摘要
基于动态大压下方法在1450热连轧机上生产出了510MPa强度级别超细晶粒热轧钢板。结果表明，通过基于动态大压下的热轧工艺，可以使Q235碳素钢的铁素体晶粒细化到4～6μm，可获得屈服强度为400MPa以上、抗拉强度510MPa以上强度级别的超细晶粒热轧钢板。超细晶粒热轧钢板的显微组织为铁素体和殊光体，铁素体晶粒多为细小均匀的等轴铁素体，铁素体晶粒内部及晶界位错密度较高，珠光体中的渗碳体大多以短棒状或颗粒状渗碳体存在。与用常规热轧工艺生产的Q235热轧钢板相比，基于动态大压下工艺生产的超细晶粒热轧钢板具有较高的强度和良好的韧性。
The 510 MPa ultra-fine grain hot rolling steel sheet were produce based on dynamic high pressuremethod in 1450 hot strip mill. The results show that ferrite grain size of Q235 carbon steel based on dynamic highpressure method can be fined to 4--6 μm, the yield strength and tensile strength of ultrafine grain steel sheets can ob-tained more than 400 MPa and 510 MPa respectively. The microstructure of ultrafine grain steel sheets are ferrite andpearlite, the ferrite is small and uniform equiaxed ferrite, the dislocation density is higher in ferrite grain boundary andintranular, the cementite in pearlite is mostly short rod or granular. Compared with Q235 hot rolled steel sheets pro-duced by conventional technology, ultra-fine grain steel sheets produced based on dynamic pressure technology hashigher strength and better toughness.
关键词
超细晶粒
热轧钢板
显微组织
力学性能
ultrafine grain, hot-rolled steel sheet, microstructure, mechanical properties
