Dimensional changes and microstructural evolution in a B-bearing steel in the simulated forming and quenching process

Citation
Mc. Somani et al., Dimensional changes and microstructural evolution in a B-bearing steel in the simulated forming and quenching process, ISIJ INT, 41(4), 2001, pp. 361-367
Citations number
14
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Metallurgy
Journal title
ISIJ INTERNATIONAL
ISSN journal
0915-1559 → ACNP
Volume
41
Issue
4
Year of publication
2001
Pages
361 - 367
Database
ISI
SICI code
0915-1559(2001)41:4<361:DCAMEI>2.0.ZU;2-C
Abstract
To improve the modelling of the behaviour of steel profiles in the forming and quenching process, the influences of high-temperature plastic deformati on and applied stress on the martensitic transformation were investigated i n a B-bearing steel by dilatometric measurements and compression tests. The plastic deformation of austenite was found to enhance ferrite formation so significantly that the dilatation due to the low-temperature transformatio n decreases even at a cooling rate of 280 degreesC/s. The presence of ferri te in the microstructure results in markedly lower hardness and flow stress than the completely martensitic microstructure. Possibilities to avoid fer rite formation have been discussed. Stress applied during the martensitic t ransformation increases diametric dilatation by as much as 200 % under axia l compression, which seems to result from the preferred orientation of the martensite formed. However, subsequent to a high-temperature plastic deform ation, the influence of applied stress remains much smaller.