超低碳BH钢炼钢过程对碳含量的控制及影响因素分析

基于炼钢过程批量取样的分析结果,系统研究了 RH控碳能力、控氮能力、合金残余元素、耐材中碳含量、中间包增碳、元素的检测分析能力对BH钢碳含量的影响规律.RH脱碳15 min可将碳质量分数稳定控制在0.001 0％～0.001 5％是BH钢碳含量稳定控制和精炼周期控制的重要基础.RH结束N元素质量分数控制在0.001 2...

Control of carbon content and analysis of influencing factors in steelmaking process of ultra-low carbon BH steel

Based on the detection analysis results of samples taken from the steelmaking process of BH steel, the influences on carbon content in steel were studied, such as RH de-carbon and de-nitrogen control ability, residual elements in ferroalloy, carbon content in refractory, carbon pickup in tundish and detection ability at testing room. It was necessary to control carbon mass fraction between 0.001 0%-0.001 5% in 15 min during RH decarbon process for controlling the refining cycle. And it was important to control nitrogen mass fraction between 0.001 2%-0.002 4% at the end of RH treatment, in order to simplify the solute carbon control in steel for Nb-Ti bearing steel grade. The restrictive factor of refining to carbon pickup in tundish was the carbon content in steel ladle and refractory, it was also necessary to control carbon pickup under 0.000 1% in ladle and 0.000 3% in tundish in order to control the total C pick-up less than 0.000 4% during the continuous casting process. For the requirement of element detection, the analysis deviation should be less than 0.000 3% for the element of Nb, Ti and B, and less than 0.000 2% for the element of C in spectral analysis and carbon and sulfur analysis. Then the steelmaking process for BH steel grade was proposed and optimized. The qualified rate of solid solution carbon internal control of BH steel increased from 65% to 93% and the above control measures could be used as reference for BH steel production in other enterprises.