铸坯到轧材的表面缺陷演变行为研究

Evolution Behavior of Surface Defects from Casting Slab to Rolled Metal

基于铸坯表面缺陷传承到轧材的精确定位方法,开展铸坯-轧材缺陷间的对应关系研究,以提高判断缺陷产生原因以及工序改进的及时、精准性,并系统研究高线铸坯皮下气泡缺陷在轧制过程中的演变行为,对其缺陷形态进行了检测分析。研究表明:所设计的铸坯表面缺陷到轧材的定位方法能精确地在轧材表面找到缺陷所在的位置;铸坯皮下气泡对应的轧材表面裂纹长度较短,且裂纹两端收敛,无明显过渡段,裂纹内部存在氧化物,裂纹两侧组织无异常流变,存在明显脱碳,这为企业改善铸坯表面质量提供了科学依据。

Based on the accurate location of surface defects from casting slab to rolled metal,the corresponding relationship of defects between casting slab and rolled metal were researched in order to find out the causes of defects and improve process in time and more precisely. And the evolution behavior of subsurface bubbles of casting slabs during rolling process was systematically studied,and the patterns of the defects were analyzed. The results show that the defect location method for the surface defects from casting slabs to rolled metal can accurately locate the surface defects of rolled metal. The surface cracks of rolled metal corresponding to subsurface bubbles of casting slabs are shorter and have the following features. Both tips flocking together,no obvious transition,oxide in the cracks,no abnormal rheology of microstructure near the cracks,and obvious decarburization,which can provide scientific basis for improving the surface quality of casting slabs.