热镀锌双相钢氧化斑问题分析与工艺优化  

Analysis and Optimization for Oxidized Spot Defects on the Surface of Hot Galvanized Dual-phase Steel

作　　者：刘学良 贾冬梅 张鹏 LIU Xueliang;JIA Dongmei;ZHANG Peng(Valin ArcelorMittal Automotive Steel Co.,Ltd.,Loudi 417000,China)

机构地区：[1]华菱安赛乐米塔尔汽车板有限公司,湖南娄底417000

出　　处：《金属材料与冶金工程》2024年第3期13-17,共5页Metal Materials and Metallurgy Engineering

摘　　要：采用扫描电子显微镜对缺陷区域进行表面及截面形貌表征和能谱分析,研究热镀锌双相钢表面氧化斑缺陷的形成机理。结果表明:双相钢基体Mn、Si等元素的表面富集,弱化锌液在带钢表面的粘附性能,镀层表面形成带少量黑点的簇状氧化斑;炉鼻内腔Zn O颗粒掉进锌锅,在锌液表面形成的薄膜先于锌液粘附带钢基体,并部分延伸至镀层表面,进一步促进镀层簇状氧化斑的形成。在实际生产中,通过优化退火炉保护气氛压力和H2含量、炉鼻子加湿和排锌工艺等措施,热镀锌双相钢镀层氧化斑缺陷得到了有效控制,缺陷发生率由11%以上降低至5%以内。Surface and cross-sectional morphology characterization and energy spectrum analysis of the defects area were conducted by scanning electron microscopy,and the formation mechanism of oxidized spot defects on the surface of hot galvanized dual-phase steel was discussed.The results show that the surface enrichment of Mn,Si and other elements in the substrate weakens the adhesion property of zinc liquid on the surface of strip,and clusters of oxidized spots with a few black spots formed on the coating surface;when ZnO particles fall into zinc pot from the cavity of furnace snout,thin films formed on the surface of zinc liquid,which adhere to the surface of strip before zinc liquid,and thin films partly extend to the coating surface,which further promotes the formation of oxidized spots.During practical production,technological measures are adopted such as optimizing annealing furnace protective atmosphere pressure and H,content and the furnace snout process of humidifying and zinc liquid pumping,and oxidized spot defects on the surface of galvanized dual-phase steel have been effectively controlled,and the defects occurrence rate is reduced from more than 11%to less than 5%.

关 键 词：热镀锌 双相钢 氧化斑 富集 粘附性 

分 类 号：TG174.443[金属学及工艺—金属表面处理]