X80管线钢边部裂纹成因分析与改进

管线钢属于能源用钢，涉及安全服役问题，对其质量要求也较为严格。针对管线钢在热轧轧制过程出现的边部裂纹缺陷，从宏观特征和微观形貌进行了机理分析。分析表明，边部裂纹形成原因与板坯减宽量、表面温差等存在一定对应关系。通过使用立辊减宽，减宽量小于30 mm；或使用定宽机减宽，减宽量大于150 mm进行试验。缺陷发生率明显降低，使得X80管线钢边裂缺陷从15%左右降低至4%以下，有效提升了市场占有率和客户满意度，为企业创造良好的经济效益和社会效益。

Formation analysis and improvement of edge #br# cracks in X80 pipeline steel

Pipeline steel belongs to energy steel, which involves safety service and strict quality requirements. The mechanism of edge cracks in pipeline steel during hot rolling was analyzed from macroscopic characteristics and microscopic morphology. The analysis showed that the causes of edge cracks were related to slab width reduction and surface temperature difference. By using the vertical roll to reduce the width, the reduction was less than 30 mm; or by using the sizing machine to reduce the width, the reduction was more than 150 mm. The occurrence rate of defects was obviously reduced, which reduced the edge crack defect of X80 pipeline steel from about 15% to less than 4%, effectively improved the market share and customer satisfaction, and created good economic and social benefits for enterprises.