低碳Cr-Mo系深冲双相钢组织与织构演变

Microstructure and Texture Evolution of Low-carbon Cr-Mo Deep Drawing Dual-phase Steel

通过组织观察以及TEM与XRD技术研究了低碳Cr-Mo系深冲双相钢组织与织构演变规律。结果表明:奥氏体未再结晶区终轧有利于形成{112}〈111〉织构,冷轧过程中{001}〈110〉,{112}〈110〉与{223}〈110〉织构稳定增加,退火过程中形成有利于深冲性能的〈111〉//ND以及{554}〈225〉与{332}〈113〉织构;820℃与860℃临界区退火后γ纤维织构密度差异较小,但是高温退火增大{111}〈110〉与{111}〈112〉织构的取向密度差值,归因于贝氏体中的固溶碳以及贝氏体相变时的变体选择;高温卷取能诱发热轧板中Mo基碳化物粒子析出,并在退火保温过程中回溶,既能发展再结晶织构,又能促进第二相形成。

Microstructure and texture evolution of low-carbon Cr-Mo deep drawing dual-phase steel were investigated by using microstructure observation,TEM and XRD.The results show that,the finish-rolling process conducted in austenite no-recrystallization zone promoted the formation of {112}〈111〉 component.The intensity of {001}〈110〉,{112}〈110〉 and {223}〈110〉 orientations were steadily enhanced during cold rolling.The formation of sharper 〈111〉//ND,{554}〈225〉 and {332}〈113〉 textures during annealing was favorable to improve the deep draw-ability of dual-phase steel.When intercritical annealed at 820℃ and 860℃,the intensity of γ-fibre was slightly different.The difference of intensity between {111}〈110〉 and {111}〈112〉 texture tended to increase at high-temperature annealing,causing by the solution-carbon of bainite and the variant selection from austenite to bainite.The high-temperature coiling process induced precipitation of Mo-based carbide in hot-rolled strips,and re-dissolution during the holding stage in annealing process,which not only facilitated the formation of recrystallization textures,but also improved the second phase transformation.