Kinetics of bainite transformation in steels

• The main kinetic features of the formation of bainite are discussed, firstly in relation to two incompatible hypotheses for the growth mechanism of bainitic ferrite. One is based on diffusionless growth of bainitic ferrite but diffusional growth of Widmanstätten ferrite. The other is based on the assumption that there is only one kind of acicular ferrite and it grows under simultaneous diffusion of carbon into the interior of the parent austenite. The kinetics of the first stage of bainite formation, the growth of acicular ferrite, is treated in detail because it has been subject to the more intensive research. The kinetics of the reactions by which cementite forms and the subsequent reactions, by which the transformation to bainite is completed, have been subject to less research.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Materialteknik -- Metallurgi och metalliska material (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering -- Metallurgy and Metallic Materials (hsv//eng)

Keyword

BS lengthwise growth

Bainite

Diffusion controlled

Diffusionless

Kinetics

Nucleation

TTT diagrams

Publication and Content Type

ref (subject category)

kap (subject category)