1995 Volume 81 Issue 6 Pages 649-654
Static recovery and recrystallization behavior of α grains of low carbon steels have been studied by means of hot working simulator. Static recovery rate increases as carbon content increases up to 0.02mass% and is nearly constant above 0.02mass%. The critical strain for recrystallization, εm, decreases with decreasing initial grain size and strain rate and with increasing deformation temperature. Recrystallized grains are developed within an interval of 50 ms after straining over εm. Recrystallized α grain sizes decrease with decreasing initial grain size and deformation temperature, and with increasing strain. Recrystallized fraction increases with decreasing initial grain size and with increasing strain and deformation temperature. 2-step hot working tests at various temperatures above and below Ae3 have been carried out to examine the strain induced transformation from hot worked austenite to ferrite.
On the basis of these results, a prediction model of α volume fraction and grain size is developed and its availability in the case of intercritical rolling was certified.