优化脱氧工艺提高38CrMoAl钢连浇成功率

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％.

Increasing Continuous-Continuous Casting Success Rate of Steel 38CrMoAI by Optimizing Deoxidation Process

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 endC]≥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,10～15SiO₂,15～20Al₂O₃,≤0.7（FeO + MnO）,≤5MgO）;and doing best shielding casting after VD process,the Al₂O₃ types 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≤1%.