双相钢表面山峰纹问题分析与控制

在生产过程中,热镀锌双相钢表面出现明显的山峰纹缺陷,严重影响热镀锌双相钢产品的表面质量。缺陷处有漏镀、锌层不均和抑制层形成不良等特征,基板表层有脱碳及微裂纹、表层毛刺突起等现象。通过分析认为,基板表层微裂纹是造成热镀锌双相钢表面山峰纹的根本原因。采用低温快烧的加热制度,适当降低轧制温度,合理控制除鳞及酸洗工艺,降低热卷厚度以降低冷轧压下率,可有效控制冷轧板浅表层微裂纹的形成,从而有效解决热镀锌双相钢表面山峰纹问题。

Analysis and control of mountain-like surface defects of dual phase steel

Mountain-like defect was obviously found on the surface of the zinc layer during the galvanizing process of hot dip galvanized dual phase steel，which had very bad effect on the surface quality. There were the pretermission of plating，uneven zinc layer，and low-quality inhibition layer in the defect area，and the decarbonization，the microcracks and the burr were found on the substrate surface. Based on the analysis，the microcracks on the substrate surface were the basic reason for the mountain-like defect on the surface of hot dip galvanized dual phase steel. The microcracks of superficial zone in cold rolled sheet can be effective controlled by rapid heating with the lower target temperature，reducing the rolling temperature properly，decreasing the hot rolling thickness and the cold rolling reduction，and reasonably controlling the descaling and pickling process，which can solve the problem of the mountain-like defect on hot dip galvanized dual phase steel.