超高强度不锈钢热变形行为及加工图

Hot deformation behavior and processing map of ultra-high strength stainless steel

采用Thermecmaster-Z热模拟试验机对10Cr13Co13Mo5Ni3W1VE(S280)超高强度不锈钢进行变形温度800~1150℃、应变速率0.001~10 s^(−1)、压下率70%条件下的等温恒应变速率压缩实验,分析其热变形行为,并构建基于Murty失稳准则的加工图。结果表明:S280超高强度不锈钢的流变应力对变形温度和应变速率较为敏感,随应变速率增加和变形温度降低,流变应力显著升高。通过加工图分析和变形微观组织观察,S280超高强度不锈钢的失稳变形工艺窗口为800~1040℃、0.06~10 s^(−1),对应的塑性变形机制主要为局部流动;较佳的变形工艺窗口为1095~1150℃、0.001~0.04 s^(−1);最佳变形工艺参数在1125℃、0.001 s^(−1)附近,对应的塑性变形机制主要为动态再结晶。

The 10Cr13Co13Mo5Ni3W1VE(S280)ultra-high strength stainless steel was subjected to isothermal and constant strain rate compression experiments at deformation temperature of 800-1150°C,the strain rate of 0.001-10 s^(–1),and the deformation amount of 70%by using Thermecmaster-Z thermal simulation testing machine.The hot deformation behavior of the steel was analyzed,and the processing maps based on Murty instability criterion were established.The results show that the flow stress of S280 ultra-high strength stainless steel during hot deformation is sensitive to deformation temperature and strain rate.With the increase of strain rate and the decrease of deformation temperature,the flow stress increases significantly.It is determined that the region of instability occurs in the temperature range of 800-1040°C and strain rate range of 0.06-10 s^(–1),and the corresponding instability deformation mechanism is mainly flow localization.The desired parameters are 1095-1150℃and 0.001-0.04 s^(–1) with the plastic deformation mechanism of dynamic recrystallization,and the optimum parameters are around 1125℃ and 0.001 s^(–1).