Modeling Precipitation Hardening and Yield Strength in Cast Al-Si-Mg-Mn Alloys
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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. -
Effect of Alloying Elements on Heat Treatment Behavior of Hypoeutectic
Materials Transactions, Vol. 47, No. 1 (2006) pp. 72 to 81 #2006 The Japan Institute of Metals Effect of Alloying Elements on Heat Treatment Behavior of Hypoeutectic High Chromium Cast Iron Sudsakorn Inthidech1;*, Prasonk Sricharoenchai1 and Yasuhiro Matsubara2 1Department of Metallurgical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok10330, Thailand 2Department of Metallurgical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok10330, Thailand The relationship between hardness and volume fraction of retained austenite (V ) was investigated in heat-treated 16 mass% and 26 mass%Cr hypoeutectic cast irons with and without addition of a third alloying element of Ni, Cu, Mo and V. In as-hardened state, hardness changed remarkably depending on the V . Overall, Ni and Cu decreased hardness but Mo increased it. Hardness increased in 16 mass%Cr cast iron but decreased in 26 mass%Cr cast iron by V addition. The V increased with Ni, Cu and Mo addition but diminished with V addition in 16 mass%Cr cast iron. In 26 mass%Cr cast iron, Ni and Mo increased the V but Cu and V reduced it. Higher austenitization caused more V . Curves of tempered hardness showed an evident secondary hardening due to precipitation of special carbides and transformation of destabilized austenite into martensite. High tempered hardness was obtained in the specimens with high V in as-hardened state. Maximum tempered hardness (HTmax) was obtained when V was less than 20% and it increased with an increase in Mo content. The HTmax slightly increased with V content in 16 mass%Cr cast iron and decreased in 26 mass%Cr cast iron. -
Effect of Tempering Conditions on Secondary Hardening of Carbides
materials Article Effect of Tempering Conditions on Secondary Hardening of Carbides and Retained Austenite in Spray-Formed M42 High-Speed Steel Bowen Liu 1,*, Tian Qin 2, Wei Xu 1, Chengchang Jia 1,*, Qiuchi Wu 2, Mingying Chen 2 and Zhe Liu 2 1 Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China; [email protected] 2 School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China; [email protected] (T.Q.); [email protected] (Q.W.); [email protected] (M.C.); [email protected] (Z.L.) * Correspondence: [email protected] (B.L.); [email protected] (C.J.); Tel.: +86-15-210-565-349 (B.L.) Received: 30 October 2019; Accepted: 7 November 2019; Published: 11 November 2019 Abstract: In this study, the effect of tempering conditions on microstructure, grain size, and carbide phase compositions of spray-formed high-speed steel after quenching at 1180 ◦C was studied. The influence of carbide phase, size of carbides, and retained austenite content on secondary hardening of the steel was analyzed by field emission scanning electron microscope (FESEM), transmission electron microscope (TEM), electron backscattered diffraction (EBSD), and differential scanning calorimetry (DSC); the hardness, microhardness of carbide, and bending strength were tested. The results show that M3C, M6C, M7C3, and MC carbides may precipitate at different tempering temperatures and the transformation of the retained austenite can be controlled by tempering. The phase composition of carbides, microstructure, and retained austenite content strongly influences the performance characteristics of M42 high-speed steel after tempering. -
History of the Hardening of Steel : Science and Technology J
HISTORY OF THE HARDENING OF STEEL : SCIENCE AND TECHNOLOGY J. Vanpaemel To cite this version: J. Vanpaemel. HISTORY OF THE HARDENING OF STEEL : SCIENCE AND TECHNOLOGY. Journal de Physique Colloques, 1982, 43 (C4), pp.C4-847-C4-854. 10.1051/jphyscol:19824139. jpa- 00222126 HAL Id: jpa-00222126 https://hal.archives-ouvertes.fr/jpa-00222126 Submitted on 1 Jan 1982 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. JOURNAL DE PHYSIQUE Colloque C4, suppZ4ment au no 12, Tome 43, de'cembre 1982 page C4-847 HISTORY OF THE HARDENING OF STEEL : SCIENCE AND TECHNOLOGY 3. Vanpaemel Center for historical and socio-economical studies on science and technology Teer EZstZaan 41, 3030 Leuven, SeZgim (Accepted 3 November 1982) Abstract. - The knowledge of the hardening phenomenon was achieved through a very cumulative process without any dis- continuity or 'scientific crisis' . The history of the hardening shows a definite interrelationship between techno- logical approach (or the application-side) and academic science . The hardening of steel appears to have been an operation in common use among the early Greeks The Greek and Roman smiths knew, from experience, how to control the. -
