碳素钢铸坯表面横裂纹原因分析与控制

ANALYSIS AND CONTROL OF TRANSVERSE CRACKS ON THE SURFACE OF CARBON STEEL SLABS

某炼轧厂碳素钢因生产工艺控制及过程参数使用不当,造成轧后表面翘皮、舌头状及指甲状结疤缺陷突出。通过去除铸坯表面氧化铁皮、边部酸蚀等方式检查轧后缺陷批次表面质量,发现铸坯表面横裂纹、角部横裂纹是造成该缺陷的主要原因。通过对该系列钢种工艺C含量、生产过程结晶器振动参数及扇形段二次冷却水强度进行优化,达到减少铸坯表面横裂纹及角部裂纹的目的,从而降低铸坯轧后结疤率。

Due to improper production process control and process parameter use,carbon steel in a refinery and rolling mill has prominent defects such as surface warping,tongue-like and finger-like scarring after rolling.By removing the iron oxide scale on the surface of the casting slab and acid corrosion on the edges,the surface quality of the defective batch after rolling was inspected.It was found that the transverse cracks on the surface of the cast blank and the transverse cracks at the corners were the main causes of the defects.By optimizing the process C content of this series of steel grades,the vibration parameters of the crystallizer during production,and the intensity of secondary cooling water in the sector,the purpose of reducing transverse cracks on the surface of the cast blank and corner cracks was achieved,thereby reducing the scar rate after rolling.