efficient and reliable in order to improve the quality of steel. In my lab steelmaking alternative to integrated steelmaking. In at Carnegie Mellon University, we have several fact, steel produced in a modern-day EAF is often research projects that deal with controlling the DR. P. BILLCHRIS MAYER PISTORIUS indistinguishable from what is produced with the impurity concentration and chemical quality of POSCOManaging Professor Editorof Materials integrated blast-furnace/oxygen-steelmaking route. steel produced in EAFs. Science412-306-4350 and Engineering [email protected] Mellon University Improvements in design, coupled with research For example, we recently used mathematical developments in metallurgy, mean high-quality steel modeling to explore ways to control produced quickly and energy-efficiently. phosphorus. Careful regulation of temperature, slag and stirring are needed to produce low- Not Your (Great-) Grandparent’s EAF phosphorus steel. We analyzed data from Especially since the mid-1990s, there have been operating furnaces and found that, in many significant improvements in the design of EAFs, cases, the phosphorus removal reaction could which allow for better-functioning burners and a proceed further. -
Ferritic Nitrocarburizing Gears to Increase Wear Resisitance And
Ferritic Nitrocarburizing Gears tOI Increase Wear Resistance and Reduce Distortion Loren ,JI, Epler uaHtygear manufacturing depends on controlled toler- asa gaseous territic nitrocarl:mrizillg process and patented by ances and geometry. As a re ult, ferritic nillocarburizing Lucas Industries in 1961. Lucas demonstrated that they could ha become the heat treat process of choice for many produce surface layers identical to those produced in salt bath gear manufacturers. The primary reason for this are: processes using an endothermic, ammonia-based atmosphere. The process is performed at low temperatures, i.e. less than The process was classified as a "thermochemical susfece critical treatment" that involved !he diffusion of both nitrogenand car- 2. The quench methods increase fatigue strength by up to, L25% bon into the surface of a metal at a temperature below the au tell- without distorting. Ferritlc nitrocarboriziag is used in place ite transforrnation temperature. The process would yield .3 single of carburizing and hardening, carbonitriding, nltriding or in phase epsilon layer with an atomic weight of Fep3' The ingle conjunction wi.th conventional and induction hardening. phase layer makes !:heproduct much more wear resistant than gas 3. h establishes gradient base haronesses, i.e, eliminates egg- or ionnitriding, according to Dawc and Trantner 0). shell effect on TiN, TiAlN,. ere. etc. [II 1982, lronbeund HeatTreat developed Ni.tmwear® using In addition, the process can also be applied to hobs, broaches, similar atmo pheres in a fluidized bed medium. Subsequently. drills and other cutting tools. Jack Ross, owner and founder of lronbound,. patented and HisUJry, Fenitic nitrocarburizing was first established in licensed the process to Dynamic Metal Treating. -
Carbonitriding and Hard Shot Peening for High-Strength Gears Yoshihisa Miwa, Masayuki Suzawa, Yukio Arimi, Yoshihiko Kojima, and Katsunori Nishimura Mazda Motor Corp
Carbonitriding and Hard Shot Peening for High-Strength Gears Yoshihisa Miwa, Masayuki Suzawa, Yukio Arimi, Yoshihiko Kojima, and Katsunori Nishimura Mazda Motor Corp. ABSTRACT CUE HARONESS HARONESS CUE OEtrM A new process for manufacturing high- OISTRIBUTION --E CORE HARONESS strength gears has been developed to meet the requirement of automobile transmission minia- r turization. The points of the process are to GRAIN SIZE increase the shot peening intensity and to MICROSTRUCTURE perform optimal control of the initial (before FATIGUE CARBIOES shot peening) microstructure by heat treatment STREMGTH MON-MARTEMSITIC corresponding with the peening intensity in OEFEtTS -r SURFACEUOU-METALLIC LAYER order to obtain higher residual compressive IuCLUSlONS stress. INTERGRANULAR i TOUGHMESS The new process, named Carbonitriding and Hard Shot Peening in Mazda, brings a much RESlOUAL COYIRESIVE STRESS higher fatigue strength than the one obtained by the conventional carburizing and shot peening process. Fig. 1 METALLURGICAL FACTORS AFFECTING