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Steel Transformation


  • 46:19 TRIP-assisted steels: role of retained austenite

    TRIP-assisted steels: role of retained austenite

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    TRIP stands for transformation-induced plasticity. TRIP-assisted steels have a microstructure which is predominantly allotriomorphic ferrite, with a small fraction of bainitic ferrite and carbon-enriched retained austenite. It is the latter which undergoe

  • 45:50 Characteristics of Martensite in Steels

    Characteristics of Martensite in Steels

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    Red hot steel is austenitic. If cooled sufficiently rapidly, it transforms without diffusion into martensite. The characteristics of martensite are explained in this lecture which should be useful to anyone interested in physical metallurgy and steels.The

  • 42:04 Phenomenological Theory of Martensite in Steels

    Phenomenological Theory of Martensite in Steels

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    This elegant crystallographic theory is able to explain all of the puzzling features of martensite - why it grows on strange habit planes, why the orientation relationship is irrational, the nature of the deformation accompanying the transformation and mu

  • 43:38 Martensitic Transformations, Part I

    Martensitic Transformations, Part I

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    Lecture on the nature of martensitic transformations in steels and other materials. In this part I we examine the characteristics of martensite. In part II we explain these in terms of the crystallographic theory of martensite.The video is particularly re

  • 28:39 Martensitic Transformations, Part II

    Martensitic Transformations, Part II

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    The crystallographic theory of martensite is explained in this lecture. Martensite is a phase resulting from the diffusionless transformation of austenite. Although martensite occurs in many materials, it is of the greatest significance in steels.This lec

  • 48:30 Phase transformations in steels 23

    Phase transformations in steels 23

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    Lecture on martensite by Professor Dong Woo Suh of the Graduate Institute of Ferrous Technology, POSTECH, Republic of Koreahttp://cml.postech.ac.kr

  • 03:23 Equilibrium between tetragonal ferrite and austenite

    Equilibrium between tetragonal ferrite and austenite

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    There are precise observations which indicate the reluctance of excess carbon within bainite or martensite to partition into adjacent austenite in spite of prolonged heat treatment at temperatures where carbon is mobile. To explain this, we report the fir

  • 01:07 Jominy end quench hardenability test

    Jominy end quench hardenability test

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    A test designed to discover how much of the steel will transform into martensite on quenching into water from a hot state where the sample is fully austenitic. A steel with greater hardenability can be hardened to a greater depth.http://www.msm.cam.ac.uk/

  • 00:44 Nickel-titanium shape memory effect

    Nickel-titanium shape memory effect

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    Professor Koichi Tsuchiya of the Toyohashi University of Technology, Japan.Nickel-titanium shape memory metal is usually available in wire form, made by wire drawing. Because of the lack of ductility, it is much more difficult to fabricate the alloy in sh

  • 00:21 Magnetic shape memory martensite

    Magnetic shape memory martensite

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    The sample here is a Ni-24Mn-24Ga at. alloy. This is a shape memory alloy but in addition, the martensite if ferromagnetic. This means that the martensitic transformation can be induced by an applied magnetic field; alternatively, the twins in the martens

  • 00:06 Illustration of displacive phase transformation

    Illustration of displacive phase transformation

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    A displacive transformation occurs without diffusion, so bonds between neighbouring atoms are not broken. Nevertheless, the pattern in which the atoms are arranged changes, i.e., a change in crystal structure without diffusion. There is an atomic correspo

  • 02:00 Reconstructive and Displacive Transformations: Part VI

    Reconstructive and Displacive Transformations: Part VI

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    Part 6 in the story of displacive and reconstructive phase changes. The nature of nucleation is considered for the two mechanisms of transformation, one involving random fluctuations and the other a systematic set of displacements by the dissociation of d

