Abstract:There were cross striation defects on IF steel after cold rolling,continuation annealing and pressing which seriously affected the use. After inquiry and analysis of the original chemical composition and the hot rolling process parameters of the normal and detected steel,the results showed that the chemical composition of the steel met there quirements and the hot rolling process parameters were normal. The surface fine-grains microstructure and surface carbonization were discovered on the defected sample,therefore there was a yield platform in the tensile test. Through the whole process inspection of hot rolling,cold rolling and annealing,it was found that the surface carburization was caused by a large amount of grease in the furnace wall andchamber during annealing,the sum of C and N content were as high as 80×10-6,Ti element could not convert all the C and N interstitial atoms into Ti carbonitride,so the yield platform was appeared and reslute in cross striation on the surface of the steel during pressing. Through regular cleaning of grease on furnace wall and modification of equipment such as water vapor feeding into furnace chamber,the defects of yield platform and pressing cross striation were eliminated.
刘兰霄,陈凌峰,关建东,吴耐,周娜,刘娟. IF钢表面横纹缺陷分析[J]. 物理测试, 2019, 37(5): 51-55.
LIU Lan-xiao,CHEN Ling-feng,GUAN Jian-dong,WU Nai,ZHOU Na,LIU Juan. Analysis of cross striation on the surface of IFsteel. PHYSICS EXAMINATION AND TESTING, 2019, 37(5): 51-55.