Abstract：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.
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SHAN Qing-lin, PAN Hong-wei, LU Bo-xun, JIANG Ming-zhen, JIANG Ren-bo, SHI Xiao-wei. Control of carbon content and analysis of influencing factors in steelmaking process of ultra-low carbon BH steel[J]. China Metallurgy, 2022, 32(1): 72-76.
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2022, Vol. 32 
