0Cr17Mn17Mo3NiN奥氏体不锈钢的热变形行为及热加工图

Hot Deformation Behavior and Processing Map of 0Cr17Mn17Mo3NiN Austenitic Stainless Steel

采用Gleeble-3500热模拟试验机研究0Cr17Mn17Mo3Ni N奥氏体不锈钢在950~1 100℃,0.01~1 s-1条件下的热变形行为。依据热压缩过程中0Cr17Mn17Mo3Ni N奥氏体不锈钢的真应变-真应力曲线,确定了其在该热变形参数下的高温本构方程,并根据动态材料模型建立热加工图。结果表明,在相同的应变速率下,流变应力随着温度的升高而降低;而在相同的变形温度下,流变应力随着应变速率的减小而降低。0Cr17Mn17Mo3Ni N奥氏体不锈钢的热变形激活能为549 k J/mol。在980~1 050℃范围内,真应变为0.4,应变速率为0.01~0.1 s-1时,能量耗散效率η值为0.28~0.3,0Cr17Mn17Mo3Ni N奥氏体不锈钢容易发生动态再结晶。因此,该温度区域是最优的热加工工艺窗口。

The hot deformation behavior of 0 Cr17 Mn17 Mo3 Ni N austenitic stainless steel is investigated by Gleeble-3500 in the temperatures range of 950-1 100 ℃ and strain rates range of 0.01-1 s^-1. The constitutive equation of this stainless steel under hot deformation is determined according to the true strain-true stress curves. The processing map is established on the basis of the dynamic material model（DMM）. The results show that the flow stress decreases with the increase of the temperature at the same strain rate; however, the flow stress decreases with decrease of the strain rate at the same temperature. The activation energy of hot deformation for the austenitic stainless steel is 549 k J/mol. The energy dissipation efficiency is 0.28-0.3 in the temperature of 980-1 050 ℃, when the true strain is 0.4 and the the strain rate is 0.01-0.1 s^-1. The optimized hot deformation processing window of the austenitic stainless steel is identified as 980-1 050 ℃, 0.01-0.1 s^-1, in which the dynamic recrystallization in the stainless steel is easily occurred.