ON THE FATIGUE STRENGTH OF GEARS 1. Introduction A higher drivability, stability in therefore, it is necessary to set a suitable driving, and fuel efficiency are required for i~ardnessdistribution by heat treatment using automobiles and the new systems to meet these clean material. However, in order to augment requirements have been developed. This can the fatigue strength furthermore, it is nec- be seen, for example, in multi-valve system, essary to make use of residual compressive super charging in engines, 4 WD or 4 WS, etc. stress more positively. In addition, the height of engine hood has For enlargement of the residual compressive been lowered in body designing for reducing stress, it is most effective to increase the air resistance. -
Carburizing & Carbonitriding
CARBURIZING & CARBONITRIDING A TRADITIONAL SURFACE HARDENING TREATMENT WITH MODERN PROCESS CONTROLS WHAT IS IT? HOW IS IT DONE? General Description of Carburizing & Carbonitriding Equipment & Process Carburizing is a process of controlled diffusion of carbon into Solid, molten salt and gaseous carbon-carrying medium may the surface of a component, followed by quenching and be employed, however, the first two are now rarely used. tempering, with the objective of increasing the component’s Nitrex offers gas carburizing in computer controlled integral surface hardness. The process is generally applicable to low quench and pit gas carburizing furnaces. A full range of case carbon and low alloy steels. There are two carburizing depths if feasible with an economically derived limit of process types available commercially – vacuum carburizing approximately 0.250” (6.4 mm). In addition, Nitrex offers and conventional carburizing. The former is described in a vacuum carburizing which is described in a separate separate brochure, and conventional carburizing is company publication. discussed here. The sequence of operations is as follows : In this thermal process ferrous alloys are heated to above • parts are appropriately fixtured, loaded into the furnace, their transformation temperature and exposed to carbon rich and the process is initiated atmosphere. Processing temperatures in conventional • carburizing typically are in the 1450°F - 1900°F (790°C - computers and/or process controllers are programmed to 1040°C) range. The diffusion of carbon into the part and the conduct the process automatically, subsequent quench leads to a part with a hard, wear • at the end of the process the load is either direct resistant surface and a tough, shock resistant core. -
Decarbonising Steelmaking: Technology Options and Regional Pathways
Decarbonising steelmaking: technology options and regional pathways Huw McKay Chief Economist Ben Ellis Head of Marketing Strategy and Technical Marketing Wenjun Bao Manager Steel and Nonferrous Analysis Lee Levkowitz Manager Energy and Technology Research 11 November 2020 Disclaimer Forward-looking statements This presentation contains forward-looking statements, including statements regarding: trends in commodity prices and currency exchange rates; demand for commodities; production forecasts; plans, strategies and objectives of management; closure or divestment of certain assets, operations or facilities (including associated costs); anticipated production or construction commencement dates; capital costs and scheduling; operating costs and shortages of materials and skilled employees; anticipated productive lives of projects, mines and facilities; provisions and contingent liabilities; and tax and regulatory developments. Forward-looking statements may be identified by the use of terminology, including, but not limited to, ‘intend’, ‘aim’, ‘project’, ‘anticipate’, ‘estimate’, ‘plan’, ‘believe’, ‘expect’, ‘may’, ‘should’, ‘will’, ‘would’, ‘continue’, ‘annualised’ or similar words. These statements discuss future expectations concerning the results of assets or financial conditions, or provide other forward-looking information. These forward-looking statements are based on the information available as at the date of this release and are not guarantees or predictions of future performance, and involve known and unknown risks, uncertainties and other factors, many of which are beyond our control, and which may cause actual results to differ materially from those expressed in the statements contained in this release. BHP cautions against reliance on any forward-looking statements or guidance, particularly in light of the current economic climate and the significant volatility, uncertainty and disruption arising in connection with COVID-19. -
