Cf53钢冶炼浇铸工艺研究

Study on smelting and casting technologies of Cf53

采用60tBOF→60tLF→200mm×200mm方坯CC工艺生产Cf53钢,冶炼与连铸工艺要点包括:控制转炉终点成分、温度和下渣量;控制LF炉渣碱度R在4.0～5.5之间,渣中w(Al2O3)15%～20%、w(MnO+FeO)<1.5%;优化喂线工艺,保证白渣保持时间不小于15min;采用全保护浇铸和M+F电磁搅拌等。检验结果表明,采用该工艺生产的Cf53钢中,w(O)平均为6.6×10-6,w(N)平均为73.55×10-6,铸坯缩孔和中心疏松均在1.0级以下,明显改善了铸坯的宏观组织形貌。

Cf53 steel is produced at Jiyuan Steel by using 60tBOF-60t LF 200 mm× 200 mm CC processes. The key smelting and casting technologies are as follows, controlling of BOF endpoint compositions, temperature and the quantity of slag controlling of slag basicity R for LF in a range of 4-5.5, Al2O3 content in slag 15 %-20 %, w（MnO＋ FeO） 〈1.5 %, optimizing of wire feeding process to ensure white slag retaining time not less than 15 minutes adopting of whole protective casting and M-kF electromagnetic stirring. Testing results showed that Cf53 steel produced by the technologies has good quality and properties, average [O] 6.6 ×10-6, average [N] 73.55 ×10-6, casting shrinkage and porosity are in Rank 1, which means the macro morphology of casting billet are significantly improved.