  • 01:58 Reconstructive and Displacive Transformations: Part V

    Reconstructive and Displacive Transformations: Part V

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    Part 5 in the story of displacive and reconstructive phase changes. Here the twins describe a phase transformation in which substitutional lattice is deformed into the new structure, but interstitials diffuse without affecting the crystallography of the r

  • 01:40 Reconstructive and Displacive Transformations: Part IV

    Reconstructive and Displacive Transformations: Part IV

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    Part 4 in the story of displacive and reconstructive phase changes.Displacive transformations involve the coordinatedmovement of atoms. Such movements cannot besustained against strong defects such as grain boundaries. This is why martensite or bainite pl

  • 01:36 Reconstructive and Displacive Phase Transformations: Part III

    Reconstructive and Displacive Phase Transformations: Part III

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    Solid-state phase transformation mechanisms in pure iron. How does one distinguish between a diffusionless martensitic transformation and a diffusional transformation to ferrite when it occurs in a pure substance? There is no change in chemical compositio

  • 01:41 Reconstructive and Displacive Phase Transformations: Part II

    Reconstructive and Displacive Phase Transformations: Part II

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    Displacive transformations are those in which the change in crystal structure is achieved by a physical deformation. Reconstructive transformations occur by the long-range diffusion of atoms, with the migration happening in such a way that the strain ener

  • 00:57 Displacive and Reconstructive Phase Transformations: Part I

    Displacive and Reconstructive Phase Transformations: Part I

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    Displacive transformations are those in which the change in crystal structure is achieved by a physical deformation. Reconstructive transformations occur by the long-range diffusion of atoms, with the migration happening in such a way that the strain ener

  • 00:36 Martensitic transformation

    Martensitic transformation

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    A movie of martensitic transformation in Fe-0.18C-0.2Si-0.9Mn-2.9Ni-1.5Cr-0.4Mo wt steel, using confocal laser microscopy. The time and temperature are indicated on the left hand corner. The contrast arises from the displacements caused by the phase chang

  • 00:36 Hardening of steel axles using lasers

    Hardening of steel axles using lasers

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    Hardening of steel axles, using a 2.8 kW high-power diode laser. The surface hardening process relies upon a thermally induced phase change in iron alloys with significant carbon content. The appeal of transformation hardening by laser is the fact that on

  • 23:42 Calculation of Crystallographic Texture due to Displacive Transformations in Steels

    Calculation of Crystallographic Texture due to Displacive Transformations in Steels

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    An introduction to the mathematical estimation of the crystallographic texture and microstructure resulting from the displacive transformation of austenite in steels, under the influence of an externally applied system of stresses. It begins with an intro

  • 00:30 Martensite and Bainite: Bain Correspondence

    Martensite and Bainite: Bain Correspondence

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    This movie shows two adjacent Cubic-F unit cells of austenite, with a body-centred tetragonal (b.c.t.) unit cells of austenite highlighted by colouring some of the lattice points in red. Notice that the body-centred cell is simply another representation o

  • 00:14 Martensite and Bainite: Bain Correspondence

    Martensite and Bainite: Bain Correspondence

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    This movie shows two adjacent Cubic-F unit cells of austenite. It is possible to identify within this, a body-centred tetragonal (b.c.t.) unit cells of austenite. Notice that the body-centred cell is simply another representation of austenite. The relatio

  • 03:26 Thermoelastic martensite in Fe_3Pt

    Thermoelastic martensite in Fe_3Pt

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    Observation of thermoelastic martensitic transformation and reversal in an iron-platinum alloy. The movie is provided courtesy of Professor Druce Dunne who conducted this research at the University of Illinois in Urbana Champaign, and is now at the Univer

  • 54:13 Phase transformations in steels 3, 2014

    Phase transformations in steels 3, 2014

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    A series of lectures on solid-state phase transformations in steel, given at POSTECH, by Professor H. K. D. H. Bhadeshia. This one finishes off the thermodynamics of martensitic transformation and makes a start on the characteristics of the bainite transf

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