Inclusions Properties at 1673 K and Room Temperature with Ce Addition
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Thermodynamics of Titanium Oxide in Ladle Slags
ISIJ International, Vol. 41 (2001), No. 12, pp. 1447–1453 Thermodynamics of Titanium Oxide in Ladle Slags Sung-Mo JUNG and R. J. FRUEHAN1) Formerly Postdoctoral research associate, at Department of Materials Science and Engineering, Carnegie Mellon University, now at Graduate School of Iron and Steel Technology, Pohang University of Science and Technology, Pohang 790-784, Korea. 1) Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, PA 15213 USA. (Received on May 17, 2001; accepted in final form on August 27, 2001) It is necessary to have information on the thermodynamic behavior of titanium oxide in ladle type slags in order to control the titanium content in several grades of steel. In the present study, the thermodynamics was determined from the equilibrium between Fe–Csat–Ti and CaO–SiO2-–30%Al2O3–MgO–TiOx slags , in equilibrium with CO and from the equilibrium between Fe–Csat–(16 18)%Cr–Si–Ti and CaO–SiO2– 20%Al2O3–MgO–TiOx slags in equilibrium with CO. From the experiment with Fe–Csat–Ti alloy, the activity coefficients of TiO1.5 and TiO2 vary with basicity from 0.3 to 1.5 and from 0.5 to 2.3, respectively. And from , the experiment with Fe–Csat–(16 18)%Cr–Si–Ti alloy, the activity coefficients of TiO1.5 and TiO2 vary with ba- sicity from 0.4 to 1.4 and from 0.6 to 3.5, respectively. The results obtained from the equilibrium between , Fe–Csat–(16 18)%Cr–Si–Ti and CaO-SiO2–20%Al2O3–MgO–TiOx slags were used to estimate the titanium content of silicon-added stainless steel. -
ARCHIVES of FOUNDRY ENGINEERING Volume 18, Issue 1/2018, 129 - 1 3 4 During Electrolytic Dissolution
ARCHIVES ISSN (2299-2944) Volume 18 of Issue 1/2018 FOUNDRY ENGINEERING 129 – 134 DOI: 10.24425/118825 24/1 Published quarterly as the organ of the Foundry Commission of the Polish Academy of Sciences A Study of Inclusions in Aluminum and Titanium Deoxidized 4130 R.B. Tuttle *, S. Kottala Saginaw Valley State University, 209 Pioneer Hall, 7400 Bay Rd., 48710 University Center, United States * Corresponding author. E-mail address: [email protected] Received 02.10.2017; accepted in revised form 14.11.2017 Abstract In this paper, the authors investigated the size distribution of titanium oxide (TiO2), titanium nitride (TiN) and titanium carbide (TiC) inclusions in a titanium deoxidized 4130 steel and compared it with the 4130 base alloy composition inclusions. TiN and TiC inclusions are of particular interest due to their role as heterogeneous nuclei for various phase reactions in steels. Two types of samples were prepared, a polished sample and a filtered sample. Electrolytic dissolution was employed to make the filter paper samples. The size range of titanium inclusions was found to be more than that of the non-metallic inclusions from 4130 base alloy heat. Titanium inclusions from the filter and polished samples were round in shape. TiC and TiN inclusions were not found in the electrolytic extraction samples. Inclusions and their chemistries were analyzed using scanning electron microscope and energy dispersive spectrometer. The inclusion size range was larger for the titanium deoxidized samples than the base alloy. However, in both steels the majority of inclusions had a size smaller than 10 μm. Keywords: Steel, Sand casting, Inclusions, Electrolytic extraction, Inclusion characterization 1. -
Effect of Deoxidation Sequence on Carbon Manganese Steel Weld Metal Microstructures
Effect of Deoxidation Sequence on Carbon Manganese Steel Weld Metal Microstructures Deoxidation sequence has a strong influence on nonmetallic inclusions formation and the subsequent weld refinement BY F-C. LIAO AND S. LIU ABSTRACT. During investigation of indi boundary ferrite and Widmanstatten side the molten metal for the purpose of vidual and combined effects of aluminum plate ferrite are often grouped together as deoxidation. Some common deoxidizers and titanium on low-carbon low-alloy primary ferrite (PF). As the weld tempera used in steel making are aluminum, silicon, steel weld metal microstructures, experi ture continues to drop, fine acicular ferrite manganese, and titanium. In arc welding, mental welds were made on 12.7-mm (AF) laths begin to nucleate intragranularly. these same elements are also used for (0.5-in.) thick A516 C70 pressure vessel Finally, the remaining austenite transforms weld pool deoxidation and alloying. They steel plates using ER70S-3 welding wire to a variety of microstructural features, enter the weld pool from the base metal, and a low-oxygen potential commercial which include bainite (B), martensite (M) electrode, or fluxes. In ladle refining of flux. In the aluminum or titanium (individ and pearlite (P). Together with the re steels, the deoxidation reactions occur at ual) addition series welds, the results indi tained austenite, martensite and carbides near isothermal and equilibrium condi cated that the final weld metal microstruc form the microconstituents known as tions quite different from those found in tures are related to the inclusion size dis MAC. The relative proportions of the dif most welding conditions. -
