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.