Quantification of the Microstructures of Hypoeutectic White Cast Iron Using
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High-Carbon Steels: Fully Pearlitic Microstructures and Applications
© 2005 ASM International. All Rights Reserved. www.asminternational.org Steels: Processing, Structure, and Performance (#05140G) CHAPTER 15 High-Carbon Steels: Fully Pearlitic Microstructures and Applications Introduction THE TRANSFORMATION OF AUSTENITE to pearlite has been de- scribed in Chapter 4, “Pearlite, Ferrite, and Cementite,” and Chapter 13, “Normalizing, Annealing, and Spheroidizing Treatments; Ferrite/Pearlite Microstructures in Medium-Carbon Steels,” which have shown that as microstructure becomes fully pearlitic as steel carbon content approaches the eutectiod composition, around 0.80% carbon, strength increases, but resistance to cleavage fracture decreases. This chapter describes the me- chanical properties and demanding applications for which steels with fully pearlitic microstructures are well suited. With increasing cooling rates in the pearlite continuous cooling trans- formation range, or with isothermal transformation temperatures ap- proaching the pearlite nose of isothermal transformation diagrams, Fig. 4.3 in Chapter 4, the interlamellar spacing of pearlitic ferrite and cementite becomes very fine. As a result, for most ferrite/pearlite microstructures, the interlamellar spacing is too fine to be resolved in the light microscope, and the pearlite appears uniformly dark. Therefore, to resolve the inter- lamellar spacing of pearlite, scanning electron microscopy, and for the finest spacings, transmission electron microscopy (TEM), are necessary to resolve the two-phase structure of pearlite. Figure 15.1 is a TEM mi- crograph showing very fine interlamellar structure in a colony of pearlite from a high-carbon steel rail. This remarkable composite structure of duc- © 2005 ASM International. All Rights Reserved. www.asminternational.org Steels: Processing, Structure, and Performance (#05140G) 282 / Steels: Processing, Structure, and Performance tile ferrite and high-strength cementite is the base microstructure for rail and the starting microstructure for high-strength wire applications. -
Carbon Steel
EN380 12-wk Exam Solution Fall 2019 Carbon Steel. 1. [19 pts] Three compositions of plain carbon steel are cooled very slowly in a turned-off furnace from ≈ 830◦C (see phase diagram below). For each composition, the FCC grains of γ−austenite (prior to transformation) are shown in an optical micrograph of the material surface. Sketch and label the phases making up the microstructures present in the right hand micrograph just after the austenite has completed transformation (note: the gray outlines of the prior γ grains may prove helpful). (a) [4 pts] C0 = 0:42% C (by wt). 830◦C 726◦C EN380 12-wk Exam Solution Page 1 Fall 2019 EN380 12-wk Exam Solution Fall 2019 (b) [4 pts] C0 = 0:80% C (by wt). 830◦C 726◦C (c) [4 pts] C0 = 1:05% C (by wt). 830◦C 726◦C (d) [7 pts] For the composition of part (c), C0 = 1:05% C (by wt), calculate the fraction of the solid that is pearlite at 726◦C. CF e3C − C0 6:67% − 1:05% Wpearlite = Wγ at 728◦C = = = 95:74% Pearlite CF e3C − Cγ 6:67% − 0:8% EN380 12-wk Exam Solution Page 2 Fall 2019 EN380 12-wk Exam Solution Fall 2019 2. [11 pts] Write in the correct term for each of the following related to carbon steels[1 pt each] (terms will be used exactly once): This material features carbon content in excess of Cast Iron 2:0% and is known for its excellent hardness, wear resistance, machinability and castability. -
Structure/Property Relationships in Irons and Steels Bruce L