The Role of Alloying Elements on the Fabricability of Austenitic Stainless Steel
The Role of Alloying Elements on the Fabricability of Austenitic Stainless Steel John C. Tverberg, P.E. Metals and Materials Consulting Engineers Mukwonago, Wisconsin How many times have fabrication problems developed when a new coil or a new heat of steel is put in production? The problems can be tearing, cracking, scratching, poorer weld penetration, poor electropolished surface or a host of other problems. The usual procedure to determine the source of the problem is a hardness test, tensile test, and metallographic cross section and to review the mill test reports. Sometimes the source of the problem is spotted, but most often nothing out of the ordinary is found. In these cases the problem lies in the composition of the steel even when the alloy is within the specified composition of the steel. Alloy Design Austenitic stainless steels are designed to give corrosion resistance in many environments, resistance to hydrogen and 885º F (475º C) embrittlement, good strength, good ductility and low hardness. In its simplest form stainless steel is iron with 12% minimum chromium. This is what makes stainless steel rust resistant and allows the passive film to develop. Stainless steel exists in three metallurgical conditions depending on composition and heat treatment: ferritic, martensitic and austenitic. These names refer to the crystallographic structure: ferrite is body-centered cubic, austenite is face-centered cubic and martensite is a distorted tetragonal which is the distorted face-centered cubic structure being changed into a body-centered structure. The characteristics of these structures are tabulated in Table I and are illustrated in Figure 1. -
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. -
The Role of Zirconium in Microalloyed Steels
The Role of Zirconium in Microalloyed Steels T N Baker Department of Mechanical and Aerospace Engineering The University of Strathclyde, Glasgow G1 1XJ, UK. E-mail:[email protected]. Abstract Recently there has been a renewed interest in the addition of zirconium to microalloyed steels. It has been used since the early 1920’s, but has never been universally employed, as have niobium, titanium or vanadium. The functions of zirconium in steelmaking are associated with a strong chemical affinity, in decreasing order, for oxygen, nitrogen, sulphur and carbon. Historically, the main use of additions of zirconium to steel was for combination preferentially with sulphur and so avoid the formation of manganese sulphide, known to have a deleterious influence of the impact toughness of wrought and welded steel. Modern steelmaking techniques have also raised the possibility that zirconium additions can reduce the austenite grain size and increase dispersion strengthening, due to precipitation of zirconium carbonitrides, or in high nitrogen vanadium-zirconium steels, vanadium nitride. This review gathers information on the compounds of zirconium identified in steels together with crystallographic data and solubility equations. Also brief accounts of the role of sulphides and particles in general on austenite grain size control and toughness are included. Keywords: Zirconium compounds, mechanical properties, impact, microstructure 1 1 Introduction The term microalloying, as applied to steels, is generally accepted as emanating from the paper by Beiser1 published in 1959, which reported the results of small additions of niobium to commercial heats of a carbon steel. However, it has not been recognized that microalloying as such, first occurred some 35 years earlier, when small additions of zirconium were added to plain carbon steels, and the effects reported by Feild2 and by Beckett3. -
Refractory Coatings for Containment of Molten Reactive Metals and Their Alloys
REFRACTORY COATINGS FOR CONTAINMENT OF MOLTEN REACTIVE METALS AND THEIR ALLOYS Hui Su B.E. Northeast University of Technology, Shenyang, China, 1984 M.E. Northeast University of Technology, Shenyang, China, 1987 A dissertation submitted to the faculty of the Oregon Graduate Institute of Science & Technology in partial fulfillment of the requirements for the degree Doctor of Philosophy in Materials Science October 1996 The Dissertation "Refractory Coatings for Containment of Molten Reactive Metals and Their Alloys" by Hui Su has been examined and approved by following Examination Committee: Milton R. Scholl, ~hesisAdvisor Assistant Professor James T. ~tanle~;~hesi;p".&r . President, Material Soft ,& David G. Atteridge Professor - - Jack H. Devletian Professor ACKNOWLEDGMENT I would like to express my sincerest appreciation to my thesis advisors, Dr. Milton Scholl and Dr. James T. Stanley, for their guidance, support and patience through this work. I also wish to thank the other members of my dissertation committee, Dr. David Atteridge and Dr. Jack H. Devletian for their time and effort spent as committee members and examining my dissertation and sharing their professional opinions. I am grateful to Dr. Don Mc Murchie for his invaluable help in the plasma spraying laboratory. I would also like to acknowledge Dr. Jack Mccarthy and Mr. Steven Brooks for their help and cooperation in SEM and TEM analysis and melting experiments. I would like to express my appreciation to Dr. Paul Clayton, my four year SPC chairman, for his invaluable advice and help in my course curriculum. I also would like to thank Department Head Dr. Bill Wood for his help, especially for the final year financial support. -
