SPA-H耐候钢边部裂纹缺陷的原因分析及改进措施

Cause Analysis and Improvement Measures of Edge Crack Defect of SPA-H Weathering Steel

针对SPA—H耐候钢边部裂纹缺陷的宏观特征和微观特征进行了分析。结果表明，带钢边部裂纹缺陷表面主要是由氧化铁皮构成，截面带有一定的延伸裂纹，且裂纹附近有一定的氧化质点。通过排查轧制温度、加热制度和板坯质量等因素，最终确定SPA-H耐候钢边部裂纹缺陷是由板坯裂纹遗传所致。通过采取板坯停止热送、定期标定结晶器锥度、定期检查板坯断面情况以及提高出钢温度等措施后，有效控制了SPA—H耐候钢边部裂纹缺陷。

The macroscopic and microscopic characteristics of the edge crack defects of SPA-H weathering steel were analyzed. The results showed that the surface of the edge crack was mainly composed of the scale, with a certain extension crack on the section, and there were some oxide particles near the crack. By checking factors such as the rolling temperature, the heating process and the slab quality, it was finally determined that the edge crack of SPA-H weathering steel was caused by the slab crack. The edge crack defects of SPA-H weathering steel were effectively controlled by taking measures such as stopping hot delivery of the slab, regularly calibrating the mould taper, regularly checking the slab section and increasing the reheating temperature.