Copyright © 1998 ASM International® Metals Handbook Desk Edition, Second Edition All rights reserved. J.R. Davis, Editor, p 153-173 www.asminternational.org Structure/Property Relationships in Irons and Steels Bruce L. Bramfitt, Homer Research Laboratories, Bethlehem Steel Corporation Basis of Material Selection ............................................... 153 Role of Microstructure .................................................. 155 Ferrite ............................................................. 156 Pearlite ............................................................ 158 Ferrite-Pearl ite ....................................................... 160 Bainite ............................................................ 162 Martensite .................................... ...................... 164 Austenite ........................................................... 169 Ferrite-Cementite ..................................................... 170 Ferrite-Martensite .................................................... 171 Ferrite-Austenite ..................................................... 171 Graphite ........................................................... 172 Cementite .......................................................... 172 This Section was adapted from Materials 5election and Design, Volume 20, ASM Handbook, 1997, pages 357-382. Additional information can also be found in the Sections on cast irons and steels which immediately follow in this Handbook and by consulting the index. THE PROPERTIES of irons and steels -
Chapter 12: Phase Transformations
Chapter 12: Phase Transformations ISSUES TO ADDRESS... • Transforming one phase into another takes time. Fe Fe C Eutectoid 3 γ transformation (cementite) (Austenite) + α C FCC (ferrite) (BCC) • How does the rate of transformation depend on time and temperature ? • Is it possible to slow down transformations so that non-equilibrium structures are formed? • Are the mechanical properties of non-equilibrium structures more desirable than equilibrium ones? AMSE 205 Spring ‘2016 Chapter 12 - 1 Phase Transformations Nucleation – nuclei (seeds) act as templates on which crystals grow – for nucleus to form rate of addition of atoms to nucleus must be faster than rate of loss – once nucleated, growth proceeds until equilibrium is attained Driving force to nucleate increases as we increase ΔT – supercooling (eutectic, eutectoid) – superheating (peritectic) Small supercooling slow nucleation rate - few nuclei - large crystals Large supercooling rapid nucleation rate - many nuclei - small crystals AMSE 205 Spring ‘2016 Chapter 12 - 2 Solidification: Nucleation Types • Homogeneous nucleation – nuclei form in the bulk of liquid metal – requires considerable supercooling (typically 80-300 °C) • Heterogeneous nucleation – much easier since stable “nucleating surface” is already present — e.g., mold wall, impurities in liquid phase – only very slight supercooling (0.1-10 °C) AMSE 205 Spring ‘2016 Chapter 12 - 3 Homogeneous Nucleation & Energy Effects Surface Free Energy- destabilizes the nuclei (it takes energy to make an interface) γ = surface tension ΔGT = Total Free Energy = ΔGS + ΔGV Volume (Bulk) Free Energy – stabilizes the nuclei (releases energy) r* = critical nucleus: for r < r* nuclei shrink; for r > r* nuclei grow (to reduce energy) Adapted from Fig.12.2(b), Callister & Rethwisch 9e. -
New Extremely Low Carbon Bainitic High-Strength Steel Bar Having Excellent Machinability and Toughness Produced by TPCP Technology*
KAWASAKI STEEL TECHNICAL REPORT No. 47 December 2002 New Extremely Low Carbon Bainitic High-Strength Steel Bar Having Excellent Machinability and Toughness Produced by TPCP Technology* Synopsis: A non heat-treated high strength steel bar for machine structural use through a thermo-mechanical precipita- tion control process (hereafter, referred to as TPCP) has been developed. The newly developed TPCP is a tech- nique for controlling the strength of the steel by precipi- tation hardening effected with the benefit of an extremely low carbon bainitic microstructure. The carbon content Kazukuni Hase Toshiyuki Hoshino Keniti Amano of the steel is decreased to below 0.02 mass% for realiz- Senior Researcher, Dr. Eng., Senior Dr. Eng., General Plate, Shape & Joining Researcher, Plate, Manager, Plate, Shape ing the proper microstructure, which improves both the Lab., Shape & Joining Lab., & Joining Lab., notch toughness and machinability. In order to make the Technical Res. Labs. Technical Res. Labs. Technical Res. Labs. microstructure bainitic and to obtain effective precipita- tion hardening, some micro-alloying elements are added. The developed steel manufactured with these advanced techniques showed a higher impact value, higher yield strength and better machinability than those 1 Introdution of the quenched and tempered AISI 4137 steel. The impact value of the steel is 250 J/cm2 or more at room In the fields of automobiles and industrial machines temperature. The problem of the reduction in yield ratio, where carbon steels and low alloy steels -
