摘要
通过热膨胀及热压缩变形模拟连续冷却试验,绘制了高铝TRIP钢的CCT曲线,研究了连续冷却相变规律及热变形对相变的影响,并定性地分析了相变驱动力。结果表明,试验钢的CCT曲线主要分为3个区域,随着冷却速率的增大,铁素体和珠光体减少,贝氏体和马氏体增多,贝氏体从粒状逐渐转变为羽毛状和板条状。热变形使得高温奥氏体发生动态再结晶,原始奥氏体晶粒明显被细化,较高冷速下形成一些针状铁素体。热变形能提供更多的形核点,增大γ→α相变驱动力,缩短了贝氏体相变的孕育期,进而细化了室温组织。
Continuous cooling transformation curves,transformation law and the effect of hot deformation on transformation of a high aluminum TRIP steel were studied by means of thermal dilation test and hot-compressing thermal simulation test.In addition,the driving force of transformation was qualitatively analyzed.The results show that the CCT curves can be divided into three regions.With the cooling rate increasing,the volume fractions of ferrite and pearlite decrease,the volume fractions of bainite and martensite increase,respectively.The shape of bainite transforms from granular to feather-like or lath-like.As a result of dynamic recrystallization caused by hot deformation,the original austenite grain of the samples is refined and acicular ferrite is observed at high cooling rates.Hot deformation can provide more nucleation sites and higher driving force of γ→α transformation,thus resulting in a shorter bainite transformation incubation period and a finer the room temperature microstructure.
作者
黄慧强
邸洪双
龚殿尧
Huang Huiqiang;Di Hongshuang;Gong Dianyao(State Key Laboratory of Rolling and Automation,Northeastern University,Shenyang Liaoning 110819,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2020年第6期84-88,共5页
Heat Treatment of Metals