Abstract: In response to the surface defects such as concavities， deep vibration marks， cracks， and slag pits on the surface of continuous casting billets during the smelting of N2M2T high-strength welding wire steel in a certain steel plant，combined with theoretical analysis and actual production conditions on site， an analysis was proposed to analyze the surface defects of N2M2T high-strength welding wire steel continuous casting billets from four aspects： the physical and chemical properties of protective slag， mold vibration parameter mode， primary cooling water distribution， and N content in the steel. The analysis results indicate that the surface defects generated by continuous casting billets are mainly related to the physicochemical indicators of the protective slag， mold vibration parameters， and N content in the steel， but not to the primary cooling water distribution. Production practice shows that by increasing the alkalinity of the protective slag from 0. 6 to 1. 19， the C content is reduced from 13. 51% to 8. 21%， and the viscosity is reduced from 0.666 Pa. s to 0.156 Pa. s； The deviation rate of mold vibration parameters has been increased from 0.15 to 0.20， and the vibration frequency formula has been adjusted from 60+50 V to 90+60 V； Control the N content in steel to ＜50 × 10^-6， continuous casting process △ N ＜ 7 × 10^-6； The surface defects of N2M2T high-strength welding wire steel continuous casting billet have been significantly improved， and the qualification rate of the billet has increased from 85% to over 95%， providing assurance for stable rolling of subsequent steel rolling

Key words: High Strength Welding Wire Steel, Casting Vibration Marks, Protective Slag, Corner Cracks, Continuous Casting Billet

摘要： 针对某钢厂在冶炼N2M2T高强焊丝钢时，连铸坯表面出现的凹陷、角部深振痕裂纹及渣坑等表面缺陷，结合理论分析及现场实际生产情况，从保护渣理化性能、结晶器振动参数、一冷配水及钢中N含量等对铸坯表面产生的缺陷进行分析。结果表明，连铸坯产生的表面缺陷主要与保护渣理化指标、结晶器振动参数、钢中 N含量有关，而与一冷配水关系不大。生产实践表明，通过将保护渣碱度从 0. 6提高到 1. 19，w［C］从 13. 51%降低到 8. 21%，粘度从0. 666 Pa. s降低到0. 156 Pa. s，结晶器振动参数偏斜率由0. 15提高至0. 20，振频公式由60+50 V调整为90+60 V，钢中 N 含量控制在＜50×10^-6，连铸工序△N＜7×10^-6等措施，N2M2T 高强焊丝钢连铸坯的表面缺陷得到明显改善，铸坯合格率从85%提高到95%以上，为后续轧钢的稳定轧制提供了保证。

关键词: 高强焊丝钢, 铸坯振痕, 保护渣, 角部裂纹, 连铸坯