Lecture

Phase Transformations in Fe-C Alloys

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In course

MSE-234: Mechanical behaviour of materials

Ce cours est une introduction au comportement mécanique, à l'élaboration, à la structure et au cycle de vie des grandes classes de matériaux de structure (métaux, polymères, céramiques et composites) ...

Description

This lecture covers the phase transformations in Fe-C alloys, focusing on the formation of perlite and martensite. It explains the differences between hypoeutectoid and hypereutectoid steels, emphasizing the role of carbon content in the transformation process. The instructor discusses the significance of the Fe-C phase diagram, highlighting the critical temperatures for austenitization and the formation of different microstructures. Additionally, the lecture explores the concept of bainite formation as an alternative to martensite in the Fe-C system.

Instructors (3)

Julie Nathalie S Gheysen

Professionals experiences PhD student 2018–2022 Université Catholique de Louvain Teaching & PhD Courses Materials MSE-171 Introduction course of material science applied to usual building materials, especially concrete and metals. Description of their fabrication, mechanical and thermal properties and use in construction. Mechanical behaviour of materials MSE-234 This course provides an introduction to the mechanical behaviour, the processing, the structure and life-cycle o

Andreas Mortensen

Andreas Mortensen is currently Professor and Director of the Institute of Materials at the Swiss Federal Institute of Technology in Lausanne (EPFL), where he heads the Laboratory for Mechanical Metallurgy. He joined the faculty of EPFL 1997 after ten years, from 1986 to 1996, as a member of the faculty of the Department of Materials Science and Engineering at the Massachusetts Institute of Technology, where he held the successive titles of ALCOA Assistant Professor, Associate Professor, and Professor. His research is focussed on the processing, microstructural development and mechanical behavior of advanced metallic materials with particular focus on metal matrix composites and metal foams, on infiltration processing and capillarity, and on damage and fracture in metallic materials. He is author or co-author of two monographs, around one hundred and eighty scientific or technical publications and twelve patents. Born in San Francisco in 1957, of dual (Danish and US) nationality, Andreas Mortensen graduated in 1980 from the Ecole Nationale Supérieure des Mines de Paris with a Diplôme dIngénieur Civil, and earned his Ph.D. in the Department of Materials Science and Engineering at MIT in 1986. Besides his academic employment, he was a postdoctoral researcher at Nippon Steel during part of 1986, and was invited professor at the Ecole des Mines in Paris during the academic year 1995 to 1996. He is a member of the editorial committee of International Materials Reviews and has co-edited four books. He is a Fellow of ASM, a recipient of the Howe Medal and the Grossman Award of the American Society of Metals, was awarded the Péchiney Prize by the French Academy of Sciences and the Res Metallica Chair from the Katholieke Universiteit Leuven, received three EPFL teaching awards, is one of ISIs Highly Cited authors for Materials Science since 2002 and was awarded an ERC advanced grant in 2012.

David Hernandez Escobar

Official source

Ontological neighbourhood

Chemical engineering

Materials science: Alloys

Related concepts (28)

Heat treating

Heat treating (or heat treatment) is a group of industrial, thermal and metalworking processes used to alter the physical, and sometimes chemical, properties of a material. The most common application is metallurgical. Heat treatments are also used in the manufacture of many other materials, such as glass. Heat treatment involves the use of heating or chilling, normally to extreme temperatures, to achieve the desired result such as hardening or softening of a material.

Martempering

Martempering is also known as stepped quenching or interrupted quenching. In this process, steel is heated above the upper critical point (above the transformation range) and then quenched in a hot-oil, molten-salt, or molten-lead bath kept at a temperature of 150-300 °C. The workpiece is held at this temperature above martensite start (Ms) point until the temperature becomes uniform throughout the cross-section of the workpiece. After that, it is cooled in air or oil to room temperature. The steel is then tempered.

Austenite

Austenite, also known as gamma-phase iron (γ-Fe), is a metallic, non-magnetic allotrope of iron or a solid solution of iron with an alloying element. In plain-carbon steel, austenite exists above the critical eutectoid temperature of 1000 K (727 °C); other alloys of steel have different eutectoid temperatures. The austenite allotrope is named after Sir William Chandler Roberts-Austen (1843–1902); it exists at room temperature in some stainless steels due to the presence of nickel stabilizing the austenite at lower temperatures.

Carbon steel

Carbon steel is a steel with carbon content from about 0.05 up to 2.1 percent by weight. The definition of carbon steel from the American Iron and Steel Institute (AISI) states: no minimum content is specified or required for chromium, cobalt, molybdenum, nickel, niobium, titanium, tungsten, vanadium, zirconium, or any other element to be added to obtain a desired alloying effect; the specified minimum for copper does not exceed 0.40%; or the specified maximum for any of the following elements does not exceed the percentages noted: manganese 1.

Bainite

Bainite is a plate-like microstructure that forms in steels at temperatures of 125–550 °C (depending on alloy content). First described by E. S. Davenport and Edgar Bain, it is one of the products that may form when austenite (the face-centered cubic crystal structure of iron) is cooled past a temperature where it is no longer thermodynamically stable with respect to ferrite, cementite, or ferrite and cementite. Davenport and Bain originally described the microstructure as being similar in appearance to tempered martensite.

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