Effective Method for Preparing Low-Oxygen Titanium Ingot By
[Research Paper] 대한금속 · 재료학회지 (Korean J. Met. Mater.), Vol. 59, No. 3 (2021) pp.149-154 DOI: 10.3365/KJMM.2021.59.3.149 Effective Method for Preparing Low-Oxygen Titanium Ingot by Combined Powder Deoxidation and Vacuum Arc Melting Processes Jung-Min Oh1, Jaeyeol Yang2, Jaesik Yoon2, and Jae-Won Lim1,* 1Division of Advanced Materials Engineering and Research Center for Advanced Materials Development, College of Engineering, Jeonbuk National University, Jeonju 54896, Republic of Korea 2Division of Earth and Environmental Science, Korea Basic Science Institute, Cheongju 28119, Republic of Korea Abstract: In this study, an effective method is demonstrated for fabricating titanium sputtering targets, which are used to fabricate thin films in the semiconductor industry. The method is an alternative to the existing electron beam melting (EBM) process under high vacuum. Titanium sputtering targets used in the production of semiconductors must have very low concentrations of gaseous impurities, especially oxygen, as well as metal impurities. Currently, the oxygen concentration in titanium sputtering targets used for industrial purposes is less than 400 ppm. To develop an effective alternative method, powder metallurgy and melting processes were performed to prepare a low-oxygen titanium ingot with less than 400 ppm oxygen. First, titanium powder was deoxidized using calcium vapor, and then the powder was subjected to vacuum arc melting (VAM). The oxygen in the titanium powder was reduced with calcium vapor from an initial concentration of 2200 ppm to 800 ppm, and the resulting powder was melted using VAM, resulting in titanium ingots with low oxygen content, 400 ppm or less. It was also confirmed that all lattice constants, i.e., d, a, c, and c/a, decreased as oxygen concentration decreased in both the titanium powder and the ingots. -
Yields of Rare Earths in the Process of Smelting Steels by Magnesia Crucible
Advances in Engineering Research, volume 120 International Forum on Energy, Environment Science and Materials (IFEESM 2017) Yields of rare earths in the process of smelting steels by magnesia crucible Ya-Bo Li 1,2, a, Ji-Peng Zhao 2,b and Shao-kang Liu3,c 1School of Materials Science and Engineering, Jiangsu University, Zhenjiang, China 2 Tongyu Heavy Industry Co., Ltd., Yucheng, China 3Jiangsu Yonggang Group Co., Ltd, Zhangjiagang, China [email protected], [email protected], [email protected] Keywords: lanthanum; cerium; magnesia crucible; inclusion; liquid steel Abstract. Two types of steels containing rare earths (RE) were smelted by the vacuum induction furnace with magnesia crucible, RE metals were added in liquid steel at the end of the smelting process, chemical compositions of the test steels were analyzed, and inclusions were observed by scanning electron microscope with energy dispersive spectrometer. The experimental results show that the yields of RE have no direct relationship with the oxygen and sulphur contents, but decrease with the increasing of RE addition amounts. The reaction between RE and MgO (the material of the crucible) is the major RE consumption mode, parts of the outer refractory are peeled off and become inclusions in the test steels. Because of the excessively active chemical properties, rare earths trend to react with refractory materials and metallurgical slag. Therefore, it is very difficult to utilize RE in the industrial production processes with con-casting, adding RE in the non-slag and non-refractory special processes may be feasible. Introduction Many beneficial functions of rare earths in ferrous materials were found, such as liquid steel deeply cleaning, inclusions modifying, solidification structure improving, and micro-alloying [1-3]. -
Thermodynamic and Kinetic Simulation of Y2o3 and Y2s3 Nonmetallic Phase Formation in Liquid Steel
