TRIP钢动态拉伸行为的残余奥氏体转变相关性研究

Relationship between Transformation of Retained Austenite and Dynamic Tensile Behavior of TRIP Steel

对两种商业化TRIP钢进行双相化处理，获得了与TRIP钢中铁索体量相当的DP钢．采用气动式间接杆杆型冲击拉伸试验装置对TRIP钢和DP钢在10^2-10^3s^-1应变率范围的动态拉伸变形行为进行了研究．结果显示，在所有应变率下，两种TRIP钢的动态拉伸强度略低于DP钢，而延伸率却大大高于DP钢．断裂试样的SEM观察表明，残余奥氏体的变形诱发相变显著延迟了TRIP钢的微孔洞的形成，持续抑制微孔洞的生长．

Two commercial TRIP steels were heat treated to produce DP steels whose ferrite content was equal to that of original TRIP steels. The dynamic tensile test was carried out on both DP and TRIP steel samples with strain rates in the range of 10^2 - 10^3 s^- 1 . A pneumatic indirect bar-bar tensile impact tester was employed in the present work. The results indicate that under all strain rates, the tensile strengths of two TRIP steels are slightly lower than that of two DP steels, and their elongations are much higher than that of DP steels. Further analysis on the formation and growth of micro-void by SEM proves that transformation of retained austenite during deformation remarkably postpones the micro-void formation in TRIP steels, and restrains the growth of micro-voids.