汽车高强钢簇状翘皮缺陷成因分析及控制  

Cause analysis and control of cluster blister defect in automobile high strength steel

作　　者：倪有金[1] 朱克然 龚坚[1] 黄福祥 亢小敏[2] 吴友谊 王彦峰 陈瑾[2] NI Youjin;ZHU Keran;GONG Jian;HUANG Fuxiang;KANG Xiaomin;WU Youyi;WANG Yanfeng;CHEN Jin(Qianshun Technology Center,Beijing Shougang Co.,Ltd.,Tangshan 064400,Hebei,China;Manufacturing Department,Beijing Shougang Co.,Ltd.,Tangshan 064400,Hebei,China;Steelmaking Department,Beijing Shougang Co.,Ltd.,Tangshan 064400,Hebei,China)

机构地区：[1]北京首钢股份有限公司迁顺技术中心,河北唐山064400 [2]北京首钢股份有限公司制造部,河北唐山064400 [3]北京首钢股份有限公司炼钢作业部,河北唐山064400

出　　处：《中国冶金》2024年第8期99-106,共8页China Metallurgy

摘　　要：为了减少590 MPa级别汽车高强钢板表面簇状翘皮缺陷,对该缺陷的成因和机制进行了分析和调查。结果表明,该缺陷起源于铸坯上表面宽度1/4和3/4区域的皮下微裂纹,此类包晶高Nb钢和中高铝钢对裂纹较为敏感的主要原因是NbCN和AlN在矫直区温度下大量析出造成晶界脆化,包晶钢凝固坯壳不均匀和高铝钢由于渣-钢变性反应导致的深振痕加大了应力集中和裂纹敏感性。结合钢种凝固特性,分别采取了控制钢水N元素质量分数不高于0.0040%、按w([Ti])/w([N])=4~5添加Ti、设计开发新型保护渣以及优化连铸工艺等措施,裂纹指数由12~20个/m降低到0.03~0.20个/m,簇状翘皮缺陷发生率由29.8%降低到0.5%以下。In order to reduce the cluster blister surface defect of 59o MPa grade automobile high strength steel plate,the causes and mechanism of the defect were analyzed and investigated.The results show that the defect originates from the subsurface micro-cracks of the billet which locates in the area of 1/4 and 3/4 width of the upper surface.The main reasons why these kinds of steel are more sensitive to cracks are that the precipitation of NbCN and AIN under the temperature of straightening zone causes grain boundary embrittlement in Nb-containing peritectic steel and high alumina steel.Uneven solidification shell of peritectic steel and deep oscillation marks of high aluminum steel caused by slag-steel modification reaction further increase the stress concentration and crack sensitivity.Ac-cording to the solidification characteristics of steel,measures were taken respectively,such as controlling mass frac-tion of N element in molten steel not higher than 0.0040%,adding Ti according to w([Ti])/w([N])=4-5,desig-ning and developing new mold slag,and optimizing the continuous casting process.The number of cracks per meter decreases from 12-20 to 0.03-0.20,and the incidence rate of cluster blister is reduced from 29.8%to less than 0.5%.

关 键 词：高强钢 簇状翘皮 裂纹 晶界脆化 析出物 深振痕 

分 类 号：TF777[冶金工程—钢铁冶金]