Cause analysis and control of dark spot defects in hot-dip galvanized Si-Cr high strength duplex steel
YUAN Xiaoqian1, HE Xiaoqin1, ZHU Qimao1, ZHANG Liangliang2, WANG Shuokang1
1. Shougang Jingtang Iron & Steel Company, Tangshan 063200, China; 2. Research Institute of Technology, Shougang Group Co., Ltd., Beijing 100041, China
Abstract：By means of scanning electron microscope (SEM), energy spectrometer, glow analyzer (GDS), and three-dimensional morphology instrument (3D-OM), the causes of frequent dark spot defects in the production process of hot-dip galvanized Si-Cr series high strength steel in a factory were systematically analyzed. The results showed that the main causes of the dark spot defects were the uneven surface of galvanized sheet, the fluctuation of zinc layer, and the uneven surface enrichment of Si and Cr elements in the substrate. The unreasonable control of morphology and microstructure of oxide scale in hot rolling raw materials provided the conditions for the formation of dark spot defects. Through the adjustment of hot rolling coiling and cooling system, the structure and surface microstructure of the oxide scale could be improved, which effectively avoided the occurrence of dark spot defects.
苑小倩, 何小琴, 朱启茂, 张亮亮, 王硕康. 热镀锌Si-Cr系高强钢暗斑缺陷成因分析及控制[J]. 物理测试, 2024, 42(2): 50-55.
YUAN Xiaoqian, HE Xiaoqin, ZHU Qimao, ZHANG Liangliang, WANG Shuokang. Cause analysis and control of dark spot defects in hot-dip galvanized Si-Cr high strength duplex steel. PHYSICS EXAMINATION AND TESTING, 2024, 42(2): 50-55.
2024, Vol. 42 
