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通过温控拉伸试验、光学显微镜、X射线衍射技术和透射电镜分析了在298、373、473、573 K温度下变形时,20Mn24Cr5Al2Ni2TWIP钢的力学性能和显微组织变化规律。结果表明,TWIP钢的强度随变形温度的升高而降低,伸长率在373 K变形时比298 K变形显著下降;在373～573 K变形时伸长率有上升趋势;温度升高,组织中形变孪晶的数量减少,孪晶交叉现象减弱。研究TWIP钢的加工硬化行为表明,TWIP钢在拉伸过程中的加工硬化指数n值随真应变的增加而增加,在低应变区温度升高n值增加。在298～373 K变形时,形变孪晶占主导作用,在473～573 K变形时,形变孪晶和动态应变时效共同作用。
The mechanical properties and microstructure of 20Mn24Cr5Al2Ni2TWIP steel were analyzed by temperature-controlled tensile test, optical microscope, X-ray diffraction and transmission electron microscopy at 298, 373, 473 and 573 K. The results show that the strength of TWIP steel decreases with the increase of the deformation temperature, the elongation decreases obviously at 293 K when the elongation reaches 373 K, the elongation increases at 373 ~ 573 K, the temperature increases, Deformation in the twins reduced the number of twins crossing weakened. The study of work hardening behavior of TWIP steel shows that the value of work hardening index (n) of TWIP steel increases with the increase of true strain in the process of drawing, and the value of n in the low strain zone increases. At 298 ~ 373 K deformation, the deformation twins dominate. During the deformation of 473-573 K, deformation twins and dynamic strain aging act together.