热轧钢卷平整生产线挫伤缺陷的原因分析

Analysis of Scratch in Flatening of Hot Rolled Strip Coil

随着用户对热轧钢带板形质量要求的不断提高,热轧带平整工序在板形质量改善中的应用越来越多。但是,热轧平整工序也带来了大量的表面质量缺陷,以挫伤缺陷出现最为广泛,对板带表面质量影响最为严重。通过对挫伤缺陷形貌的分析,提出挫伤缺陷是由相互挤压的带钢的相对滑动导致局部金属产生剪切滑移而形成的,带卷产生层间滑动的原因是相邻层间的静摩擦力不足以抵消带卷的转动惯量,从而产生相对滑动。带卷板面的不平滑区域与相邻平滑区域存在明显的半径突变,滑动时在与相邻层的接触面区产生足够的压力,导致局部金属产生剪切滑移。同时提出了相应的预防措施。

In recent years,the shape quality of hot strip has been focused by more and more customer.The flattening of hot strip coil is used to improve the shape quality.However,the process of flattening brought a large number of surface quality defects.The scractch among surface defects affected on the surface quality of the strip most severely. Scratch is caused by the shear slip of local metal,resulting from the relative sliding of adjacent layers with high pres-sure.The reason of relative sliding is that the static friction between adjacent layers is not enough to counteract the rotary inertia of coil.The radius mutation between the rugged area and the adjacent smooth area causes sufficient pressure on local contact surface,which results in shear slip of local metal.Finally the corresponding preventive measures are pointed out.