Materials Technology – Placement
MATERIAL TECHNOLOGY 01. An eutectoid steel consists of A. Wholly pearlite B. Pearlite and ferrite C. Wholly austenite D. Pearlite and cementite ANSWER: A 02. Iron-carbon alloys containing 1.7 to 4.3% carbon are known as A. Eutectic cast irons B. Hypo-eutectic cast irons C. Hyper-eutectic cast irons D. Eutectoid cast irons ANSWER: B 03. The hardness of steel increases if it contains A. Pearlite B. Ferrite C. Cementite D. Martensite ANSWER: C 04. Pearlite is a combination of A. Ferrite and cementite B. Ferrite and austenite C. Ferrite and iron graphite D. Pearlite and ferrite ANSWER: A 05. Austenite is a combination of A. Ferrite and cementite B. Cementite and gamma iron C. Ferrite and austenite D. Pearlite and ferrite ANSWER: B 06. Maximum percentage of carbon in ferrite is A. 0.025% B. 0.06% C. 0.1% D. 0.25% ANSWER: A 07. Maximum percentage of carbon in austenite is A. 0.025% B. 0.8% 1 C. 1.25% D. 1.7% ANSWER: D 08. Pure iron is the structure of A. Ferrite B. Pearlite C. Austenite D. Ferrite and pearlite ANSWER: A 09. Austenite phase in Iron-Carbon equilibrium diagram _______ A. Is face centered cubic structure B. Has magnetic phase C. Exists below 727o C D. Has body centered cubic structure ANSWER: A 10. What is the crystal structure of Alpha-ferrite? A. Body centered cubic structure B. Face centered cubic structure C. Orthorhombic crystal structure D. Tetragonal crystal structure ANSWER: A 11. In Iron-Carbon equilibrium diagram, at which temperature cementite changes fromferromagnetic to paramagnetic character? A. -
Cast Irons$ KB Rundman, Michigan Technological University, Houghton, MI, USA F Iacoviello, Università Di Cassino E Del Lazio Meridionale, DICEM, Cassino (FR), Italy
Cast Irons$ KB Rundman, Michigan Technological University, Houghton, MI, USA F Iacoviello, Università di Cassino e del Lazio Meridionale, DICEM, Cassino (FR), Italy r 2016 Elsevier Inc. All rights reserved. 1 Metallurgy of Cast Iron 1 2 Solidification of a Hypoeutectic Gray Iron Alloy With CE¼4.0 3 3 Matrix Microstructures in Graphitic Cast Irons – Cooling Below the Eutectic 3 4 Microstructure and Mechanical Properties of Gray Cast Iron 4 5 Effect of Carbon Equivalent 5 6 Effect of Matrix Microstructure 5 7 Effect of Alloying Elements 5 8 Classes of Gray Cast Irons and Brinell Hardness 5 9 Ductile Cast Iron 5 10 Production of Ductile Iron 6 11 Solidification and Microstructures of Hypereutectic Ductile Cast Irons 6 12 Mechanical Properties of Ductile Cast Iron 7 13 As-cast and Quenched and Tempered Grades of Ductile Iron 8 14 Malleable Cast Iron, Processing, Microstructure, and Mechanical Properties 8 15 Compacted Graphite Iron 9 16 Austempered Ductile Cast Iron 9 17 The Metastable Phase Diagram and Stabilized Austenite 9 18 Control of Mechanical Properties of ADI 10 19 Conclusion 10 References 11 Further Reading 11 Cast irons have played an important role in the development of the human species. They have been produced in various compositions for thousands of years. Most often they have been used in the as-cast form to satisfy structural and shape requirements. The mechanical and physical properties of cast irons have been enhanced through understanding of the funda- mental relationships between microstructure (phases, microconstituents, and the distribution of those constituents) and the process variables of iron composition, heat treatment, and the introduction of significant additives in molten metal processing. -
Heat Treatment
