321奥氏体不锈钢动态再结晶的研究

通过Gleeble-1500热模拟试验机研究了321钢(/%:0.028C、0.69Si、1.21Mn、0.030P、0.001S、17.33Cr、9.19Ni、0.31Ti)单道次高温(900～1 200℃)压缩(0.01～1 s^-1)时的动态再结晶。结果表明,变形温度越高,应变速率越低,321钢的软化作用越强,热变形条件下的真应力-真应变曲线一般没有明显的应力峰值,在应变速率0.01、0.1、1 s^-1时321钢动态再结晶开始发生的温度分别为1 050、1 150、1 150℃;在1 200℃变形时,仍然只发生部分动态再结晶。321钢热变形激活能Q=422.72 kJ/mol,动态再结晶Z参数Z=εexp[422 720/(RT)],临界应变ε_c=0.035 67Z^{0.066 04}。

A Study on Dynamic Recrystallization of Austenite Stainless Steel 321

The dynamic recrystallization of steel 321 (/% : 0. 028C, 0. 69Si, 1. 21Mn, 0. 030P, 0. 001S, 17. 33Cr,9. 19Ni, 0. 31Ti) has been studied by single pass hot compression with 0. 01 ~ 1 s^-1 at 900 ~ 1 200 ℃ oh a Gleeble-1500 thermal simulation machine. Results show that with higher deformation temperature and lower strain rate, the softening effect of steel 321 is stronger； generally there is no obvious peak stress at hot deformation true stress-true strain curves ； with strain rate 0. 01, 0. 1 and Is-1, the temperature of initial dynamic recrystallization for steel 321 is respectively 1 050 °C , 1 150 ℃ and 1 150 ℃，and as deforming at 1 200 ℃, the partial dynamic recrystallization only occurs in steel. The activation energy Q for dynamic recrystallization in hot deformation process of steel 321 is 422. 72 kJ/mol, the dynamic recrystallization Z parameter is εexp[422 720/ (RT) ] and critical strain ε_c =0.035 67Z^{0.066 04}.