DOCSLIB.ORG

Carburizing of Low-Alloyed Chromium Materials

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Carburizing of Low-Alloyed Chromium Materials Carburizing of Low-Alloyed Chromium Materials – An Overview Sven Bengtsson1, Theodora Marcu2, Alexander Klekovkin3 1Höganäs AB, Höganäs, Sweden, 2 University of Trento, Trento, Italy, 3North American Hoganas Inc, Hollsopple, PA, USA ABSTRACT Case carburizing followed by quench and temper is a well established method of reaching very high properties for components like gears and sprockets. The well established materials on Fe-Cu-Mo-Ni base can all be case hardened using standard equipment and processes. Cr-containing PM materials, with their increased sensitivity to oxidation (and local carbon level), require special considerations. In this paper an overview of how different methods to carburise low alloyed chromium alloyed PM steels will be presented. Among methods discussed are gas carburizing, carbonitriding and vacuum carburizing. Specific emphasis is on selection of appropriate process with regard to density of the components and the formation of carbides. INTRODUCTION In many practical cases the performance of the structural component depends on the mechanical properties of the surface [1,2]. There are many heat treatment methods that focus on improving the properties of the surface. In this paper Gas Carburizing [3-6], Carbonitriding [3,5] and Vacuum Carburizing [3,7-12] will be discussed. These processes aim at achieving a high carbon concentration of carbon at the surface, gradually decreasing towards the core [3]. After austenitizing and quenching high-carbon martensite is formed at the surface while the core will transform into low-carbon martensite, bainite, pearlite, ferrite or a mixture thereof depending on cooling rate and alloy system. A secondary, but very important effect is that the high-carbon martensite will expand on formation and it will expand more than low-carbon martensite or any of the other structures that may form in the core. With a thin expanded surface region compressive stresses will form that are balanced by tensile stresses in the core, but since normally the core is much larger in cross-sectional area the tensile stresses will be lower while the compressive stresses will be significant. These compressive stresses will improve especially the fatigue performance of structural parts loaded in bending; a typical example is bending fatigue of a gear tooth. Presented at PM2008 in Washington, USA on June 9, 2008 1 In case carburizing, a process developed for solid steel, a low carbon (0,15-0,25 wt.% C) low alloy steel is heated to carburizing temperature in the austenite regime (typically 925 oC / 1700 oF) in a gas mixture consisting of CO, CO2, N2 and H2 [e.g. 3]. The nitrogen gas is virtually inert and its only function is as a dilutant and as carrier of heat. The mixture can be created in different ways, but its function as a carburizing agent is depending on the equilibrium of CO, CO2, H2, H2O and of the alloy system [1]. Examining this equilibrium in detail it is found that the amount of H2O is sufficient to oxidize materials based on the Fe-Cr system (e.g. Fe-1.5wt.%Cr alloy). For solid steel parts (e.g. DIN 16MnCr5, AISI 51200) this results in a thin oxidized layer [3,13]. This layer is often removed by e.g. grinding of gear teeth, while sometimes it is accepted. Some oxygen also penetrates the grain boundaries close to the surface forming a thin oxide network [3]. The formation of these oxides causes a depletion of carbon and possibly Chromium resulting in a less hardenable material and a softer structure close to the oxides. The compressive residual stresses will not form to the same extent if oxides are present at the surface [14]. Clearly it is desirable to avoid the formation of these oxides. Carbonitriding is basically the same process as Case Carburizing [3, 5, 15]. The major difference is that Ammonia (NH3) is added, normally towards the end of the carburizing period. The Ammonia decomposes on the surface of the components (and also on the furnace itself) into atomic nitrogen that can penetrate the component and into hydrogen gas. The nitrogen will diffuse into the part in a similar way as carbon does, driven by the concentration difference between the surface and the core. The nitrogen in solution in the austenite will increase the hardenability and therefore, the carbonitriding can be used to obtain martensite in alloy systems that would not normally transform into martensite after an ordinary case carburizing. The problem with oxidation is also present in this system since the equilibria are the same with the exception of the added ammonia. The ammonia influences the carburizing equilibria to small degree only, except that the amount of hydrogen gas increases slightly. However, since the addition of ammonia is normally (at least for PM parts) added towards the end of the austenitization, the oxidation has already taken place and will not revert even if the furnace conditions should improve slightly. Vacuum carburization [3, 7-9] (also referred to as low pressure carburizing) is performed by heating the part in a vacuum furnace to austenitization temperature and introducing a carburizing gas at low pressure into the chamber for a short period of time [1, 3, 10, 16]. The carburizing period is often referred to as the boost step. After this step the steep concentration profile crated during the short time is allowed to be “smoothed out” by diffusion. The boost/diffusion steps are repeated until a satisfactory case depth is reached. The parts are then quenched in gas, normally 6-20 bar of N2, or in oil [17]. Since the vacuum carburization is carried out in vacuum or with a carburizing or inert gas, there is no problem with oxidation. Problems encountered are uneven