Steel: 101 the Making, Shaping and Treating Of
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Wear Behavior of Austempered and Quenched and Tempered Gray Cast Irons Under Similar Hardness
metals Article Wear Behavior of Austempered and Quenched and Tempered Gray Cast Irons under Similar Hardness 1,2 2 2 2, , Bingxu Wang , Xue Han , Gary C. Barber and Yuming Pan * y 1 Faculty of Mechanical Engineering and Automation, Zhejiang Sci-Tech University, Hangzhou 310018, China; [email protected] 2 Automotive Tribology Center, Department of Mechanical Engineering, School of Engineering and Computer Science, Oakland University, Rochester, MI 48309, USA; [email protected] (X.H.); [email protected] (G.C.B.) * Correspondence: [email protected] Current address: 201 N. Squirrel Rd Apt 1204, Auburn Hills, MI 48326, USA. y Received: 14 November 2019; Accepted: 4 December 2019; Published: 8 December 2019 Abstract: In this research, an austempering heat treatment was applied on gray cast iron using various austempering temperatures ranging from 232 ◦C to 371 ◦C and holding times ranging from 1 min to 120 min. The microstructure and hardness were examined using optical microscopy and a Rockwell hardness tester. Rotational ball-on-disk sliding wear tests were carried out to investigate the wear behavior of austempered gray cast iron samples and to compare with conventional quenched and tempered gray cast iron samples under equivalent hardness. For the austempered samples, it was found that acicular ferrite and carbon saturated austenite were formed in the matrix. The ferritic platelets became coarse when increasing the austempering temperature or extending the holding time. Hardness decreased due to a decreasing amount of martensite in the matrix. In wear tests, austempered gray cast iron samples showed slightly higher wear resistance than quenched and tempered samples under similar hardness while using the austempering temperatures of 232 ◦C, 260 ◦C, 288 ◦C, and 316 ◦C and distinctly better wear resistance while using the austempering temperatures of 343 ◦C and 371 ◦C. -
Society, Materials, and the Environment: the Case of Steel
metals Review Society, Materials, and the Environment: The Case of Steel Jean-Pierre Birat IF Steelman, Moselle, 57280 Semécourt, France; [email protected]; Tel.: +333-8751-1117 Received: 1 February 2020; Accepted: 25 February 2020; Published: 2 March 2020 Abstract: This paper reviews the relationship between the production of steel and the environment as it stands today. It deals with raw material issues (availability, scarcity), energy resources, and generation of by-products, i.e., the circular economy, the anthropogenic iron mine, and the energy transition. The paper also deals with emissions to air (dust, Particulate Matter, heavy metals, Persistant Organics Pollutants), water, and soil, i.e., with toxicity, ecotoxicity, epidemiology, and health issues, but also greenhouse gas emissions, i.e., climate change. The loss of biodiversity is also mentioned. All these topics are analyzed with historical hindsight and the present understanding of their physics and chemistry is discussed, stressing areas where knowledge is still lacking. In the face of all these issues, technological solutions were sought to alleviate their effects: many areas are presently satisfactorily handled (the circular economy—a historical’ practice in the case of steel, energy conservation, air/water/soil emissions) and in line with present environmental regulations; on the other hand, there are important hanging issues, such as the generation of mine tailings (and tailings dam failures), the emissions of greenhouse gases (the steel industry plans to become carbon-neutral by 2050, at least in the EU), and the emission of fine PM, which WHO correlates with premature deaths. Moreover, present regulatory levels of emissions will necessarily become much stricter. -
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. -
Crucible A2 Data Sheet