The Stainless Steel Family
The Stainless Steel Family A short description of the various grades of stainless steel and how they fit into distinct metallurgical families. It has been written primarily from a European perspective and may not fully reflect the practice in other regions. Stainless steel is the term used to describe an extremely versatile family of engineering materials, which are selected primarily for their corrosion and heat resistant properties. All stainless steels contain principally iron and a minimum of 10.5% chromium. At this level, chromium reacts with oxygen and moisture in the environment to form a protective, adherent and coherent, oxide film that envelops the entire surface of the material. This oxide film (known as the passive or boundary layer) is very thin (2-3 namometres). [1nanometre = 10-9 m]. The passive layer on stainless steels exhibits a truly remarkable property: when damaged (e.g. abraded), it self-repairs as chromium in the steel reacts rapidly with oxygen and moisture in the environment to reform the oxide layer. Increasing the chromium content beyond the minimum of 10.5% confers still greater corrosion resistance. Corrosion resistance may be further improved, and a wide range of properties provided, by the addition of 8% or more nickel. The addition of molybdenum further increases corrosion resistance (in particular, resistance to pitting corrosion), while nitrogen increases mechanical strength and enhances resistance to pitting. Categories of Stainless Steels The stainless steel family tree has several branches, which may be differentiated in a variety of ways e.g. in terms of their areas of application, by the alloying elements used in their production, or, perhaps the most accurate way, by the metallurgical phases present in their microscopic structures: . -
The Discovery of Strong Aluminum
METALS HISTORY The Discovery of Strong Aluminum Charles R. Simcoe ow did aluminum, a metal that is light Interest in Wilm’s alloy spread throughout Watseka, Ill. H in weight (only one-third as heavy as the metal-making world. Samples of the alloy steel) and in its unalloyed form is were obtained, and studies were undertaken on The discovery among the weakest of all metals, become the the hardening mechanism at the United States structural material of modern airplanes? This Bureau of Standards in Washington, D.C. The of age story started in the very early 1900s, the in- research was performed by Paul Merica, hardening of fancy of the aluminum industry. At this time, Howard Scott, and R.G. Waltenberg, and they aluminum was the aluminum market was mostly in cooking would become famous as the next major con- a seminal utensils, pots, and pans. The leap from such tributors to the amazing story of age harden- small, mundane beginnings to building Zep- ing. They found that nature had held a secret event in the pelins in a few years, Douglas DC-3s in 25 on a method of hardening metals, and that history of years, and Boeing 747s in 60 years is a remark- Wilm’s alloy was just a single example of a uni- metals. able feat of engineering. versal behavior that was undiscovered since an- Read the The first character in this drama was a Ger- cient man had learned to make alloys during complete man engineer by the name of Alfred Wilm. He the age of bronze. -
Evaluation of the Mechanical Properties After Thermal Treatment of a Structural Hot Rolled Multiphase Steel(·)
