基于数据挖掘的含铌X80管线钢探伤不合格原因分析与改进

Analysis on Causes Leading to Disqualification of Flaw Detection for Nb Containing X80 Pipeline Steel Based on Data Mining and Its Improvement

针对鞍钢股份有限公司鲅鱼圈钢铁分公司5500产线出现的批量含铌X80级别管线钢钢板心部存在裂纹的问题,利用扫描电子显微镜、能谱仪等检测设备对钢板裂纹缺陷进行了检测分析,发现铸坯(钢板)心部裂纹附近存在未溶铌铁颗粒。根据检测结果,聚焦炼钢环节对实际生产数据进行处理与分析,并建立基于随机森林算法的关键工艺诊断模型。分析结果表明:精炼过程中氩气搅拌流量较低、加铌铁后处理时间较短和加铌铁时温度较低是导致加入的铌铁未完全溶解的根本原因,而铸造速度过快是造成未溶的铌铁颗粒聚集在铸坯(钢板)心部的直接原因。

In allusion to the problem that cracks occurred in the cores of the X80 steel plates for pipelines containing niobium manufactured in the 5500 production line of Bayuquan Branch of Angang Steel Co.,Ltd.,these cracks were detected and analyzed by such detecting equipment as scanning electron microscope and energy spectrometer,and it was found that there were undissolved niobium iron particles near the cracks in the cores of the slabs(steel plates).According to the tested results,the actual production data were processed and analyzed by focusing on the steelmaking process,and the key process diagnosis model based on random forest algorithm was established.The analysis results showed that the low argon stirring flow rate,short post-treatment time and low temperature of adding ferroniobium during refining were the funda-mental reasons for the incomplete dissolution of added ferroniobium,while the too rapid casting speed was the direct reason for the accumulation of undissolved ferroniobium particles in the cores of slabs(steel plates).