Carburizing & Carbonitriding Control Solutions For
CARBURIZING & CARBONITRIDING CONTROL SOLUTIONS FOR BATCH FURNACES RETROFITS & NEW FURNACES CARBURIZING & CARBONITRIDING CONTROL SOLUTIONS OTHER CONTROL SOLUTIONS STANDARD EQUIPMENT • Protherm 455, 500, 600 or 700 controller (see separate brochures for more details) • Hi-limit temperature controllers for furnace & oil bath • Steel plate (mountable) or cabinet (enclosure) • DIN mounted hardware • Pre-wired with terminal blocks & isolation relays • Electrical drawing / user manual • Smart transmitter (allows probe care) Annealing MAIN FEATURES • Precise atmosphere control (carbon potential control) • Furnace temperature control • Quench (oil) temperature control • Alarm notification and processing • Password protected interface • Real time and historical paperless chart recorder displaying process variables • Recipes and templates can be created and modified Induction OPTIONAL FEATURES • Online carbon & nitrogen diffusion modulefor more precise control. Includes: target control / surface carbon control / soot carbon control / auto boost / auto diffusion / calculates carbon profile & hardness curve • ß-control module for more precise control & savings. Includes: online carbon diffusion module plus shortens process time and reduces energy, gas consumption and exhaust • Dual probe reliability function (with additional smart Nitriding transmitter) • Additional I/O cards: 3-gas I/R, Cascade heating control INTEGRATION / CONNECTION • Integrated web server • CANopen / DeviceNet interfaces • RS485/422 4 wire Modbus / J-bus • RJ45 Ethernet LAN interface for configuration • Seamless integration with SCADA • Modbus / TCP interface Vacuum • Optional Profibus slave or master USA CANADA CHINA FRANCE GERMANY POLAND +1 414 462 8200 +1 514 335 7191 +86 21 3463 0376 +33 3 81 48 37 37 +49 7161 94888 0 +48 32 296 66 00 [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] Copyright © United Process Controls (Broc701rev7). -
An Introduction to Nitriding
01_Nitriding.qxd 9/30/03 9:58 AM Page 1 © 2003 ASM International. All Rights Reserved. www.asminternational.org Practical Nitriding and Ferritic Nitrocarburizing (#06950G) CHAPTER 1 An Introduction to Nitriding THE NITRIDING PROCESS, first developed in the early 1900s, con- tinues to play an important role in many industrial applications. Along with the derivative nitrocarburizing process, nitriding often is used in the manufacture of aircraft, bearings, automotive components, textile machin- ery, and turbine generation systems. Though wrapped in a bit of “alchemi- cal mystery,” it remains the simplest of the case hardening techniques. The secret of the nitriding process is that it does not require a phase change from ferrite to austenite, nor does it require a further change from austenite to martensite. In other words, the steel remains in the ferrite phase (or cementite, depending on alloy composition) during the complete proce- dure. This means that the molecular structure of the ferrite (body-centered cubic, or bcc, lattice) does not change its configuration or grow into the face-centered cubic (fcc) lattice characteristic of austenite, as occurs in more conventional methods such as carburizing. Furthermore, because only free cooling takes place, rather than rapid cooling or quenching, no subsequent transformation from austenite to martensite occurs. Again, there is no molecular size change and, more importantly, no dimensional change, only slight growth due to the volumetric change of the steel sur- face caused by the nitrogen diffusion. What can (and does) produce distor- tion are the induced surface stresses being released by the heat of the process, causing movement in the form of twisting and bending. -
Technical Progress in Steelmaking and Casting for Special Bar and Wire Steel at Muroran Works
