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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. -
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. -
ITP Metal Casting: Advanced Melting Technologies
Advanced Melting Technologies: Energy Saving Concepts and Opportunities for the Metal Casting Industry November 2005 BCS, Incorporated 5550 Sterrett Place, Suite 306 Columbia, MD 21044 www.bcs-hq.com Advanced Melting Technologies: Energy Saving Concepts and Opportunities for the Metal Casting Industry Prepared for ITP Metal Casting by BCS, Incorporated November 2005 Acknowledgments This study was a collaborative effort by a team of researchers from University of Missouri–Rolla, Case Western Reserve University, and Carnegie Mellon University with BCS, Incorporated as the project coordinator and lead. The research findings for the nonferrous casting industry were contributed by Dr. Jack Wallace and Dr. David Schwam, while the ferrous melting technologies were addressed by Dr. Kent Peaslee and Dr. Richard Fruehan. BCS, Incorporated researched independently to provide an overview of the melting process and the U.S. metal casting industry. The final report was prepared by Robert D. Naranjo, Ji-Yea Kwon, Rajita Majumdar, and William T. Choate of BCS, Incorporated. We also gratefully acknowledge the support of the U.S. Department of Energy and Cast Metal Coalition (CMC) in conducting this study. Disclaimer This report was prepared as an account of work sponsored by an Agency of the United States Government. Neither the United States Government nor any Agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any Agency thereof. -
Development of Low-Cost Casting Titanium Alloys: an Integrated Computational
Development of Low-cost Casting Titanium Alloys: An Integrated Computational Materials Engineering (ICME) Guided Study Dissertation Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Zhi Liang Graduate Program in Materials Science and Engineering The Ohio State University 2018 Dissertation Committee Professor Alan A. Luo, Advisor Professor Glenn Daehn Professor Ji-cheng Zhao Copyrighted by Zhi Liang 2018 Abstract Titanium alloys have proved to be important lightweight structural materials since 1960’s, due to their excellent intermediate temperature mechanical properties, corrosion resistance and weldability. Their good property-to-weight ratios make them ideal for many high-end and weight-sensitive applications. However, the application of titanium alloys is still limited due to the high costs in raw materials and manufacturing, indicating the importance of developing new cost-effective titanium alloys. Compared with other lightweight structural alloys (e.g. aluminum, magnesium), the raw material cost for titanium alloys is generally considered as expensive due to its expensive alloying elements such as vanadium, molybdenum, and tin. The cost issue is further amplified by the difficulties in using conventional machining methods for component-shaping due to the low thermal conductivity. Therefore, cost-effective titanium alloys should address either aspect. This work focuses on the goal of developing new cost-effective Ti-Al-Fe- Mn titanium alloys for the casting process via Integrated Computational Materials Engineering (ICME) approach by using cheaper alloying elements and net-shape manufacture process. Calculation of Phase Diagram (CALPHAD) work on the Ti-Al-Mn ternary system was conducted to establish the reliable thermodynamic database to guide the alloy design. -
Effect of Compound Jacketing Rolling on Microstructure and Mechanical
EFFECT OF COMPOUND JACKETING ROLLING ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF SUPERALLOY GH4720Li Jinglong Qu 1, Minqing Wang 1, Jianxin Dong 2, Guilin Wu 3, Ji Zhang 1 1 Central Iron and Steel Research Institute, Superalloy Department, No.76, Xueyuan Nanlu, Beijing, 100081, China 2 University of Science and Technology Beijing, Department of Materials Science and Technology, No.30, Xueyuan Lu, Beijing, 100083,China 3 Northeast Special Steel Group Co., Ltd., Liaoning Fushun, 113001, China Keywords: GH4720Li Alloy, Compound Jacketed Rolling, Microstructure, γ′ phase Abstract In this paper, a compound jacketed rolling technique for superalloy GH4720Li is experimentally investigated. The results show that microstructure of GH4720Li is susceptible to hot working parameters. When rolling temperature is about 1130ºC, a fine-grained microstructure, excellent mechanical properties and high yield strength can be obtained. In addition, the rolling temperature can be controlled effectively, friction force between ingot and roller can be reduced, surface cracking induced by rolling can be avoided, and uniform microstructure can be obtained using compound jacketing. When accumulative strain of rolling is greater than 65%, the coarse columnar dendritic microstructure can be refined completely and grain size of ASTM 8 obtained. After heat treatment, GH4720Li bars exhibit excellent mechanical properties. Introduction GH4720Li is a high strength and difficult-to-deform superalloy with excellent mechanical, corrosion resistant and oxidation resistant properties. It is now widely used in aircraft and land-based turbine discs. In practice, the temperature required for a long-term use of GH4720Li is below 700 °C. The weight percent of Al+Ti is as high as 7.5%, and the amount of γ′ strengthening phase is as high as 40%. -