Heat Treatment R. Manna Assistant Professor Centre of Advanced Study Department of Metallurgical Engineering Institute of Technology Banaras Hindu University Varanasi-221 005, India [email protected] Tata Steel-TRAERF Faculty Fellowship Visiting Scholar Department of Materials Science and Metallurgy University of Cambridge Pembroke Street, Cambridge, CB2 3QZ [email protected] HEAT TREATMENT Fundamentals Fe-C equilibrium diagram. Isothermal and continuous cooling transformation diagrams for plain carbon and alloy steels. Microstructure and mechanical properties of pearlite, bainite and martensite. Austenitic grain size. Hardenability, its measurement and control. Processes Annealing, normalising and hardening of steels, quenching media, tempering. Homogenisation. Dimensional and compositional changes during heat treatment. Residual stresses and decarburisation. 2 Surface Hardening Case carburising, nitriding, carbonitriding, induction and flame hardening processes. Special Grade Steels Stainless steels, high speed tool steels, maraging steels, high strength low alloy steels. Cast irons White, gray and spheroidal graphitic cast irons Nonferrous Metals Annealing of cold worked metals. Recovery, recrystallisation and grain growth. Heat treatment of aluminum, copper, magnesium, titanium and nickel alloys. Temper designations for aluminum and magnesium alloys. Controlled Atmospheres Oxidizing, reducing and neutral atmospheres. 3 Suggested Reading R. E. Reed-Hill and R. Abbaschian: Physical Metallurgy Principles, PWS , Publishing Company, Boston, Third Edition. Vijendra Singh: Heat treatment of Metals, Standard Publishers Distributors, Delhi. Anil Kumar Sinha: Physical Metallurgy Handbook, McGraw- Hill Publication. H. K. D. H. Bhadeshia and R. W. K. Honeycombe: Steels- Microstructure and Properties, Butterworth-Heinemann, Third Edition, 2006 R. C. Sharma: Principles of Heat Treatment of Steels, New Age International (P) Ltd. Publisher. Charlie R. Brooks: Heat Treatment: Structure and Properties of Nonferrous Alloys, A. -
Enghandbook.Pdf
785.392.3017 FAX 785.392.2845 Box 232, Exit 49 G.L. Huyett Expy Minneapolis, KS 67467 ENGINEERING HANDBOOK TECHNICAL INFORMATION STEELMAKING Basic descriptions of making carbon, alloy, stainless, and tool steel p. 4. METALS & ALLOYS Carbon grades, types, and numbering systems; glossary p. 13. Identification factors and composition standards p. 27. CHEMICAL CONTENT This document and the information contained herein is not Quenching, hardening, and other thermal modifications p. 30. HEAT TREATMENT a design standard, design guide or otherwise, but is here TESTING THE HARDNESS OF METALS Types and comparisons; glossary p. 34. solely for the convenience of our customers. For more Comparisons of ductility, stresses; glossary p.41. design assistance MECHANICAL PROPERTIES OF METAL contact our plant or consult the Machinery G.L. Huyett’s distinct capabilities; glossary p. 53. Handbook, published MANUFACTURING PROCESSES by Industrial Press Inc., New York. COATING, PLATING & THE COLORING OF METALS Finishes p. 81. CONVERSION CHARTS Imperial and metric p. 84. 1 TABLE OF CONTENTS Introduction 3 Steelmaking 4 Metals and Alloys 13 Designations for Chemical Content 27 Designations for Heat Treatment 30 Testing the Hardness of Metals 34 Mechanical Properties of Metal 41 Manufacturing Processes 53 Manufacturing Glossary 57 Conversion Coating, Plating, and the Coloring of Metals 81 Conversion Charts 84 Links and Related Sites 89 Index 90 Box 232 • Exit 49 G.L. Huyett Expressway • Minneapolis, Kansas 67467 785-392-3017 • Fax 785-392-2845 • [email protected] • www.huyett.com INTRODUCTION & ACKNOWLEDGMENTS This document was created based on research and experience of Huyett staff. Invaluable technical information, including statistical data contained in the tables, is from the 26th Edition Machinery Handbook, copyrighted and published in 2000 by Industrial Press, Inc. -
EN380 Homework #7 Solution
