帘线钢冶炼氮含量控制研究与实践

Study on Control of Content of Nitrogen in Cord Melten Steel during Smelting and Its Practice

针对帘线钢拉拔断裂缺陷,研究了相关工艺参数对钢中氮含量的影响,并采取了相应的优化措施,转炉冶炼采用低氮增碳剂,减少倒炉次数,吹炼全程均采取底吹氩模式;LF发泡埋弧、快速成渣及形成微正压气氛;强化连铸保护浇注工艺,抑制钢水二次氧化。上述措施实施后,帘线钢氮含量得到了较好控制,由0.004 010%降至0.002 726%,且基本稳定控制≤0.003 0%。提高了帘线钢实物质量,满足客户拉拔至0.17 mm的要求。

With regard to the fracture defect occurred in drawing the cord steel,the effect of relevant process parameters on content of nitrogen in the steel was studied.And then corresponding optimization measures such as using low nitrogen carburizing agent during smelting by converter,reducing the number of times for tapping from converter,blowing argon from bottom of converter during the whole smelting process,using foaming slag in submerged arc operation,rapid forming slag and forming micro-positive pressure atmosphere during LF refining,strengthening protective casting process during continuous casting for inhibiting secondary oxidation of cord molten steel were taken.After these measures were put into operation,the content of nitrogen in cord molten steel was well controlled and the content was reduced to 0.002726%from 0.004010%,and stably controlled to be equal or less than 0.0030%,which improved the quality of the cord steel and met the requirement asked by drawing the steel diameter to 0.17 mm.