Abstract: With gear steel 20CrMnTi producing by 80 t LD-LF-CC process, as [Al]  s decreases from 0. 030% to 0. 015% , the production cost per ton steel shall be decreased by 25. 8 yuan. In order to un-influence the cleanliness of liquid steel, in LD tapping the slag was strictly stopped, the 2 kg/t steel-clad aluminium was added with adding high basicity slag containing ≥70% CaO and ≤5% SiO₂ to carry out slag washing, argon blowing and feeding aluminium wire to [ Al ] s 0. 015% , in LF refining, lime lump and AD powder ( Al + Al₂O₃) were added to modify slag ingredient, then feeding Ca- Si wire and soft-blowing argon for more than 10 min. Results by 5 heats test showed that with improved process, the cast billet had higher cleanliness with ( 14-15) x 10^-6T [0] , 0. 012% 〜0. 015% [S] and 0. 012% -0. 018% [P].

摘要： 80 t LD-LF-CC工艺生产齿轮钢20CrMnTi时,[Al]s从0.030%降至0.015%可使吨钢成本降低25.8元。为不影响钢水洁净度,转炉出钢严格挡渣,出钢加入2 kg/t钢芯铝,同时加入CaO≥70%、SiO₂≤5%的高碱度渣进行渣洗,吹氩喂铝线使[Al]s为0.015%。LF精炼加入石灰块和AD粉(Al+Al₂O₃)对炉渣改质,然后喂Ca-Si线,软吹氩≥10 min。5炉试验结果表明,改进工艺后铸坯具有较高的洁净度,T[O](14～15)×10-6,[S] 0.012%～0.015%,[P]0.012%～0.018%。

关键词: 酸溶铝, 齿轮钢20CrMnT, LD-LF, 洁净度