carburization or problems with quenching in gas. Gas quenching gives a slower quench rate compared to oil and water. If the parts are large or if the parts in the batch are packed tightly the available quench rate may be inadequate. The sintered density is an important parameter since it controls the surface available to the atmosphere [1, 3, 11, 19, 20]. At low densities (<6.8 g/cc) it is very difficult to control the case depth. The penetration of the carburizing gas is so quick that the entire part is carburized [18]. At a higher density it becomes easier to obtain a well defined case depth. At a density above 7.3 g/cc the material starts to behave very much as solid steel [18]. The gas penetration into the parts seems to be insignificant. These findings are true for all three carburizing methods. A consequence of the fast penetration of carburizing gas into the part is that carbides are formed at the surface that would not form in a solid steel of the same chemistry. These carbides are difficult to dissolve during later stages and should be avoided. The alloy system is also important for a successful hardening. The hardenability plays a more significant role the larger the parts become [21,22]. If gas quenching is employed this can be an issue already at sizes of 500 g. Furthermore, the equilibrium at the gas / part interface is also influenced by the alloying system. A steel with Chromium as an alloying element takes up more carbon from the atmosphere compared to a Presented at PM2008 in Washington, USA on June 9, 2008 2 part of pure iron. If Nickel is used as an alloying element the carbon uptake is less than pure iron. In recent years the cost for Molybdenum and Nickel has increased significantly. Furthermore, alternatives in the form of pre-alloyed powders based on Fe-Cr-Mo alloying system have been entering the market. These powders require sintering at low dew points in order avoid oxidation. These requirements apply in principle to the heat treatment process as well. In order to understand how severe the oxidizing problems for these materials are and in order to compare the outcome of a number of competing heat treatments the present investigation was performed. Processes The thermal treatments selected for this investigation are gas carburizing, carbonitriding and vacuum carburizing. Naturally there are more processes available, but these are three of the most interesting surface heat treatments for producing high performance PM parts. The description of the processes aims at showing the main characteristics of the methods without considering the details of all variants available. In some cases pre-treatments, are necessary. It can be the removal of remove surface contaminants, e.g. calibration oil. The presence of these contaminants may change the carburization behaviour. If the density is low it may be necessary to close the surface porosity by steam treating the parts. The heating of the parts must be uniform and the temperature during carburization must be the same for all parts. The furnace atmosphere must also have easy and uninterrupted access to all part surfaces that should be carburized. If parts are stacked on top of each other it can create a shadowing effect that prevents carburization of the surfaces that are not directly in contact with the atmosphere. There must also be free access to all surfaces that should be quenched. This is true regardless whether gas quenching or oil quenching is applied. The parts are then heated to the carburizing temperature. Here two contradicting lines of evolution of the processes are seen. A low carburization temperature will give less distortion after quench directly from the carburizing temperature. However, if the temperature is increased, the carburizing time will decrease significantly and hence the total process time [9]. Since the carburization is controlled by diffusion the temperature is the most powerful parameter in controlling the depth and amount of carbon diffusion into the parts [9, 23].
Load more

Recommended publications
  • Progress the Business and Technology of Heat Treating ® May/June 2008 • Volume 8, Number 3
    An ASM International® HEATPublication TREATING PROGRESS THE BUSINESS AND TECHNOLOGY OF HEAT TREATING ® www.asminternational.org MAY/JUNE 2008 • VOLUME 8, NUMBER 3 HEAT TREATMENT OF LANDING GEAR HEAT TREAT SIMULATION MICROWAVE HEATING SM Aircraft landing gear, such as on this U.S. Navy FA18 fighter jet, must perform under severe loading conditions and in many different environments. HEAT TREATMENT OF LANDING GEAR The heat treatment of rguably, landing gear has Alloys Used perhaps the most stringent The alloys used for landing gear landing gear is a complex requirements for perform- have remained relatively constant operation requiring ance. They must perform over the past several decades. Alloys A under severe loading con- like 300M and HP9-4-30, as well as the precise control of time, ditions and in many different envi- newer alloys AF-1410 and AerMet ronments. They have complex shapes 100, are in use today on commercial temperature, and carbon and thick sections. and military aircraft. Newer alloys like control. Understanding the Alloys used in these applications Ferrium S53, a high-strength stainless must have high strengths between steel alloy, have been proposed for interaction of quenching, 260 to 300 ksi (1,792 to 2,068 MPa) landing gear applications. The typical racking, and distortion and excellent fracture toughness (up chemical compositions of these alloys to100 ksi in.1/2, or 110 MPa×m0.5). are listed in Table 1. contributes to reduced To achieve these design and per- The alloy 300M (Timken Co., distortion and residual formance goals, heat treatments Canton, Ohio; www.timken.com) is have been developed to extract the a low-alloy, vacuum-melted steel of stress.
