不锈钢AOD精炼工艺的改进

Improvement of AOD Refining Process for Stainless Steel

通过生产试验改进了太钢 4 0tAOD精炼工艺参数。提高氧化 1期吹炼气体中氧气的比例、炉渣碱度和炉渣中MgO含量 ,降低精炼温度。改进后精炼工艺参数为氧化 1期吹炼气体中氧∶氮 =(4～ 5 )∶1,氧化2期氧∶氩 =1∶(1～ 2 ) ,精炼温度≤ 1710℃ ,炉渣CaO SiO2 ≥ 1.4 ,炉渣中MgO含量≥ 8%。使用改进的AOD精炼工艺冶炼 18 8不锈钢时 ,[S]从原来的 0 .0 0 8%降至 0 .0 0 5 % ,渣中Cr2 O3平均含量由 6 .78%降至 0 .73% ,镁白云石炉衬平均寿命由 5 6次提高到 10

The refining process parameters of a 40 t AOD unit at Taiyuan Steel have been improved by production test such as to increase the ratio of oxygen in blowing gas in first oxidation period, the basicity of slag and MgO content in slag, and decrease the refining temperature. The improved refining process parameters were oxygen∶nitrogen = (4～5)∶1 in blowing gas in first oxidation period, oxygen∶argon = 1∶(1～2) in second oxidation period, refining temperature ≤ 1 710 ℃, CaO/SiO 2≥1.4 and MgO content ≥8% in slag. With using improved AOD refining process to melt 18-8 stainless steel, the [S] decreased to 0.005% from original 0.008%, Cr 2O 3 average content in slag decreased to 0.73% from 6.78%, average life of furnace lining of magnesium dolomite increased to 100 heats from 56 heats.