Abstract: The types and formation cause of inclusions in casting steel 38CrMoAl (/%: 0. 35 ~ 0. 42C, 0. 20 ~0. 45Si, 0. 30 - 0. 60Mn, 1. 35 〜1.65Cr, 0. 15 ~ 0. 25Mo, 0. 70 - 1. 10A1) are studied. By optimizing deoxidation technique including increasing 60 t EAF end [C] ≥ 0. 010% and maintaining high basicity slag (R≥2. 5), injecting carbon powder in bath before tapping for 2 - 3 min and controlling (FeO), decreasing adding Si-Fe amount during tapping； in LF refining process feeding aluminium wire and using aluminium shot for diffusion deoxidation, using high basicity refining slag (/% ： 50 〜60CaO, 10 - 15SiO₂, 15 - 20A1₂0₃, ≤0. 7( FeO + MnO), ≤5MgO) ； and doing best shielding casting after VD process, the A1₂O₃ types of non-metallic inclusions in steel is effectively decrease. Results show that with optimum process the continuous-continuous castin heats of steel 38CrMoAl are up to 9 heats, the rejection rate for inclusions is ≤l%.

摘要： 研究了连铸38CrMoAl钢(/%:0.35～0.42C、0.20～0.45Si、0.30～0.60Mn、1.35～1.65Cr、0.15～0.25Mo、0.70～1.10Al)夹杂物类型和形成原因。通过优化脱氧制度:提高60 t EAF终点[C]≥0.010%,保持高碱度渣(R≥2.5),出钢前2～3 min向熔池喷吹碳粉,控制(FeO),出钢过程减少Si-Fe加入量;LF喂铝线并用铝粒扩散脱氧,采用(/%)50～60CaO、10～15SiO₂、15～20Al₂O₃、≤0.7(FeO+MnO)、≤5MgO高碱度渣;做好VD后保护浇铸,有效地降低钢中Al₂O₃类型非金属夹杂物。结果表明,优化工艺后38CrMoAl钢连浇炉数达到9炉,夹杂物废品率≤1%。

关键词: EAF-LF-VD-CC流程, 38CrMoAl钢, 脱氧, 夹杂物 连续浇铸炉数