NIPPON STEEL TECHNICAL REPORT No. 104 AUGUST 2013 Technology UDC 669 . 184 . 244 . 66 : 669 . 14 - 422 Technical Progress in Steelmaking and Casting for Special Bar and Wire Steel at Muroran Works Masato KOBAYASHI* Kohichi ISOBE Masayuki ARAI Abstract Muroran Works, Nippon Steel Corporation manufactures special bars and wire rods mainly for automotive parts. In steelmaking plant, many technologies have been developed to manufacture high grade special steel and to suit the users’ various needs, e.g. multi-refin- ing converter (MURC), secondary steelmaking and casting to improve steel cleanliness, and near net casting and compact high reduction process (NCR). Authors describe recent ad- vances and prospects in steelmaking and casting technologies for manufacturing special steel in Muroran Works. 1. Introduction 2. Outline of Muroran Works Founded in 1909, Nippon Steel Corporation’s Muroran Works In 1994, the ironmaking department of Muroran was separated (hereinafter simply called “Muroran”) is the only integrated iron and from Nippon Steel Muroran Works, and the former was used to es- steel works in Hokkaido and manufactures special steels for bars tablish 80% of a joint venture with MSR, known as Hokkai Iron & and wire rods. Nearly 90% of the products of Muroran are special Coke Corporation. Since then, Hokkai Iron & Coke has been the steels, which are used mainly for critical automotive components supplier of hot metal to Muroran᾽s basic oxygen furnace (converter) (the engine, driving system, and undercarriage) and various parts of and electric furnace. The steel source used at Muroran is converter industrial machinery and construction equipment (Fig. 1). Since 1994, Muroran has also been manufacturing bars and wire rods in cooperation with Mitsubishi Steel Muroran, Inc. -
Steelmaking by Electric Arc Furnaces Cleaner, More Efficient
EVRAZ Canadian Steel: Low Carbon Footprint November 2016 Electric Arc Furnaces (EAFs) with metal scrap: cleaner, more efficient • EVRAZ Regina utilizes two Electricity Steelmaking EAFs to make up to 1.1 Generation million tons of steel per Energy used CO2 emissions CO2 emissions year kg / ton of steel kWh / ton of steel grams / kWh -79% • Over 91% of steelmaking -64% -81% 2,081 in China is from Blast 4,624 764 Oxygen Furnaces (BOFs), which use iron ore, coking coal, and other inputs • For every one ton of steel scrap made into new steel, over 1,400kg of iron ore, 1,647 740kg of coal, and 120kg 441 147 of limestone are saved Overseas input shipping to China Blast EAF Blast EAF China Canada Furance Furnace Sources: BOF percentage: Worldsteel. Shipping emissions: National Technical University of Athens. Steelmaking: Midrex – Blast Furnace assuming 11% Scrap, EAF Use of 100% scrap. Scrap statistics: Worldsteel. Electricity Generation: IEA 2011 2 EVRAZ cleaner EAFs, Canada’s power generation outpace others Emissions from Steelmaking emissions and energy use energy generation Energy used CO2 emissions CO2 emissions kg / ton of steel kWh / ton of steel grams / kWh -79% -64% 2,081 4,624 -81% 764 1,526 3,419 2,327 476 470 929 1,647 441 147 China Germany Turkey EVRAZ Blast GermanyTurkey EAF China Turkey Germany Canada - BOF Canada Furnace - EAF - China Overseas shipping of inputs Sources: BOF percentage: Worldsteel. Shipping emissions: National Technical University of Athens, from China to BC, Europe to Houston. Steelmaking: Midrex – Blast Furnace assuming 11% Scrap, EAF Use of 100% scrap. -
The Future of Steelmaking– Howeuropean the MANAGEMENT SUMMARY
05.2020 The future of steelmaking – How the European steel industry can achieve carbon neutrality MANAGEMENT SUMMARY The future of steelmaking / How the European steel industry can achieve carbon neutrality The European steelmaking industry emits 4% of the EU's total CO2 emissions. It is under growing public, economic and regulatory pressure to become carbon neutral by 2050, in line with EU targets. About 60% of European steel is produced via the so-called primary route, an efficient but highly carbon-intensive production method. The industry already uses carbon mitigation techniques, but these are insufficient to significantly reduce or eliminate carbon emissions. The development and implementation of new technologies is underway. With limited investment cycles left until the 2050 deadline, the European steelmaking industry must decide on which new technology to invest in within the next 5-10 