Surface microstructure control of microalloyed steel during slab casting

作     者：Li-jun Xu Shu-lan Zhang Chun-gen Qiu Sheng-tao Qiu Xing-zhong Zhang 

作者机构：Central Iron and Steel Research InstituteBeijing 100081China 

出 版 物：《Journal of Iron and Steel Research International》 (国际钢铁研究杂志)

年 卷 期：2017年第24卷第8期

页      面：803-810页

核心收录：

学科分类：080602[工学-钢铁冶金] 08[工学] 0806[工学-冶金工程] 

主　　题：Microalloyed steel Surface intensive cooling Ferrite Carbonitride Crack 

摘      要：Lots of work has been done to investigate slab surface microstructure evolution during continuous casting in order to improve hot ductility and avoid transverse *** slab surface microstructure after continuous casting was characterized by optical microscopy,and the precipitation behavior was investigated by transmission electron *** the same time,the mechanical properties of the slabs were measured using a Gleeble 1500 Dthermal simulator and the transformation temperatures were examined by means of a thermal *** experimental results show that homogeneous microstructure without film-like ferrites and chain-like precipitates at grain boundary can be obtained through surface intensive cooling and transverse cracks do not occur on the slab *** the experimental steel,fine ferrite can form at slab surface when the water flow rate is larger than 1560L/min at vertical *** the distance to surface increases,microstructure turned to ferrite and ***,nano-size carbonitrides precipitated in the ferrite grain and the size was larger at the junction of the *** mechanical experiment results show that the hot ductility of the sample deformed at 650°C was better than that of the sample deformed at 750°*** reason is that filmlike ferrite formed at the grain boundary in the sample deformed at 750°***,the slab must be cooled quickly below Ar3 to prevent the occurrence of film-like ferrite and transverse cracks on the slab surface during casting.