Investigation on the cold-strip breakage of SUS445J2 ultra-pure ferritic stainless steel during rolling process  

作　　者：CHEN Xu DONG Wenbo 

机构地区：[1]Research Institute,Baoshan Iron&Steel Co.,Ltd.,Shanghai 201999,China

出　　处：《Baosteel Technical Research》2021年第1期17-23,共7页宝钢技术研究（英文版）

摘　　要：In this work,the cause of the cold-strip breakage of SUS445J2 ultra-pure ferritic stainless steel was investigated using optical microscopy,energy dispersive spectroscopy,and electron backscatter diffraction technique.Results show that during cold rolling,the breakage of the stainless steel strip was mainly caused by massive niobium-rich(Nb-rich)carbides present in the center of the strip.Furthermore,cracks initiated at these carbides in the central layer.The massive carbide precipitates resulted from the segregation and enrichment of Nb,titanium(Ti),and carbon(C)in the central layer during the subsequent solidification stage of SUS445J2 stainless steel.Additionally,the banded structure and coarse ferrite grains in the central layer reduced the plasticity of the material,causing cracks to propagate along these grains and finally leading to cold-strip breakage.By reducing the solidification cooling rate of the billet,increasing the pouring temperature,discretizing Nb,Ti,and C enrichment via electromagnetic stirring,and forming equiaxed crystals in the central layer,the precipitation of harmful massive Nb-rich carbides in the central layer could be effectively avoided.

关 键 词：SUS445J2 strip breakage Nb-rich carbides MICROSTRUCTURE 

分 类 号：TG335[金属学及工艺—金属压力加工]