摘要
Abstract
During the production of automotive-grade steel DC51D+Z on a modified Sendzi-mir galvanizing line,defects caused by foreign particle embedment were observed.The defects ex-hibited a non-concentrated distribution without periodicity.Through analysis employing scanning electron microscopy(SEM)and metallographic examination,the foreign particles were identified as contaminants such as iron powder and oil residues.Further investigation revealed that these impuri-ties primarily originated from residual iron powder and oil on the strip surface,as well as reduced ox-ides formed during strip oxidation in the no oxidation furnace(NOF)section.These contaminants adhered to furnace rolls,forming buildups.Due to rapid heating during automotive steel production,the adhesion strength of the roll buildups decreased,causing them to transfer onto the strip and sub-sequently enter downstream processes.The foreign particles were carried into the zinc pot,resulting in galvanizing defects,and were ultimately pressed into the strip surface during skin-pass rolling,forming the observed embedment defects.关键词
异物压入/炉辊结瘤/高温/清洗Key words
foreign material indentation/furnace roller nodules/high temperature/cleaning分类
金属材料