    [Show full text]
  • Effects of Carburization Time and Temperature on the Mechanical Properties of Carburized Mild Steel, Using Activated Carbon As Carburizer
    Materials Research, Vol. 12, No. 4, 483-487, 2009 © 2009 Effects of Carburization Time and Temperature on the Mechanical Properties of Carburized Mild Steel, Using Activated Carbon as Carburizer Fatai Olufemi Aramidea,*, Simeon Ademola Ibitoyeb, Isiaka Oluwole Oladelea, Joseph Olatunde Borodea aMetallurgical and Materials Engineering Department, Federal University of Technology, Akure, Ondo State, Nigeria bMaterials Science and Engineering Department, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria Received: July 31, 2009; Revised: September 25, 2009 Due to the complexity of controlling parameters in carburization, there has been relatively little work on process variables during the surface hardening process. This work focuses on the effects of the carburizing temperature and time on the mechanical properties of mild steel carburized with activated carbon, at 850, 900 and 950 °C, soaked at the carburizing temperature for 15 and 30 minutes, quenched in oil, tempered at 550 °C and held for 60 minutes. Prior carburization process, standard test samples were prepared from the as received specimen for tensile and impact tests. After carburization process, the test samples were subjected to the standard test and from the data obtained, ultimate tensile strength, engineering strain, impact strength, Youngs’ moduli were calculated. The case and core hardness of the carburized tempered samples were measured. It was observed that the mechanical properties of mild steels were found to be strongly influenced by the process of carburization, carburizing temperature and soaking time at carburizing temperature. It was concluded that the optimum combination of mechanical properties is achieved at the carburizing temperature of 900 °C followed by oil quenching and tempering at 550 °C.
    [Show full text]
  • 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.
    [Show full text]
  • 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.
    [Show full text]
  • 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.
    [Show full text]
  • Distortion in Case Carburized Components- the Steelmakers View
    Heat Treating: Proceedings of the 18th Conference Copyright © 1999 ASM International® Ronald A. Wallis, Harry W. Walton, editors, p 5-11 All rights reserved. DOI: 10.1361/cp1998ht005 www.asminternational.org Distortion in Case Carburized Components­ The Steel makers View M. Cristinacce British Steel Engineering Steels Rotherham, United Kingdom 1. Abstract NVH (noise, vibration and harshness) is becoming of increasing importance in the automotive industry. The control Distortion of components during heat treatment has a of distortion to give correct mating of rotating components significant effect upon final component costs. The factors such as gears and shafts has a major influence upon NVH which influence distortion behaviour occur during the performance. machining and heat treatment processes and are therefore Most of the examples given in this paper are automotive outside the control of the steelmaker. One important factor transmission components which are carburised. which is under the control of the steelmaker is hardenability ­ A wide variety of factors influence distortion behaviour Consistent hardenability performance can have a significant and can be broadly summarised as follows: effect in reducing the variability in distortion. In a number of Component shape. instances it has been shown that the macrostructure and Steel type. as-cast shape of the steel can also influence distortion. Other Microstructure and residual stresses prior to heat downstream processing effects such as forging may also be treatment. influential in these circumstances. Reheating and carburising conditions. This paper gives examples of some of the experiences of Stacking and support in furnace. British Steel Engineering Steels with customers and end users, Quenching - Medium, temperature, flow, jigging, etc.
    [Show full text]
  • 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).
    [Show full text]
  • 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.
