Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7971700 | Materials Science and Engineering: A | 2018 | 7 Pages |
Abstract
The effect of hot rolling temperature on microstructural evolution and mechanical properties of 0.05C-5Mn (wt%) steel was investigated. With the decrease of hot rolling temperature from 1150â¯Â°C to 900â¯Â°C, the average size of prior austenite grain was decreased from ~ 40â¯Âµm to ~20â¯Âµm, and average width of martensite lath was refined from ~ 400â¯nm to ~ 250â¯nm. The morphology of reversed austenite was changed from film-like shape to block-like shape, and the volume fraction of reversed austenite was increased from 14.75% to 16.28% because of the stimulated nucleation in refined prior austenite grains by rolling at lower temperature. The yield strength, tensile strength and the total elongation were simultaneously increased from 673â¯MPa, 805â¯MPa, and 27.5% to 704â¯MPa, 846â¯MPa, and 31%, respectively. The low temperature impact toughness was significantly enhanced from 133â¯J to 222â¯J at ââ¯40â¯Â°C. The significant improvement in mechanical properties by lower hot rolling temperature were attributed to both the refined tempered martensite lath with higher density of high misorientation grain boundaries and the active TRIP effect of reversed austenite with suitable mechanical stability.
Related Topics
Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
S. Yu, L.X. Du, J. Hu, R.D.K. Misra,