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利用热模拟压缩变形试验研究了应变速率、形变温度和应变量对Ｑ２３５级别低碳２０钢过冷奥氏体形变强化相变的组织演变规律，探讨了奥氏体晶粒控制对形变强化相变的影响，分析了组织细化的原因、结果表明，形变强烈促进过冷奥氏体相变，过冷奥氏体在８００～７４０℃温度范围名义变形量为７０％，应变速率为１ｓ－１时,可获得平均截径为２～３μｍ及小于２μｍ的铁素体细晶与珠光体混合组织；还观察到在局部细小铁素体晶粒的晶界上渗碳体以离异珠光体形式析出的现象．适当控制奥氏体晶粒尺寸有利于形变强化细晶组织的获得．
The microstructure evolution of Q235-level low-carbon 20 steel under supercooled austenite transformation was studied by means of thermal simulation of compressive deformation. The effects of austenite grain control on deformation-enhanced phase transformation The results show that the deformation strongly promotes the subcooled austenite transformation. The nominal deformation of the supercooled austenite in the temperature range of 800-740 ℃ is 70% and the strain rate is 1s-1 , It is possible to obtain a mixed microstructure of fine ferrite and pearlite having an average diameter of 2 to 3 μm and less than 2 μm. It is also observed that cementite precipitates as a separate pearlite at grain boundaries of the local fine ferrite grains The phenomenon. Appropriate control of austenite grain size is conducive to obtaining the strain-enhanced fine grained structure.