Effect of Melting Process and Aluminium Content on the Microstructure and Mechanical Properties of Fe–Al Alloys
ISIJ International, Vol. 50 (2010), No. 10, pp. 1483–1487 Effect of Melting Process and Aluminium Content on the Microstructure and Mechanical Properties of Fe–Al Alloys Shivkumar KHAPLE, R. G. BALIGIDAD, M. SANKAR and V. V. Satya PRASAD Defence Metallurgical Research Laboratory, Kanchanbagh, Hyderabad, 500058 India. E-mail: [email protected] (Received on January 4, 2010; accepted on July 1, 2010) This paper presents the effect of air induction melting with flux cover (AIMFC) versus vacuum induction melting (VIM) on the recovery of alloying element, reduction of impurities, workability and mechanical prop- erties of Fe–(7–16mass%)Al alloys. Three Fe–Al alloy ingots containing 7, 9 and 16 mass% Al were prepared by both AIMFC and VIM. All these ingots were hot-forged and hot-rolled at 1 373 K and were further charac- terized with respect to chemical composition, microstructure and mechanical properties. The recovery of aluminium as well as reduction of oxygen during both AIMFC and VIM is excellent. AIMFC ingots exhibit low level of sulphur and high concentration of hydrogen as compared to VIM ingots. VIM ingots of all the three alloys were successfully hot worked. However, AIMFC ingots of only those Fe–Al alloys containing lower concentration of aluminium could be hot worked. The tensile properties of hot-rolled Fe–7mass%Al alloy produced by AIMFC and VIM are comparable. The present study clearly demonstrates that it is feasible to produce sound ingots of low carbon Fe–7mass%Al alloy by AIMFC process with properties comparable to the alloy produced by VIM. KEY WORDS: air inducting melting with flux cover; vacuum induction melting; Fe–Al alloy; microstructure; mechanical properties. -
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 -
Primary Mill Fabrication
Metals Fabrication—Understanding the Basics Copyright © 2013 ASM International® F.C. Campbell, editor All rights reserved www.asminternational.org CHAPTER 1 Primary Mill Fabrication A GENERAL DIAGRAM for the production of steel from raw materials to finished mill products is shown in Fig. 1. Steel production starts with the reduction of ore in a blast furnace into pig iron. Because pig iron is rather impure and contains carbon in the range of 3 to 4.5 wt%, it must be further refined in either a basic oxygen or an electric arc furnace to produce steel that usually has a carbon content of less than 1 wt%. After the pig iron has been reduced to steel, it is cast into ingots or continuously cast into slabs. Cast steels are then hot worked to improve homogeneity, refine the as-cast microstructure, and fabricate desired product shapes. After initial hot rolling operations, semifinished products are worked by hot rolling, cold rolling, forging, extruding, or drawing. Some steels are used in the hot rolled condition, while others are heat treated to obtain specific properties. However, the great majority of plain carbon steel prod- ucts are low-carbon (<0.30 wt% C) steels that are used in the annealed condition. Medium-carbon (0.30 to 0.60 wt% C) and high-carbon (0.60 to 1.00 wt% C) steels are often quenched and tempered to provide higher strengths and hardness. Ironmaking The first step in making steel from iron ore is to make iron by chemically reducing the ore (iron oxide) with carbon, in the form of coke, according to the general equation: Fe2O3 + 3CO Æ 2Fe + 3CO2 (Eq 1) The ironmaking reaction takes place in a blast furnace, shown schemati- cally in Fig. -
Simulation of Intrinsic Inclusion Motion and Dissolution During the Vacuum Arc Remelting of Nickel Based Superalloys W
SIMULATION OF INTRINSIC INCLUSION MOTION AND DISSOLUTION DURING THE VACUUM ARC REMELTING OF NICKEL BASED SUPERALLOYS W. Zhang, P.D. Lee and M. McLean Department of Materials, Imperial College London SW7 2BP, UK R.J. Siddall Special Metals Limited, Wiggin Works, Holmer Road Hereford HR4 9SL, UK dissolution of intrinsic particles for typical melt conditions of Abstract INCONEL 7 18’. Vacuum Arc Remelting (VAR) is one of the state-of-the-art Introduction secondaryre-melting processesthat are now routinely used to improve the homogeneity, purity and defect concentration in The VAR process has been investigated previously by both modern turbine disc alloys. The last is of particular importance experimental and mathematicaltechniques. Early mathematical since, as the yield strength of turbine disc alloys has approachessolved for heat transfer and approximated the fluid progressively increasedto accommodateincreasingly stringent flow by using an enhancedthermal conductivity in the molten design requirements, the fracture of these materials has region [l]. The next stage of modeling complexity become sensitive to the presence of ever smaller defects, incorporated the fluid flow using a quasi-steady state particularly inclusions. During the manufacture of these alloys assumption [2,3]. More recently Jardy et al. [4] presented a extrinsic defects can be introduced in the primary alloy model that simulated the transient growth of the ingot and production stage from a variety of sources; these include macrosegregation.In the last few years some authors have ceramic particles originating from crucibles, undissolved used macromodelsto investigate how the formation of defects tungsten (or tungsten carbide) and steel shot. In addition such as freckles correlated to operational parameters[.5,6]. -
