铸态超级双相不锈钢S32750热变形行为及组织演变  

Hot Deformation and Microstructure Evolution of As-Cast Super Duplex Stainless Steel S32750

作　　者：武敏 李建春[2] 李国平[2] 卫英慧[1] Wu Min;Li Jianchun;Li Guoping;Wei Yinghui(College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan 030024;Technical Center,Shanxi Taigang Stainless Steel Co Ltd,Taiyuan 030003)

机构地区：[1]太原理工大学材料科学与工程学院,太原030024 [2]山西太钢不锈钢股份有限公司技术中心,太原030003

出　　处：《特殊钢》2019年第5期12-16,共5页Special Steel

基　　金：国家重点研发计划(2016YFB0300201);山西省科技重大专项(20181101015)

摘　　要：通过Gleeble-3800热压缩实验研究了铸态超级双相不锈钢S32750(/%:0.017C,0.53Si,0.93Mn,0.023P,0.001S,25.58Cr,7.00Ni,4.03Mo,0.28N)在变形温度为950~1 200℃、应变速率为0.1~25/s、真应变为1条件下的热变形行为与组织演变规律。结果表明,超级双相不锈钢S32750热变形行为受变形温度和应变速率的影响明显。在950~1 050℃、0.1/s变形时,流变曲线表现出"类屈服平台"特征;当变形温度为1100~1 200或应变速率为10/s、25/s时,流变曲线为典型的动态再结晶特征。对其微观组织进行观察发现,铁素体在各变形条件下均发生动态再结晶;奥氏体在950℃和1 200℃时基本不受应变速率影响,前者发生动态回复,后者发生动态再结晶。而在1 050℃时,受应变速率影响较大:小应变速率下(0.1/s)下发生动态回复,大应变速率下(10/s)发生动态再结晶。The hot deformation and microstructure evolution of as-cast S32750 super duplex stainless steel(/%:0.017 C,0.53 Si,0.93 Mn,0.023 P,0.001 S,25.58 Cr,7.00 Ni,4.03 Mo,0.28 N)are investigated at different temperatures(950~1 200℃),strain rates(0.1~25/s)and strain(1)by Gleeble-3800 thermo-mechanical simulator.The results shows that the hot deformation behavior of S32750 was considerably affected by temperature and strain rate.The flow curves exhibit particularly yield-point-elongation-like effect at temperatures of 950~1050℃and strain rate of 0.1/s,which is characterized by a non-strengthening plateau during the initial stages of plastic deformation.The flow curves show the dynamic recrystallization characteristic at temperatures of 1 100~1 200℃or at strain rates 10/s、25/s.It is found that dynamic recrystallization occurs in ferrite at different deformation conditions.Whereas austenite undergoes dynamic recovery at950℃and dynamic recrystallization at 1 200℃,and the strain rate has a minimal effect on the microstructure evolution of austenite;when the deformation temperature is 1 050℃,the strain rate plays an important role in the softening process,the austenite undergoes dynamic recovery at strain rate of 0.1/s and dynamic recrystallization at 10/s.

关 键 词：超级双相不锈钢S32750 真应变-真应力曲线 动态回复 动态再结晶 

分 类 号：TG142.71[一般工业技术—材料科学与工程] TG156[金属学及工艺—金属材料]