Abstract： In order to solve the problem of more folding and scratching in the hot rolling process of Q420B largesize angle steel， the numerical simulation method is used to study the deformation characteristics of W butterfly type. By modifying the hole profile of the fifth pass of the W butterfly type， the surface quality problems in the production process of largesize angle steel have been significantly improved. The results show that a larger size of angle steel can be rolled out with a smaller billet by the Wpass system，but the angle steel needs to be bent several times for the Wpass system. Due to the violent metal flow on the surface，the steel is easy to produce surface quality defects. When the W butterfly pass is used to roll the No.22 angle steel，the fold tends to occur in the sixth pass. After the pass optimization，the rates of scratches and folding defects are obviously reduced.
张宏亮，冯光宏，崔怀周. 大规格Q420B热轧角钢轧制中间道次开裂缺陷分析[J]. 钢铁, 2019, 54(9): 73-78.
ZHANG Hongliang，FENG Guanghong，CUI Huaizhou. Analysis of crack defects in Q420B angle steel #br#
during hot rolling process. Iron and Steel, 2019, 54(9): 73-78.
