27SiMn钢圆铸坯的心部裂纹分析  

Analysis of Cracks in Core of 27SiMn Steel Round Billet

作　　者：张娜[1,2] 李智丽 董丽丽[1] 石龙 ZHANG Na;LI Zhili;DONG Lili;SHI Long(Technical Center of Inner Mongolia Baotou Steel Union Co.,Ltd.,Baotou 014010,China;Inner Mongolia Enterprise Key Laboratory of Rare Earth Steel Products Research&Development,Baotou 014010,China;Steel Tube Co.,Inner Mongolia Baotou Steel Union Co.,Ltd.,Baotou 014010,China)

机构地区：[1]内蒙古包钢钢联股份有限公司技术中心,内蒙古包头014010 [2]内蒙古自治区稀土钢产品研发企业重点实验室,内蒙古包头014010 [3]内蒙古包钢钢联股份有限公司钢管公司,内蒙古包头014010

出　　处：《热加工工艺》2022年第19期145-148,144,共5页Hot Working Technology

摘　　要：从铸坯的成分、宏观形貌、微观断口、析出物、凝固组织等对27SiMn钢圆铸坯心部裂纹缺陷进行检测分析。结果表明:27SiMn圆铸坯凝固末期,心部补缩不足形成疏松、缩孔缺陷;S、Mn等元素在金属自由表面上富集析出,形成卵形树枝晶,降低组织的连续性而产生裂纹,后续过程应力释放使裂纹进一步扩展,形成星形裂纹。通过控制浇钢温度、降低二冷区水量、降低拉速等工艺参数,有效地消除了27SiMn圆铸坯心部星形裂纹缺陷,提高了该钢种大断面连铸坯的成材率。From the composition, macroscopic morphology, micro-fracture, precipitates and solidification structure of the billet, the crack defects in the core of 27SiMn steel round billet were detected and analyzed. The results show that at the end of solidification of 27SiMn round billet, the defects of shrinkage porosity and shrinkage holes are formed due to insufficient feeding at the core;S, Mn and other elements are enriched and precipitated on the free surface of the metal to form ovate dendrites, which reduces the continuity of the microstructure and produce cracks. The stress release during subsequent process makes the cracks further expand and form star cracks. By controlling the casting temperature, reducing the water volume in secondary cooling zone and pulling speed, the star crack defects in the core of 27SiMn round billet are effectively eliminated,and the yield of the cotinuous casting billet with large section is improved.

关 键 词：27SIMN钢 圆铸坯 星形裂纹 消除 

分 类 号：TG245[金属学及工艺—铸造]