    [Show full text]
  • Vacuum Systems and Technologies
    ALD Vacuum Technologies High Tech is our Business Vacuum Systems and Technologies for Metallurgy and Heat Treatment MetaCom / Product Overview / 09.16 Overview / Product MetaCom Worldwide Leading Our Market Position ALD Vacuum Technologies is a market leader in vacuum systems and process services for thermal and thermo-chemical treatment of solid and molten metals. Our Process and Equipment Portfolio Our engineering expertise includes O vacuum process technology O know-how to design customized system solutions for Vacuum Metallurgy Vacuum Heat Treatment and Sintering Nuclear Fuel Production and Waste Management Vacuum Metallurgy Vacuum metallurgy involves vacuum processes for treating molten metals such as melting and remelting, casting and metal-powder technology as well as specialized vacuum coating technologies for high temperature turbine components. Casting and Coating O Vacuum Induction Melting – Investment Casting (VIM-IC) O Cold-Wall Induction Melting and Casting (LEICOMELT) O VAR Skull Melting and Casting (VAR-SM) Applications System Portfolio O Vacuum Turbine Blade Coating (EB/PVD) Examples of products that were developed ALD offers modern, efficiently Photovoltaic using ALD‘s advaced vacuum processes functioning production systems which O Solar silicon melting and include O significantly contributes to the Crystallization Unit (SCU) O highly alloyed special steels and cost-effectiveness of a high quality Powder Atomization superalloys production O Vacuum Induction Melting Gas O refractory and reactive metals with O covers the
    [Show full text]
  • The Effect of Retained Austenite on the Distortion in Carburized SAE 8620 Steel
    University of Windsor Scholarship at UWindsor Electronic Theses and Dissertations Theses, Dissertations, and Major Papers 1-1-2005 The effect of retained austenite on the distortion in carburized SAE 8620 steel. Haitao (Lily) He University of Windsor Follow this and additional works at: https://scholar.uwindsor.ca/etd Recommended Citation He, Haitao (Lily), "The effect of retained austenite on the distortion in carburized SAE 8620 steel." (2005). Electronic Theses and Dissertations. 7166. https://scholar.uwindsor.ca/etd/7166 This online database contains the full-text of PhD dissertations and Masters’ theses of University of Windsor students from 1954 forward. These documents are made available for personal study and research purposes only, in accordance with the Canadian Copyright Act and the Creative Commons license—CC BY-NC-ND (Attribution, Non-Commercial, No Derivative Works). Under this license, works must always be attributed to the copyright holder (original author), cannot be used for any commercial purposes, and may not be altered. Any other use would require the permission of the copyright holder. Students may inquire about withdrawing their dissertation and/or thesis from this database. For additional inquiries, please contact the repository administrator via email ([email protected]) or by telephone at 519-253-3000ext. 3208. THE EFFECT OF RETAINED AUSTENITE ON THE DISTORTION IN CARBURIZED SAE 8620 STEEL by Haitao (Lily) He A Thesis Submitted to the Faculty of Graduate Studies and Research through Engineering Materials
    [Show full text]
  • 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.
    [Show full text]
  • Differences and Applications of Carburizing and Cabonitriding
    DIFFERENCES AND APPLICATIONS OF CARBURIZING AND CABONITRIDING Francisco GUANÍ, Especialidades Térmicas, S.A. de C.V. Fundidores 18 Zona Industrial Xhala Cuautitlán Izcalli, México, C.P. 54714 Carburizing Carburizado También conocido como Endurecimiento de la Capa. Also referred as Case Hardening. Es un tratamiento térmico que produce Is a heat treatment process that una superficie la cual es resistente al produces a surface which is resistant to desgaste, manteniendo la tenacidad y wear, while maintaining toughness and resistencia en el núcleo. strength of the core. Este tratamiento se aplica a partes de This treatment is applied to low carbon acero bajo carbono después de su steel parts after machining, as well as maquinado, también como a aceros de high alloy steel bearings, gears, and rodamiento de alta aleación, engranes y other components. otros componentes. Carburizing increases strength and El carburizado incrementa la tensión y la wear resistance by diffusing carbon resistencia al desgaste, mediante la into the surface of the steel creating a difusión de carbono en la superficie del case while retaining a substantially acero, creando una capa, mientras que el lesser hardness in the core. This núcleo mantiene una menor dureza. Este treatment is applied to low carbon tratamiento se aplica a aceros bajo steels after machining. carbono después de su maquinado. Strong and very hard-surface parts of Partes con superficies duras de formas intricate and complex shapes can be intricadas y complejas se pueden made of relatively lower cost materials obtener a costos relativamente bajos que that are readily machined or formed ya han sido maquinados o formados prior to heat treatment.
    [Show full text]