包晶合金钢厚板边裂机理分析与控制  

Analysis and control of edge crack on thick plate in peritectic alloyed steel

作　　者：顾晔 郭亮亮[2] 刘自成[1] GU Ye;GUO Liangliang;LIU Zicheng(Heavy Plate Business Unit,Baoshan Iron&Steel Co.,Ltd.,Shanghai 200941,China;Research Institute,Baoshan Iron&Steel Co.,Ltd.,Shanghai 201999,China)

机构地区：[1]宝山钢铁股份有限公司厚板事业部,上海200941 [2]宝山钢铁股份有限公司中央研究院,上海201999

出　　处：《宝钢技术》2023年第3期34-39,共6页Baosteel Technology

摘　　要：通过对包晶合金钢厚板边裂缺陷系统研究,发现该缺陷与铸坯横向裂纹关系密切。采用金相显微镜、扫描电镜、热—力模拟试验机、激光共聚焦显微镜,分析了包晶合金钢的材料特性、析出相行为、裂纹断裂机制等。研究结果表明:碳质量分数在0.080%~0.150%的包晶反应导致较大的体积收缩,裂纹敏感性强。包晶合金钢中有大量分布于晶界的TiN和Nb(C,N)析出相;随着包晶合金钢连铸冷却进程,析出相脆化了奥氏体晶界,增加了裂纹倾向性。通过控制钢种化学成分、优化二冷工艺等措施,显著改善了包晶合金钢厚板边裂缺陷。In this study,the edge crack on the thick plate in peritectic alloyed steel,which is mainly caused by transverse cracks of continuous casting slab,has been discussed.The material properties,precipitation behaviors,and thermal simulation fracture mechanism of peritectic alloyed steel were analyzed systematically by metallographic microscope,scanning electron microscope,thermo-mechanical simulator,and laser scanning confocal microscopy.The results show that the peritectic reaction with a carbon mass fraction of 0.080%~0.150%leads to significant volumetric contraction and strong surface cracking.Meanwhile,there are a large number of precipitates,such as TiN and Nb(C,N),in the as-cast grain boundary of peritectic alloyed steel.With the continuous casting cooling process of peritectic alloy steel,the precipitated phase embrittles the as-cast grain boundary and increases the crack tendency.By controlling the chemical elements and optimizing the secondary cooling process,the edge cracking defect of the thick plate of peritectic alloy steel was improved significantly.

关 键 词：边裂 横向裂纹 析出相 包晶合金钢 连铸 

分 类 号：TG142.33[一般工业技术—材料科学与工程]