不同温度退火后含铌钛IF钢的织构演变及其与塑性应变比和加工硬化指数的关系

对72%冷轧压下率的含铌钛IF钢分别进行790,850,910℃的连续退火处理,采用X射线衍射仪、拉伸试验机等对IF钢板不同厚度层的织构极密度与含量、塑性应变比、加工硬化指数进行了分析,研究了不同温度退火后织构的演变及其与塑性应变比和加工硬化指数的关系。结果表明:随着退火温度的升高,退火后IF钢中{001}〈110〉织构减弱,{111}〈112〉、{111}〈110〉织构均增强,且{111}〈110〉织构增强的速率比{111}〈112〉织构的快;不同温度退火后,IF钢中的织构沿厚度层均匀分布;随着退火温度的升高,{111}面织构增多,{100}面织构减少,{111}和{100}面织构体积比增大,塑性应变比呈非线性增加趋势,加工硬化指数变化不大;当退火温度为850℃时,塑性应变比各向异性系数最小,织构分布最均匀。

Texture Evolution and Its Relationship with Plastic Strain Ratio and Work Hardening Index of IF Steel Containing Nb and Ti after Annealed at Different Temperatures

The polar density and content of texture,plastic strain ratio and work hardening index of different thickness layers of IF steel plate containing Nb and Ti after continuous annealing at 790,850,910 ℃,which experienced cold rolling with reduction of 72%,were analyzed by X-ray diffractometer and tensile tester.The texture evolution and its relationship with plastic strain ratio and work hardening index after annealed at different temperatures were studied.The results show that with the increase of annealing temperature,the intensity of{001}〈110〉texture in IF steel after annealing decreased,while that of{111}〈112〉and{111}〈110〉textures increased;the increase rate of the intensity of{111}〈110〉texture was larger than that of{111}〈112〉texture.The texture distributed uniformly in different thickness layers of IF steel annealed at different temperatures.With the increase of annealing temperature,the content of{111}plane texture increased,while that of{100}plane texture decreased;the volume ratio of{111}and{100}plane texture increased;the plastic strain ratio increased nonlinearly,and the work hardening index changed little.When the annealing temperature was 850 ℃,the anisotropy coefficient of plastic strain ratio was the smallest,and the texture distribution was the most uniform.