Effect of the Stability of Retained Austenite on Elongation in Hot-Rolled High Strength Steels

The effect of plastic stability of retained austenite on elongation was investigated using Fe-0.17%C-1.99%Si-1.77%Mn hot-rolled high strength steel sheets produced in the mill-scale test.The results obtained are as follows;(1) Total elongation, uniform elongation and local elongation have a tendency to be improved with the increase of the plastic stability of retained austenite when volume fraction of retained austenite is nearly equal.(2) The plastic stability of retained austenite has a tendency to be improved with the increase of carbon contents in retained austenite.(3) The volume fraction of retained austenite at 15% tensile strain, kp and n-value over very small strain interval have strong relation to elongation. They are considered to be indexes for the effect of the plastic stability of retained austenite on elongation.