Analysis and control for bright spot defect on surface of hot galvanized steel sheet
LI Wei- gang1，ZHAO Yun- long1，WANG Teng1，ZHOU Zhong- chen1，QIAN Xin2
1. Technology Center， Ma′anshan Iron and Steel Co., Ltd.， Ma′anshan 243000， Anhui， China 2. Cold Rolling General Plant， Ma′anshan Iron and Steel Co., Ltd.， Ma′anshan 243000， Anhui， China
Abstract：By using the optical microscope and scanning electron microscope, the microelements and micromorphology of the surface bright spot of hot galvanized steel sheet were analyzed. The results showed that there were pits on the surface bright spot, which had three micromorphologies of the round, oval and elongated, and Fe element enrichment at the defect. Parts of the inhibition layer were broken, and the thinner inhibition layer promoted the generation of brittle Fe- Zn phase and decreased the adhesion of the zinc layer in the defect region. Combined with the specific circumstances, the material factors, annealing furnace, zinc pot area, and finishing area were investigated. The results showed that the spot defects were related to the adhesion and detachment of cadmia on the steel strip surface, and adjusting the technological parameters of the gas knife can improve the defect.
李伟刚 赵云龙 王滕 周忠臣 钱鑫. 热镀锌钢板表面亮点缺陷成因分析与控制[J]. 中国冶金, 2018, 28(10): 46-50.
LI Wei- gang，ZHAO Yun- long，WANG Teng，ZHOU Zhong- chen，QIAN Xin. Analysis and control for bright spot defect on surface of hot galvanized steel sheet[J]. China Metallurgy, 2018, 28(10): 46-50.
2018, Vol. 28 
