%A YANG Qi-jun, YANG Geng-chao, LIU Jian, WANG Xu-ji, ZHAO Yang %T Mechanism and prevention of internal crack generation of 52CrMoV4 continuous casting slab for spring flat steel %0 Journal Article %D 2023 %J CONTINUOUS CASTING %R 10.13228/j.boyuan.issn1005-4006.20220078 %P 41-46 %V 42 %N 1 %U {http://www.chinamet.cn/Jweb_lz/CN/abstract/article_154138.shtml} %8 2023-02-18 %X The quality of continuous casting slab is directly related to the subsequent rolling process and the quality of medium and heavy plates. In this paper, the causes of the internal crack of 52CrMoV4 continuous casting slab for spring flat steel were analyzed by means of macrostructure inspection, microstructure observation and composition analysis. The results showed that the central segregation of Cr, Mn and Mo in the continuous casting slab caused martensitic transformation and large tensile stress during the cooling process, which was the main reason for the central crack of the 52CrMoV4 continuous casting slab. After increasing the purity of molten steel, reducing the pouring temperature and casting speed, increasing the electromagnetic stirring force as well as increasing the mass fraction of N during smelting, the crack defects in the center of the 52CrMoV4 steel slab were eliminated and the quality of the center of the slab was effectively improved. As a result, the quality of the center in the hot-rolled spring flat steel was good and fully met the requirements of customers.