CRUCIBLE DATA SHEET Airkool (AISI A2) is an air-hardening medium alloy tool steel ® Issue #1 which is heat treatable to HRC 60-62. It has wear resistance AIRKOOL intermediate between the oil hardening tool steels (O1) and (AISI A2) the high carbon chromium tool steels (D2). Because it offers a combination of good toughness along with moderate Carbon 1.00% wear resistance, it has been widely used for many years in Manganese 0.85% variety of cold work applications which require fairly high abrasion resistance but where the higher carbon/ high Chromium 5.25% chromium steels are prone to chipping and cracking. Molybdenum 1.10% Airkool is quite easily machined in the annealed condition Vanadium 0.25% and, like other air-hardening tool steels, exhibits minimal distortion on hardening, making it an excellent choice for dies of complicated design. Physical Properties Elastic Modulus 30 X 106 psi (207 GPa) Density 0.284 lbs./in3 (7.86 g/cm3) Thermal Conductivity Tool Steel Comparagraph BTU/hr-ft-°F W/m-°K cal/cm-s-°C at 200°F (95°C) 15 26 0.062 Coefficient of Thermal Expansion ° ° Toughness in/in/ F mm/mm/ C ° ° -6 -6 Wear Resistance 70-500 F (20-260 C) 5.91 X10 (10.6 X10 ) 70-800°F (20-425°C) 7.19 X10-6 (12.9 X10-6) 70-1000°F (20-540°C) 7.76 X10-6 (14.0 X10-6) 70-1200°F (20-650°C) 7.91 X10-6 (14.2 X10-6) Relative Values Mechanical Properties Heat Treatment(1) Impact Wear Austenitizing Toughness(2) Resistance(3) Temperature HRC ft.-lb. -
Improving the Corrosion Behavior of Ductile Cast Iron in Sulphuric Acid
Available online at www.pelagiaresearchlibrary.com Pelagia Research Library Der Chemica Sinica, 2017, 8(6):513-523 ISSN : 0976-8505 CODEN (USA): CSHIA5 Improving the Corrosion Behavior of Ductile Cast Iron in Sulphuric Acid by Heat Treatment TFH Mohamed, SS Abd El Rehim and MAM Ibrahim* Chemistry Department, Faculty of Science, Ain Shams University, Abbassia, Cairo, Egypt ABSTRACT In this investigation, the effect of heat treatment on the corrosion behavior of ductile cast iron (DCI) in H2SO4 environment has been conducted. Moreover, the effect of heat treatment on the mechanical properties has also been investigated. The change in microstructure of DCI is obtained by austenetising at 900°C for two hours followed by oil quenching and then heated to 700ºC for different tempering times. The corrosion measurements were tested using anodic potentiodynamic polarization and cyclic polarization techniques. Here we show that the tempered specimens at different tempering times show better corrosion resistance in H2SO4 solution than that without heat treatment. Moreover, the polarization measurements showed that the Ecorr and ia of the different specimens increase with increasing H2SO4 concentration while both Epass and ipass were decreased. Keywords: Ductile cast iron, Corrosion behaviour, Potentiodynamic, Cyclic polarization, Heat treatment INTRODUCTION Ductile cast iron (DCI) possesses several engineering and manufacturing advantages when compared with cast steels [1,2]. These include an excellent damping capacity, better wear resistance, 20-40% lower manufacturing cost and lower volume shrinkage during solidification [3,4]. The combination between the good mechanical properties and the casting abilities of DCI makes its usage successful in structural applications especially in the automotive industry. -
Electric Furnace Steelmaking
CHAPTER 1.5 Electric Furnace Steelmaking Jorge Madias Metallon, Buenos Aires, Argentina 1.5.1. INTRODUCTION TO ELECTRIC STEELMAKING The history of electric steelmaking is quite short—only little over 100 years from the first trials to melt steel by utilizing electric power. During that period, great advance- ments have been attained both in furnace equipment and technology, melting practice, raw materials, and products. In this chapter, a short introduction to most significant pro- gresses, features, and phenomena in electric steelmaking are presented. 1.5.1.1. Short History of Electric Steelmaking Until Today The electric arc furnace applied in steelmaking was invented in 1889 by Paul He´roult [1]. Emerging new technology started in the beginning of the twentieth century when wide- ranging generation of relatively cheap electric energy started at that time. First-generation furnaces had a capacity in between 1 and 15 t. The EAF had Bessemer/Thomas converters and Siemens Martin furnaces as strong competitors, initially. But its niche was the produc- tion of special steels requiring high temperature, ferroalloy melting, and long refining times. In the 1960s, with the advent of billet casting, the EAF occupied another niche: it was the melting unit of choice for the so-called minimills, feeding billet casters for the pro- duction of rebar and wire rod. In the following two decades, to better support the short tap-to-tap time required by the billet casters, the EAF reinvented itself as a melting-only unit. Steel refining was left for the recently introduced ladle furnace. Large transformers were introduced; ultra- high-power furnaces developed, which were made possible by adopting foaming slag practice. -
