Diffusion in growth of bainite

Journal Article · Thu Sep 01 04:00:00 EDT 1994 · Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States)

DOI:https://doi.org/10.1007/BF02649044· OSTI ID:6989700

Hillert, M ^[1]

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1. Royal Inst. of Tech., Stockholm (Sweden). Div. of Physical Metallurgy

Edgewise growth rates for Widmanstaetten ferrite and bainite in low alloy steels can be represented with an empirical equation showing proportionality to the square of the supersaturation of the austenite. The proportionality constant has a value in reasonable agreement with the assumption of rate control by carbon diffusion. The growth rates are too low to give a noticeable supersaturation of carbon in the growing ferrite. The experimental B[sub s] for low alloy steels does not seem to be related to the T[sub 0] line, nor does B[sub s] evaluated from the incomplete transformation to bainite for an alloy steel. By assuming rate control by carbon diffusion, the empirical equation can be used to calculate the growth rate under paraequilibrium or no partition, local equilibrium (NPLE) conditions. Experimental growth rates for a similar steel falls in-between. The fact that paraequilibrium does not seem to apply is taken as an indication that the [alpha]/[gamma] interface for Widmanstaetten ferrite and bainite is not of a purely martensitic type.

• OSTI ID: 6989700
• Journal Information: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States), Journal Name: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States) Vol. 25:9; ISSN 0360-2133; ISSN MTTABN
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
ALLOYS
CRYSTAL-PHASE TRANSFORMATIONS
IRON ALLOYS
IRON BASE ALLOYS
LOW ALLOY STEELS
MICROSTRUCTURE
PHASE STUDIES
PHASE TRANSFORMATIONS
STEELS
TEMPERATURE DEPENDENCE
WIDMANSTAETTEN STRUCTURE