【摘要】 针对Q420钢特厚板的生产工艺特点,利用Gleeble-2000热模拟试验机研究了该钢变形和未变形条件下的连续冷却过程中相变行为及组织演变规律,绘制了该钢的连续冷却转变(CCT)曲线,分析了控轧控冷工艺对其连续冷却相变的影响。结果表明:Q420钢随着冷却速度的提高,奥氏体→铁素体开始转变温度Ar3降低,相变后铁素体晶粒细化;贝氏体开始转变温度(Bs)先升高后降低,贝氏体转变量逐渐增加。随着变形量的增加,CCT曲线整体向左上方移动,加速了铁素体和贝氏体相变。随着变形温度的降低,铁素体相变温度升高,扩大了铁素体区,贝氏体相变温度降低。更多还原

【Abstract】 In view of the process characteristics of Q420 ultra-heavy steel plate,the continuous cooling transformation behavior and microstructure evolution of the steel without and with deformation were simulated on a Gleeble-2000 thermomechanical simulator,the continuous cooling transformation( CCT) curves were plotted. The influence of cooling rate,deformation process on transformation was analyzed. The results show that with the increasing of cooling rate,the γ→α transformation temperature Ar3 is decreased,the grain size is refined; Bstemperature increases first and then decreases,but bainite content increases gradually. As the increasing of deformation,the bainite transformation and ferrite transformation are accelerated, CCT curves are shifted to left and upper. Ferrite transformation temperature is increased and bainite transition temperature is lowered as the decreasing of deformation temperature,and the ferrite region is expanded.更多还原