During refining process of steel 1Cr13 etc 400 series stainless steels in a 60 t AOD unit with direct charging hot metal

due to adding large amount of materials including ferrochromium alloy

slag-forming addition and return scrap

the required heat accounts for 15% 〜40% of the total heat of bath

that seriously restricts smooth refining and improving liquid quality. The effect of 60 t AOD lance level (1.5 ~ 3. 5 m) on CO post-combustion ratio

the effect of silicon content (1 % ~6. 5%) in ferrochrome on lime consumption and comprehensive supply of heat and the effect o£ baking time (0. 5 ~ 4. 5 h) on alloy temperature are studied by commercial production practice. Results show that with controlling 60 t AOD oxygen lance level at 3 m the CO post-combustion ratio increases to 20% ； with 4% silicon content in ferrochrome the comprehensive work efficiency is maximum ； and the time of alloy baking for 2 ~ 3 h is optimum.