REVISTA DE METALURGIA, 43 (6) NOVIEMBRE-DICIEMBRE, 448-457, 2007 ISSN: 0034-8570 Evaluation of the mechanical properties after thermal treatment of a structural hot rolled multiphase steel(·) J. Asensio-Lozano* and J.T. Panta-Mesones** Abstract The present paper corresponds to the experimental study conducted on a hot rolled (HR) multiphase (MP) steel, in which hardness, tensile and toughness properties were measured after the application of a series of subcritical and intercritical heat treatments (HT) to the hot rolled stock. The aforementioned values were compared to the corresponding ones in the as-rolled state and after normalizing. The microstructure in the longitudinal plane of the strip was analyzed by light optical microscopy in the as-rolled state and in the HT samples. Longitudinal (L) and transverse (T) tensile and toughness specimens were cut to characterize every condition studied. Toughness properties were evaluated by means of Charpy V-notch tests conducted at 20 °C, 0 °C, –20 °C, –40 °C, –60 °C and –80 °C . It was observed that the yield stress increased with the increase in the heat treatment temperature in the subcritical range, while the tensile strength decreased slightly over the same range of temperatures. Uniform and total elongation only showed a slight improvement when the treatment was conducted at 620 °C and 700 °C, while the best toughness response corresponded to the sample treated at 500 °C for operating temperatures comprised between –40 °C and room temperature (RT). Keywords Multiphase steels. Heat treatment. Tempering. Normalizing. Mechanical properties. Hardness. Tension test. Charpy impact toughness. Evaluación de las propiedades mecánicas tras tratamiento térmico de un acero multifase estructural laminado en caliente Resumen El presente estudio corresponde al trabajo experimental desarrollado en un acero multifase laminado en caliente, en el que se evaluaron las propiedades de dureza, tracción y tenacidad a impacto, tras realizar tratamientos térmicos subcríticos e intercríticos al material laminado en caliente. -
Case Hardening Steel–Aisi 8620
CASE HARDENING STEEL–AISI 8620 AISI 8620 Nickel–Chrome–Moly TYPICAL CHEMICAL ANALYSIS Carburising Steel, generally supplied Carbon 0.20% as rolled to HB 255max. Carburised Silicon 0.25% and heat treated it develops a hard Manganese 0.80% wear resistant case to HRC 60-63 and Chromium 0.50% Nickel 0.55% a tough strong core with a typical Molybdenum 0.20% tensile strength range of 700-1100 MPa, in small to medium sized sections. RELATED SPECIFICATIONS: AS 1444-1996 8620 or 8620H TYPICAL APPLICATIONS: 1.6523 20NiCrMo2-2 or Arbors, pinions, bushes, camshafts, kingpins, EN10084-1998 ratchets, gears, splined shafts etc. Or can be 1.6523H 20NiCrMo2-2H used for high tensile applications uncarburised but JIS G 4103 SNCM 220 or through hardened and tempered. JIS G 4052 SNCM 220H UNS G86200 or H86200 . Through hardening properties fair with good toughness due to the low carbon and medium alloy content, also suitable for Nitriding. TYPICAL MECHANICAL PROPERTIES – Quenched and Tempered at 200°C Section Yield Strength Tensile Strength Elongation Impact Izod Hardness mm MPa MPa % J HB 25 690 925 17 46 275 100 493 740 20 50 220 Typical Mechanical Properties for guidance only HARDENABILITY LIMITS – FOR AS1444 – 8620H GRADE Distance from quenched end – mm Hardness values max - min – HRC (values under 20 not specified) mm 1.5 3 5 7 9 11 13 15 20 25 30 35 40 HRC 48 47 43 39 35 32 30 29 26 24 23 23 23 HRC 41 37 31 25 21 - - - - - - - - CASE HARDENING STEEL – AISI 8620 - continued WELDING: Welding procedure: Readily welded in the as rolled condition with the The use of low hydrogen electrodes correct procedure, but welding in the case recommended. -
Final Exam Questions Generated by the Class
Final Exam Questions Generated by the Class Module 8 – Iron and Steel Describe some of the business practices that Carnegie employed that allowed him to take command of the steel industry. Hard driving, vertical integration, price making Which of the following was/is NOT a method used to make steel? A. Puddling B. Bessemer process C. Basic oxygen process D. Arc melting E. None of the above What are the three forms of iron, and what is the associated carbon content of each? Wrought <.2% Steel .2-2.3% Cast Iron 2.3-4.2% How did Andrew Carnegie use vertical integration to gain control of the steel market? Controlled the entire steel making process from mining to final product Who created the best steel for several hundred years while