摘要
使用室温拉伸和高温拉伸实现了304奥氏体不锈钢不同应变率及不同温度下的拉伸塑性变形,使用铁素体测量仪、XRD等分析手段测试了不同应变率、不同组织状况及不同温度下的形变诱导马氏体转变量.结果表明,形变诱导马氏体的转变量与应变率、组织均匀度及变形温度三种因素有关,室温形变时,随着塑性变形率的增加,马氏体转变量逐渐上升;对于室温下周向变形率为30%的内高压成形环焊缝拼焊管而言,母材、热影响区和焊缝处的马氏体转变量依次呈上升趋势,组织均匀性越差,马氏体的转变量越高;高温拉伸时,随着环境温度的上升,马氏体的转变量呈下降趋势,在275℃时,马氏体的转变量趋近为0.
Tensile tests of SUS304 stainless steel specimens were performed with different strain rates at different temperatures.Moreover,the martensite induced by deformation was analyzed by ferrite measuring instrument,optical microscopy and XRD.Experimental results show that the transformation of martensite is closely related to uniformity of microstructure,strain rate and temperature.At room temperature,the amount of martensite induced by deformation increases with the increasing of tensile strain.For the tailor-welded tube endured 30% circumference strain in hydroforming process at temperature,the amount of martensite is higher in fusion zone than that in HAZ,and it is fewer in the base metal,i.e.,the higher the uniformity,the less the amount of martensite transformation induced by deformation from austenite.The amount of martensite decreases with the increasing of testing temperature.Tensile tests at 275 ℃ indicated that martensite transformation induced by deformation can be restrained in the process of plastic deformation at this temperature,the volume fraction of martensite is almost 0 under such conditions.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2012年第12期89-92,117,共4页
Transactions of The China Welding Institution
关键词
形变诱导马氏体相变
应变率
组织均匀性
温度
影响因素
deformation induced martensitic transformation
strain rate
microstructure heterogeneity
temperature
influencing factor
