热镀锌铁合金双相钢表面白条缺陷分析

Analysis of white strip defects on the coating surface of hot-dip galvannealed DP steel

分析了热镀锌铁合金双相钢两种白条缺陷的微观形貌及其特征,并对相关工艺进行了讨论。结果表明:两种白条缺陷都源自于镀锌前的基板表面缺陷,一种源自热轧辊系铁皮,其微观以Mo、V、Cr、Ni等热轧辊系元素为特征;另一种推测源自铸坯微裂纹,其微观特征主要为二次氧化物。

The microstructure and characteristics of two types of white stripe defects in hot-dip galvannealed DP steel were studied,and the relevant processes were analyzed and discussed.The results show that both types of white strip defects originate from the surface defects of the substrate before galvanizing.One originates from the iron scale of the finishing roller,with its microstructure characterized by characteristic elements Mo,V,Cr,Ni,etc.Another type originates from microcracks in the casting slab,whose microscopic characteristics are mainly secondary oxides.