The Effect of Tempering on the Microstructure and Mechanical
applied sciences Article The Effect of Tempering on the Microstructure and Mechanical Properties of a Novel 0.4C Press-Hardening Steel Oskari Haiko 1,* , Antti Kaijalainen 1 , Sakari Pallaspuro 1 , Jaakko Hannula 1, David Porter 1, Tommi Liimatainen 2 and Jukka Kömi 1 1 Materials and Mechanical Engineering, Centre for Advanced Steels Research, University of Oulu, 90014 Oulu, Finland; antti.kaijalainen@oulu.fi (A.K.); sakari.pallaspuro@oulu.fi (S.P.); jaakko.hannula@oulu.fi (J.H.); david.porter@oulu.fi (D.P.); jukka.komi@oulu.fi (J.K.) 2 Raahe Works, SSAB Europe, 92100 Raahe, Finland; [email protected] * Correspondence: oskari.haiko@oulu.fi Received: 12 September 2019; Accepted: 4 October 2019; Published: 10 October 2019 Featured Application: Potential wear-resistant steel for harsh environments in agricultural sector, i.e., chisel ploughs and disc harrows. Abstract: In this paper, the effects of different tempering temperatures on a recently developed ultrahigh-strength steel with 0.4 wt.% carbon content were studied. The steel is designed to be used in press-hardening for different wear applications, which require high surface hardness (650 HV/58 HRC). Hot-rolled steel sheet from a hot strip mill was austenitized, water quenched and subjected to 2-h tempering at different temperatures ranging from 150 ◦C to 400 ◦C. Mechanical properties, microstructure, dislocation densities, and fracture surfaces of the steels were characterized. Tensile strength greater than 2200 MPa and hardness above 650 HV/58 HRC were measured for the as-quenched variant. Tempering decreased the tensile strength and hardness, but yield strength increased with low-temperature tempering (150 ◦C and 200 ◦C). -
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. -
BAT Guide for Electric Arc Furnace Iron & Steel Installations
Eşleştirme Projesi TR 08 IB EN 03 IPPC – Entegre Kirlilik Önleme ve Kontrol T.C. Çevre ve Şehircilik Bakanlığı BAT Guide for electric arc furnace iron & steel installations Project TR-2008-IB-EN-03 Mission no: 2.1.4.c.3 Prepared by: Jesús Ángel Ocio Hipólito Bilbao José Luis Gayo Nikolás García Cesar Seoánez Iron & Steel Producers Association Serhat Karadayı (Asil Çelik Sanayi ve Ticaret A.Ş.) Muzaffer Demir Mehmet Yayla Yavuz Yücekutlu Dinçer Karadavut Betül Keskin Çatal Zerrin Leblebici Ece Tok Şaziye Savaş Özlem Gülay Önder Gürpınar October 2012 1 Eşleştirme Projesi TR 08 IB EN 03 IPPC – Entegre Kirlilik Önleme ve Kontrol T.C. Çevre ve Şehircilik Bakanlığı Contents 0 FOREWORD ............................................................................................................................ 12 1 INTRODUCTION. ..................................................................................................................... 14 1.1 IMPLEMENTATION OF THE DIRECTIVE ON INDUSTRIAL EMISSIONS IN THE SECTOR OF STEEL PRODUCTION IN ELECTRIC ARC FURNACE ................................................................................. 14 1.2 OVERVIEW OF THE SITUATION OF THE SECTOR IN TURKEY ...................................................... 14 1.2.1 Current Situation ............................................................................................................ 14 1.2.2 Iron and Steel Production Processes............................................................................... 17 1.2.3 The Role Of Steel Sector in -
187 Gas Nitriding with Deep Cryogenic Treatment Of
Acta Metallurgica Slovaca, Vol. 24, 2018, No. 2, p. 187-193 187 GAS NITRIDING WITH DEEP CRYOGENIC TREATMENT OF HIGH-SPEED STEEL David Hradil1)*, Michal Duchek1), Taťána Hrbáčková1), Aleksander Ciski2) 1) COMTES FHT, Dobřany, Czech Republic 2) Institute of Precision Mechanics, Warsaw, Poland Received: 12.03.2018 Accepted: 28.05.2018 *Corresponding author: e-mail: [email protected], Tel.:+420 377 197 365, COMTES FHT, Průmyslová 995, 334 41 Dobřany, Czech Republic Abstract Nitriding with subsequent heat treatment in combination with deep cryogenic treatment (DCT) produces nitrided layers with specific properties. Layers with unique properties result from the dissolution of subsurface layers of iron nitrides and