J. Min. Metall. Sect. B-Metall., 56 (1) (2020) 11-25 Journal of Mining and Metallurgy, Section B: Metallurgy TherModynaMIc and kIneTIc SIMulaTIon of y2o3 and y2S3 nonMeTallIc phaSe forMaTIon In lIquId STeel S. Gerasin, d. kalisz *, J. Iwanciw * AGH University of Science and Technology, Faculty of Foundry Engineering, Kraków, Poland (Received 26 March 2019; accepted 30 August 2019) Abstract The current work deals with the phenomenon of non-metallic inclusions as a result of the addition of yttrium to the liquid steel as an alloying component. The order of introducing individual components determines their final content in steel, and this problem was analyzed using the WYK_Stal program developed at AGH. The study of Y2O3 and Y2S3 phase precipitation and the relationship between the addition of Y, Al, Ca, O, and S in molten steel was studied using the thermodynamic models based on Wagner’s formalism. The introductions of yttrium prior to aluminum brought about huge losses, and it mainly occurred due to the formation of oxides. The low oxygen content in the metal bath promotes the formation of yttrium sulphide. When yttrium is introduced after aluminum and calcium, yttrium is used for the precipitation of its sulfide, and in this way the manganese sulfide formation is reduced. Keywords: Yttrium; Non-metallic precipitate; Steel; Computer simulation 1. Introduction A much more advanced solution is represented by the quasichemical model. The following example shows The non-metallic phase being formed in liquid steel a model for a three-component system, e.g. AOx-BOy- during its deoxidization mainly consists of iron oxides, CO2, where it analyzes formation of pairs of atoms, i.e. -
Reaction Mechanism and Process Control of Hydrogen Reduction of Ammonium Perrhenate
metals Article Reaction Mechanism and Process Control of Hydrogen Reduction of Ammonium Perrhenate Junjie Tang 1,2, Yuan Sun 2,*, Chunwei Zhang 2,3, Long Wang 2, Yizhou Zhou 2,*, Dawei Fang 3 and Yan Liu 4 1 School of Biomedical & Chemical Engineering, Liaoning Institute of Science and Technology, Benxi 117004, China; [email protected] 2 Superalloys research department, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China; [email protected] (C.Z.); [email protected] (L.W.) 3 College of chemistry, Liaoning University, Shenyang 110036, China; davidfi[email protected] 4 Key Laboratory for Ecological Utilization of Multimetallic Mineral, Ministry of Education, Northeastern University, Shenyang 110819, China; [email protected] * Correspondence: [email protected] (Y.S.); [email protected] (Y.Z.); Tel.: +86-024-23971767 (Y.S.); +86-024-83978068 (Y.Z.) Received: 17 April 2020; Accepted: 13 May 2020; Published: 15 May 2020 Abstract: The preparation of rhenium powder by a hydrogen reduction of ammonium perrhenate is the only industrial production method. However, due to the uneven particle size distribution and large particle size of rhenium powder, it is difficult to prepare high-density rhenium ingot. Moreover, the existing process requires a secondary high-temperature reduction and the deoxidization process is complex and requires a high-temperature resistance of the equipment. Attempting to tackle the difficulties, this paper described a novel process to improve the particle size distribution uniformity and reduce the particle size of rhenium powder, aiming to produce a high-density rhenium ingot, and ammonium perrhenate is completely reduced by hydrogen at a low temperature. -
The Effect of Different Non-Metallic Inclusions on the Machinability of Steels
Materials 2015, 8, 751-783; doi:10.3390/ma8020751 OPEN ACCESS materials ISSN 1996-1944 www.mdpi.com/journal/materials Review The Effect of Different Non-Metallic Inclusions on the Machinability of Steels Niclas Ånmark 1,2,*, Andrey Karasev 1 and Pär Göran Jönsson 1 1 Department of Materials Science and Engineering, KTH Royal Institute of Technology, Stockholm SE-100-44, Sweden; E-Mails: [email protected] (A.K.); [email protected] (P.G.J.) 2 Department of Materials and Manufacturing, Swerea KIMAB, Kista SE-164-40, Sweden * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +46-0-72-508-43-42. Academic Editor: Richard Thackray Received: 19 December 2014 / Accepted: 11 February 2015 / Published: 16 February 2015 Abstract: Considerable research has been conducted over recent decades on the role of non-metallic inclusions and their link to the machinability of different steels. The present work reviews the mechanisms of steel fractures during different mechanical machining operations and the behavior of various non-metallic inclusions in a cutting zone. More specifically, the effects of composition, size, number and morphology of inclusions on machinability factors (such as cutting tool wear, power consumption, etc.) are discussed and summarized. Finally, some methods for modification of non-metallic inclusions in the liquid steel are considered to obtain a desired balance between mechanical properties and machinability of various steel grades. Keywords: inclusions; machinability; steel 1. Introduction Advances in steelmaking during the last six decades have resulted in steel grades with very low level of impurities. In recent years, new “clean and ultra-clean” steels have been developed and commercialized by steel producers around the world, thereby responding to the current and future market demands of steel having significantly improved mechanical properties (e.g., fatigue strength and impact toughness) and an improved corrosion resistance.