Mechanism and kinetics of the transformation of austenite to divorced pearlite

Uzlov, I. G.; Parusov, V. V.; Dolzhenkov, I. I.

doi:10.1007/bf00693266

Cited by 5 publications

(2 citation statements)

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“…On cooling through the eutectoid temperature, these cementite particles grow to absorb the excess carbon that is partitioned into the austenite as ferrite grows, thereby leading to a final structure of coarse cementite particles dispersed in a matrix of ferrite. This transformation is known as divorced pearlite since the product phases no longer grow cooperatively (Honda & Saito 1920;Whitley 1922;Gertsman 1966;Lur'e & Shteinberg 1969;Oyama et al 1984), and it leads directly to a spheroidized state during continuous cooling (Dolzhenkov & Lotsmanova 1974;Lyashenko et al 1986) or through specific heat treatments (Uzlov et al 1980), rather than to one which is a lamellar pearlite. The two kinds of transformations are illustrated schematically in figure 1.…”

Section: Introductionmentioning

confidence: 99%

Divorced pearlite in steels

Pandit

Bhadeshia

2012

Proc. R. Soc. A.

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Steels containing large carbon concentrations are used particularly when a high hardness is required, for example, in the manufacture of components such as bearings. This, however, makes it difficult to shape or machine the alloys during the process of component manufacture unless they are first heat-treated into a softened condition. One method of achieving this economically is to generate a microstructure known as divorced pearlite, in which ferrite and cementite grow from the austenite in a non-cooperative manner, leading to a final microstructure that consists of coarse, spherical particles of cementite dispersed in a matrix of ferrite. This is in contrast to the harder lamellar pearlite which normally develops when high-carbon steels are cooled. The theoretical framework governing the transition from the divorced to the lamellar form is developed and validated experimentally.

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Section: Introductionmentioning

confidence: 99%

Divorced pearlite in steels

Pandit

Bhadeshia

2012

Proc. R. Soc. A.

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“…Conventional bearing steels rely on the presence of proeutectoid cementite to stimulate the formation of divorced rather than lamellar pearlite when the austenite (c) is cooled. In the divorced eutectoid, [18][19][20][21][22][23][24][25][26] the ferrite (a) and cementite (h) transformations are no longer directly coupled at the transformation front with austenite, but as the a/c interface advances during cooling, the proeutectoid cementite particles that already exist, simply absorb the excess carbon and grow bigger, leading to a final, soft microstructure consisting of spheroidal cementite particles in a matrix of ferrite. The continuous cooling process associated with the divorced eutectoid reaction is relatively rapid and the resulting structure usually has about half the hardness of lamellar pearlite.…”

Section: Introductionmentioning

confidence: 99%

Spheroidisation of hypereutectoid state of nanostructured bainitic steel

Luo

Peet

Ooi

et al. 2014

Materials Science and Technology

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Nanostructured bainite is extremely resistant to severe tempering making it difficult to reduce its hardness sufficiently to allow certain processing before heat treatment into its final state. An attempt is therefore made to introduce the divorced pearlite reaction that relies on the presence of pro-eutectoid cementite in the austenite in order to produce a microstructure containing spheroidal cementite particles simply by continuous cooling from the two phase austenite and cementite field. It is demonstrated that dramatically reduced hardness values can be achieved using this method.

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