years. We assess the most promising emerging technologies in this report. They fall into two main categories: carbon capture, use and/or storage (CCUS), and alternative reduction of iron ore. CCUS processes can be readily integrated into existing steel plants, but cannot alone achieve carbon neutrality. If biomass is used in place of fossil fuels in the steelmaking process, CCUS can result in a negative carbon balance. Alternative reduction technologies include hydrogen-based direct reduction processes and electrolytic reduction methods. Most are not well developed and require huge amounts of green energy, but they hold the promise of carbon-neutral steelmaking. One alternative reduction process, H2-based shaft furnace direct reduction, offers particular promise due to its emissions-reduction potential and state of readiness. -
AISI | Electric Arc Furnace Steelmaking
http://www.steel.org/AM/Template.cfm?Section=Articles3&TEMPLATE=/CM/HTMLDisplay.cfm&CONTENTID=12308 Home Steelworks Home Electric Arc Furnace Steelmaking By Jeremy A. T. Jones, Nupro Corporation SIGN UP to receive AISI's FREE e-news! Read the latest. Email: Name: Join Courtesy of Mannesmann Demag Corp. FURNACE OPERATIONS The electric arc furnace operates as a batch melting process producing batches of molten steel known "heats". The electric arc furnace operating cycle is called the tap-to-tap cycle and is made up of the following operations: Furnace charging Melting Refining De-slagging Tapping Furnace turn-around Modern operations aim for a tap-to-tap time of less than 60 minutes. Some twin shell furnace operations are achieving tap-to-tap times of 35 to 40 minutes. 10/3/2008 9:36 AM http://www.steel.org/AM/Template.cfm?Section=Articles3&TEMPLATE=/CM/HTMLDisplay.cfm&CONTENTID=12308 Furnace Charging The first step in the production of any heat is to select the grade of steel to be made. Usually a schedule is developed prior to each production shift. Thus the melter will know in advance the schedule for his shift. The scrap yard operator will prepare buckets of scrap according to the needs of the melter. Preparation of the charge bucket is an important operation, not only to ensure proper melt-in chemistry but also to ensure good melting conditions. The scrap must be layered in the bucket according to size and density to promote the rapid formation of a liquid pool of steel in the hearth while providing protection for the sidewalls and roof from electric arc radiation. -
Furnace Atmospheres No 1: Gas Carburising and Carbonitriding
→ Expert edition Furnace atmospheres no. 1. Gas carburising and carbonitriding. 02 Gas carburising and carbonitriding Preface. This expert edition is part of a series on process application technology and know-how available from Linde Gas. It describes findings in development and research as well as extensive process knowledge gained through numerous customer installations around the world. The focus is on the use and control of furnace atmospheres; however a brief introduction is also provided for each process. 1. Gas carburising and carbonitriding 2. Neutral hardening and annealing 3. Gas nitriding and nitrocarburising 4. Brazing of metals 5. Low pressure carburising and high pressure gas quenching 6. Sintering of steels Gas carburising and carbonitriding 03 Passion for innovation. Linde Gas Research Centre Unterschleissheim, Germany. With R&D centres in Europe, North America and China, Linde Gas is More Information? Contact Us! leading the way in the development of state-of-the-art application Linde AG, Gases Division, technologies. In these R&D centres, Linde's much valued experts Carl-von-Linde-Strasse 25, 85716 Unterschleissheim, Germany are working closely together with great access to a broad spectrum of technology platforms in order to provide the next generation of [email protected], www.heattreatment.linde.com, atmosphere supply and control functionality for furnaces in heat www.linde.com, www.linde-gas.com treatment processes. As Linde is a trusted partner to many companies in the heat treatment industry, our research and development goals and activities are inspired by market and customer insights and industry trends and challenges. The expert editions on various heat treatment processes reflect the latest developments.