Historic Lighthouse Preservation: IRON WPTC Photo Figure 1
Historic Lighthouse Preservation: IRON WPTC photo Figure 1. Cast-iron-and-steel skeletal 191-foot-tall tower at Cape Charles, Virginia Second to masonry, iron was the most Iron was also used for the production of common lighthouse construction material. architectural trim features such as gallery For lighthouse construction, iron was used deck brackets, entryway pilasters and in a variety of its commercially pediments, doors, and prefabricated lantern manufactured alloys: wrought iron, cast components. These iron features were used iron, steel, galvanized iron and steel, and on masonry and wood as well as iron stainless steel. In historic lighthouses the lighthouses. Other iron alloys such as steel, most widely used alloy was cast iron. The galvanized iron and steel, and stainless steel use of cast iron in lighthouse construction are mostly found in modern additions such ranged from simple prefabricated lanterns as handrails, equipment brackets, security to caisson-style foundations to 190-foot-tall doors, etc. first-order coastal towers. For more on the This section will discuss the preservation of variety of iron lighthouse construction types iron alloys used in lighthouse tower refer to Part II., History of the Lighthouse construction and decoration. Because of Service and Lighthouse Construction their similar properties, the various iron Types. alloys will be discussed together; special treatments concerning a specific alloy will Historic Lighthouse Preservation Handbook Part IV. B, Page 1 WPTC photo Figure 2. Example of a keeper's quarters fitted with a prefabricated cast-iron-and-steel lantern. WPTC photo Figure 4. Double-wall, cast-iron, first-order 163-foot-tall WPTC photo coastal tower at Cape Henry, Virginia. -
The Importance of Sic in the Process of Melting Ductile Iron with a Variable Content of Charge Materials
materials Article The Importance of SiC in the Process of Melting Ductile Iron with a Variable Content of Charge Materials Krzysztof Janerka 1 , Łukasz Kostrzewski 2, Marcin Stawarz 1 and Jan Jezierski 1,* 1 Department of Foundry Engineering, Silesian University of Technology, 7 Towarowa, 44-100 Gliwice, Poland; [email protected] (K.J.); [email protected] (M.S.) 2 LFP Ltd., 15 Fabryczna, 64-100 Leszno, Poland; [email protected] * Correspondence: [email protected]; Tel.: +48-32-338-5551 Received: 15 February 2020; Accepted: 6 March 2020; Published: 9 March 2020 Abstract: The article presents issues related to melting ductile iron grade EN-GJS-400-15, with different proportions of feedstock (steel scrap and pig iron). The main attention was paid to determining the impact of silicon carbide on the structure and properties of melted cast iron. In the conducted melts, carbon and silicon deficiencies were supplemented with a suitably chosen carburizer, ferrosilicon, and SiC metallurgical silicon carbide. The percentage of silicon carbide in the charge ranged from 0 to 0.91%. The basic condition for the planning of melts was to maintain the repeatability of the chemical composition of the output cast iron and cast iron after the secondary treatment of liquid metal with various charge compositions. Based on the tests, calculations, and analyses of the results obtained, it was concluded that the addition of SiC may increase the number and size of graphite precipitates. Increasing the SiC content in the charge also caused a change in the solidification nature of the alloy and the mechanism of growth of spheroidal graphite precipitates, causing their surface to form a scaly shell. -
Solidification of Alloy 718 During Vacuum Arc Remelting with Helium
SOLIDIFICATION OF ALLOY 718 DURING VACUUMARC REMELTING WITH HELIUM GAS COOLING BETWEEN INGOT AND CRUCIBLE L. G. Hosamani, W. E. Wood* and J. H. Devletian* Precision Castparts Corp., Portland, Oregon * Department of Materials Science and Engineering Oregon Graduate Center Beaverton, Oregon Abstract There is an increased demand for larger and better-quality vacuum arc melted superalloy ingots. However, as the ingot size increases, the ten- dency for segregation increases. The segregation can be minimized either by decreasing the melt rate or by improving the heat transfer from the ingot. The former technique results in decreased productivity and in- creased energy consumption during melting. The heat transfer from the ingot to the cooling water in VAR is mainly controlled by the heat transfer coefficient between the ingot and crucible. This heat transfer coefficient can be increased by introducing a gas of high thermal conductivity, like helium, in the shrinkage gap between the ingot and crucible. Even though this technique is being used by superalloys manufacturers, no systematic study has been carried out to quantify the effect of helium gas pressure. Hence, the present experimental work was undertaken to study the effect of helium gas cooling on the heat extraction rate, molten metal pool depth, mushy zone size and segregation during vacuum arc remelting of alloy 718. The experiments were carried out in a laboratory vacuum arc furnace capable of making 210 mm diameter ingots weighing up to 150 kgs. In this paper, the effect of helium gas pressure on the solidification behavior of alloy 718, like molten metal pool depth, surface quality of the ingot, dendrite arm spacing, mushy zone size and Laves phase, have been discussed.