高级别管线钢中碳磷硫控制工艺研究与应用

RESEARCH AND APPLICATION OF CARBON,PHOSPHORUS AND SULFUR CONTROL TECHNOLOGY IN HIGH-LEVEL PIPELINE STEEL

分析了高级别管线钢中碳磷硫对钢材质量的影响,通过对钢液中[C]、[P]和[Fe]选择性氧化的热力学理论分析,计算出转炉终点温度在1 640℃时,当碳低于0.06%时,继续供氧,氧气将优先与[P]反应生成(P2O5),能够实现熔池的深脱磷;但当碳低于0.04%时,继续供氧,氧气将直接与[Fe]反应为主,造成钢水过氧化,甚至发生回磷现象。通过优化拉碳工艺、优化铁水预处理脱硫工艺、控制转炉回硫、LF渣系等,实现了高级别管线钢成品w[C]≤0.05%,w[P]≤0.012%,w[S]≤0.001 5%的稳定生产工艺。

Abstract： The influence of carbon, phosphorus and sulfur on the steel quality of high - level pipeline steel was analyzed. It is calculated that deep dephosphorization of molten pool could be achieved because oxygen would give priority to PI to react to produce （P205） if oxygen feeding was continued when the converter terminal temperature was 1 640 ℃ meanwhile the content of carbon was less than 0. 06% , by the thermodynamic analysis of the selective oxidation of [ C ] , [ P] and [ Fe] in the molten steel. However, oxygen would react directly with [ Fe] mainly, resulting in molten steel overoxidation, even the phenomenon of rephosphorization if keeping feeding oxygen when content of carbon is less than 0. 04%. The stable production procees for high- level pipeline steel products has been achieved with w [ C] 〈0.05% , [ P] 〈0.012%, w [ S ] 〈 0. 001 5% by optimizing the catch carbon process and desulfurization pretreatment process of hot metal, controlling converter resulfurization and LF slag, etc.