subsequent nitrogen diffusion into the substrate during austenitisation. Fine precipitates of carbonitrides eventually form during DCT and tempering. Intermediate deep cryogenic treatment was performed between the quenching and tempering steps. This work is based on comparing nitrided layers obtained using conventional treatment parameters with nitrided layers from novel processes. The experimental material was DIN 1.3343 (Czech Standard 41 9830) high-speed steel. Several treatment methods were compared in terms of the resulting hardness and metallographic characteristics. Keywords: Deep Cryogenic Treatment, Nitriding, Metallography, Hardness 1 Introduction Steels are nitrided in the machinery and toolmaking industries to obtain better tribological properties and fatigue performance, which result from compressive stresses generated in the surface [1, 2, 3]. Typical nitrided products include a variety of cutting tools, drills, dies, injection moulds, valves and many machine parts, such as gears, crankshafts and spring [4]. In nitriding, nitrogen is introduced into the surface of steel over a period of several tens of hours. -
Iron and Steel: Introduction
Iron and Steel: Introduction Iron is cheap and strong and the most used metal in the world. Iron, as produced in the blast furnace is called pig iron. This is brittle because it contains about 4% carbon and other non-metal impurities. Most of this iron is converted into a variety of steels by removing nearly all the carbon, and adding small quantities of different metals. The different steels are alloys which are mixtures of metals. They have different properties such as toughness, hardness, corrosion resistance, etc. Some background The method of using carbon to reduce iron oxide to iron was very probably discovered accidentally in prehistoric camp fires. Here, charcoal would have been the source of carbon. The iron was used to make tools and weapons and gave its name to the Iron Age. Early in the 18th century, Abraham Darby in Shropshire discovered a method of converting coal to coke as a source of carbon. This led to the modern blast furnace. In the mid-19th century, Henry Bessemer developed a steel-making process that used oxygen to burn off some of the carbon in cast iron. The Basic Oxygen Steelmaking process was introduced in the 1950s and now accounts for about two-thirds of steel production. Did you know? Stainless steel contains about 18% chromium. About three-quarters of food and drinks cans are made of steel. A car tyre contains over ½ kg of steel wire. About 400 million tonnes of steel are recycled every year worldwide. Iron and Steel: Introduction | 1 . -
ARCHAEOLOGY DATASHEET 302 Steelmaking
ARCHAEOLOGY DATASHEET 302 Steelmaking Introduction A single forging produced ‘shear steel’, a second operation Although an important aspect of medieval and earlier resulted in ‘double shear steel’ and so-on. societies, the manufacture of steel was industrialised during Furnace design changed over time, and also appears to the post-medieval period. Many complementary techniques have shown some regional variation. The first English steel were developed which often operated at the same time on furnaces were built at Coalbrookdale (Shropshire) by Sir the same site; there were also close links with other Basil Brooke in c1615 and c1630. These were circular in ironworking processes. This datasheet describes pre-20th plan with a central flue. They probably contained a single century steelmaking processes in the UK, their material chest and would have had a conical chimney. Other 17th- remains and metallurgical potential. century cementation furnaces were located in and around Birmingham, Wolverhampton, Stourbridge and Bristol, but Carbon steel and other alloys none of these have been excavated. The north-east became Until the late 19th century, steel was, like other types of the main area of cementation steelmaking in the late 17th iron, simply an alloy of iron and carbon (HMS datasheet and early 18th centuries. Ambrose Crowley established 201). There was considerable variation in the nature of several cementation steelworks, and others followed. Of ‘steel’ and in the properties of individual artefacts. Cast these, the oldest standing structure is at Derwentcote iron, smelted in the blast furnace usually had a carbon (County Durham), built in 1734. Unlike the West Midlands content of 5-8%, making it tough but brittle.