关键词: 顶底复吹转炉, LF+RH-TB 精炼, 轴坯钢LZ50, ,  , 冶金质量

Abstract: The 230mm×230 mm×1350 mm LZ50 steel billet for vehicle axle is produced by quality hot metal pretreatmnent - 120 t converter melting and SiAlBaSrCa combined deoxidiing- ladle refiring with Si-Ca powder injection + RH- TB vacuum degassing- 5 t ingot casting - rolling process. The production results showed that due to controlling C content be- tween0.47%～0.50%,Si0.20%～0.35%,Mn0.71%～0.85%,both P,S in steel ≤0.02%,average[H]=1.77 ×10-⁶,average  [O]=12.22×10-⁶,the  LZ50  steel  billet  had  excellent  macro  structure  and  constant  mechanical  properties, and the quality of products was up to the requirement of TB/T2945 standard.

Key words: Top and Bottom Combined Blown Converter, LF + RH-TB Refining, LZ50 Steel Billet for Vehicle Axle, Metallurgical Quality