making swords during the 1500’s? A. Syria B. Egypt C. Japan D. England Describe the difference between forging and casting. When forging, you beat and hammer the material into the desired shape. When casting, you pour liquid into a mold to shape it. Describe the difference between steel and wrought iron. Steel has less carbon Which of the following forms of iron has a low melting point and is not forgeable? A. Steel B. Pig Iron C. Wrought Iron D. None of the Above What two developments ushered in the transition from the Bronze Age to the Iron Age? More iron ore and greater ability to change its properties using readily available alloying agent (carbon) 1 Final Exam Questions Generated by the Class What is the difference between ferrite and austenite? A. -
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. -
Precipitation Hardening of Metal Alloys
Precipitation Hardening of Metal Alloys Precipitation hardening, or age hardening, provides to look; following Merica, new age-hardening alloys one of the most widely used mechanisms for the came in a flood.” strengthening of metal alloys. The fundamental under- The importance of the theoretical suggestion for the standing and basis for this technique was established in development of new alloys is clear from the historical early work at the U. S. Bureau of Standards on an alloy record [5]. At the end of the 19th century, cast iron was known as Duralumin [1,2]. Duralumin is an aluminum the only important commercial alloy not already known alloy containing copper and magnesium with small to western technology at the time of the Romans. When amounts of iron and silicon. In an attempt to understand age hardening of aluminum was discovered accidentally the dramatic strengthening of this alloy, Paul D. Merica by Wilm [6], during the years 1903-1911, it quickly and his coworkers studied both the effect of various heat became an important commercial alloy under the trade treatments on the hardness of the alloy and the influence name Duralumin. of chemical composition on the hardness. Among the The two NBS studies published in 1919 explored both most significant of their findings was the observation the application of phase diagrams to the phenomenon that the solubility of CuAl2 in aluminum increased with and the consequences of various heat treatments on the increasing temperature. Although the specific phases subsequent time evolution of mechanical properties. responsible for the hardening turned out to be too small The latter study tentatively concluded that age harden- to be observed directly, optical examination of the ing of aluminum was a room-temperature precipitation microstructures provided an identification of several of phenomenon and suggested that it should be possible for the other phases that were present. -
Chapter 11: Metal Alloys Applications and Processing
Chapter 11: Metal Alloys Applications and Processing ISSUES TO ADDRESS... • How are metal alloys classified and how are they used? • What are some of the common fabrication techniques? • How do properties vary throughout a piece of material that has been quenched, for example? • How can properties be modified by post heat treatment? Chapter 11 - 1 Taxonomy of Metals Metal Alloys Adapted from Ferrous Nonferrous Fig. 11.1, Callister 7e. SteelsSteels CastCast Irons Irons Cu Al Mg Ti <1.4<1.4wt%Cwt% C 33-4.54.5wt%Cwt% C T(°C) microstructure: 1600 ferrite, graphite δ cementite 1400 L γ+L Adapted from Fig. 9.24,Callister 7e. 1200 (Fig. 9.24 adapted from Binary Alloy γ 1148°C L+Fe3C Phase Diagrams, 2nd ed., austenite Eutectic: 1000 4.30 Vol. 1, T.B. Massalski (Ed.-in-Chief), ASM International, Materials Park, OH, 1990.) γ+Fe3C α800 727°C Fe3C ferrite Eutectoid: cementite 600 0.76 α+Fe3C 400 0 1 2 3 4 5 6 6.7 (Fe) Co , wt% C Chapter 11 - 2 Steels Low Alloy High Alloy low carbon Med carbon high carbon <0.25wt%C 0.25-0.6wt%C 0.6-1.4wt%C heat austenitic Name plain HSLA plain plain tool treatable stainless Cr,V Cr, Ni Cr, V, Additions none none none Cr, Ni, Mo Ni, Mo Mo Mo, W Example 1010 4310 1040 4340 1095 4190 304 Hardenability 0 + + ++ ++ +++ 0 TS - 0 + ++ + ++ 0 EL + + 0 - - -- ++ Uses auto bridges crank pistons wear drills high T struc. towers shafts gears applic. saws applic. sheet press.