EN380 Homework #7 Solution 1. What are the criteria for two metals to form a perfect substitutional alloy (that is, these two will form the same crystal phase at all potential concentrations of each species)? • Atomic radii must not differ by more than 15%. • Crystalline Structure must be the same (BCC and BCC, FCC and FCC, etc.). • No appreciable difference in electronegativity. • Elements should have the same valence state. 2. Sketch a qualitative plot of σY vs % elongation for the following steel microstructures: (a) Ferrite (α) (b) Bainite (c) Martinsite (d) Coarse Pearlite (e) Fine Pearlite 1 3. The phase diagram for iron-iron carbide (F e - F e3C) is shown below. For a 0:95% C steel (i.e. 1095 series) at a temperature just below the eutectoid temperature (727◦C) determine: (a)% C present in the ferrite (α).0 :02% (b)% C present in the cementite (F e3C).6 :67% orange CF e3C −C0 6:67%−0:95% (c) total % of the steel that is ferrite (α). Wα = = = = 86:02% purple+orange CF e3C −Cα 6:67%−0:02% (d) total % of the steel that is cementite (F e3C). purple C0−Cα 0:95%−0:02% WF e3C = = = 13:98% purple+orange CF e3C −Cα 6:67%−0:02% 2 (e) % of steel that is pearlite. This is the same as finding how much austenite, γ, was present just above the eutectoid temper- ature. Draw the tie line just above 727◦C. Cα = 0:02% Cγ = 0:8% green CF e3C − C0 6:67% − 0:95% Wγ = = = = 97:44% red + green CF e3C − Cγ 6:67% − 0:8% (f) % of steel that is proeutectoid ferrite. -
Formation of Faceted Excess Carbides in Damascus Steels Ledeburite Class
Journal of Materials Science and Engineering B 8 (1-2) (2018) 36-44 doi: 10.17265/2161-6221/2018.1-2.006 D DAVID PUBLISHING Formation of Faceted Excess Carbides in Damascus Steels Ledeburite Class Dmitry Sukhanov1 and Natalia Plotnikova2 1. ASK-MSC Company (Metallurgy), Moscow 117246, Russia 2. Novosibirsk State Technical University, Novosibirsk 630073, Russia Abstract: In this research was developed stages of formation troostite-carbide structure into pure Damascus steel ledeburite class type BU22А obtained by vacuum melting. In the first stage of the technological process, continuous carbides sheath was formed along the boundaries of austenitic grains, which morphologically resembles the inclusion of ledeburite. In the second stage of the process, there is a seal and faceted large carbide formations of eutectic type. In the third stage of the technological process, troostite matrix is formed with a faceted eutectic carbide non-uniformly distributed in the direction of the deformation with size from 5.0 μm to 20 μm. It found that the stoichiometric composition of faceted eutectic carbides is in the range of 34 < C < 36 (atom %), which corresponds to -carbide type Fe2C with hexagonal close-packed lattice. Considering stages of transformation of metastable ledeburite in the faceted eutectic -carbides type Fe2C, it revealed that the duration of isothermal exposure during heating to the eutectic temperature, is an integral part of the process of formation of new excess carbides type Fe2C with a hexagonal close-packed lattice. It is shown that troostite-carbide structure Damascus steel ledeburite class (BU22А), with volume fraction of excess -carbide more than 20%, is fully consistent with the highest grades of Indian steels type Wootz. -
Influence of Microstructure on the Corrosion of Archaeological Iron Observed Using 3D Synchrotron Micro-Tomography
Accepted Manuscript Title: Influence of microstructure on the corrosion of archaeological iron observed using 3D synchrotron micro-tomography Authors: H.J. Simon, G. Cibin, C. Reinhard, Y. Liu, E. Schofield, I.C. Freestone PII: S0010-938X(19)30244-6 DOI: https://doi.org/10.1016/j.corsci.2019.108132 Article Number: 108132 Reference: CS 108132 To appear in: Received date: 1 February 2019 Revised date: 13 July 2019 Accepted date: 30 July 2019 Please cite this article as: Simon HJ, Cibin G, Reinhard C, Liu Y, Schofield E, Freestone IC, Influence of microstructure on the corrosion of archaeological iron observed using 3D synchrotron micro-tomography, Corrosion Science (2019), https://doi.org/10.1016/j.corsci.2019.108132 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Influence of microstructure on the corrosion of archaeological iron observed using 3D synchrotron micro-tomography H. J. Simon,1,2* G. Cibin,2 C. Reinhard,2 Y. Liu,1 E. Schofield,3 I. C. Freestone1 1 UCL Institute of Archaeology, 31-34 Gordon Square, London, WC1H 0PY, UK 2 Diamond Light Source, Harwell Campus, Didcot, Oxfordshire, OX11 0DE, UK 3 The Mary Rose Trust, College