In response to the surface defects such as concavities,deep vibration marks,cracks,and slag pits on the sur-face 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 sur-face 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 fre-quency formula has been adjusted from 60+50 V to 90+60 V;Control the N content in steel to＜50 ×10-6,continuous cast-ing 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 assur-ance for stable rolling of subsequent steel rolling.
维普
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