X70管线钢LF控氮工艺分析

Analysis on the Nitrogen Control of Pipeline Steel X70 in LF Process

对X70管线钢生产工艺及LF过程控氮因素进行了综合分析。结果表明,LF工况条件下造白渣脱硫阶段的"钢液裸露"是造成钢液增氮最为主要的原因。在此基础上提出了从BOF出钢到LF处理结束等6项X70管线钢LF控氮工艺要点。根据LF生产实践不断完善与优化其各环节的技术参数,为生产更低含氮量要求的高级别钢种奠定理论与工艺基础。

The production process for X70 pipeline steel and the control nitrogen factors in LF process were comprehensively analyzed. The results show that the nitrogen pick-up in liquid steel is mainly attributed to the liquid steel exposed to atmosphere at the desulfurization stage under the white slag conditions in LF processs. Accordingly, six key technologies of nitrogen control for pipeline steel X70 from BOF tap to LF end-point were proposed. According to LF practice, constant perfecting and optimizing its technical parameters can lay a theoretical and technological foundation for producing high grade steel containing lower nitrogen.