Abstract: The steelmaking process flow sheet of ferrite heat resisting steel P91 for boiler (% ; 0. 08 ~0. 12C, 8. 0 ~ 9. 5Cr, 0. 85 ~ 1. 05Mo, 0. 18 ~0. 25V, 0. 06 〜0. 10Nb, 0. 030 ~0. 070N) is 20 t EBT EAF + 10 t induction furnace mixing melting- LF-VOD (nitrogen blowing) - 3 t ingot mold casting. With bottom blowing nitrogen gas stirring in low vacuum (~ 26 000 Pa) to make sufficient and quick reaction between deoxidizer, slag-making materials and liquid, the [ N ] increases from (80 ~ 90) x 10^-6 to ( 120 〜140) x 10^-6 , then by nitrogen bottom-blowing with (9 ~ 15) x 10^-6/min increasing rate of N content in liquid, the [ N] shall increases to 620 x 10^-6, and the nitrogen content in steel products is about 500 x 10^-6 to meet the requirement of standard.

摘要： 锅炉用铁素体耐热钢P91(%:0.08～0.12C、8.0～9.5Cr、0.85～1.05Mo、0.18～0.25V、0.06～0.10Nb、0.030～0.070N)的冶炼工艺流程为20 t EBT EAF+10 t感应炉混炼-LF-VOD(吹氮)-3 t锭模铸。通过低真空(～26 000 Pa)底吹N气搅拌使脱氧剂、造渣材料充分快速与钢液反应,使[N]从(80～90)×10^-6增至(120～140)×10^-6,然后底吹氮以(9～15)×10^-6/min的增氮速率将[N]增至620×10^-6,钢材中的N含量约为500×10^-6,达到标准要求。

关键词: 高氮钢P91 , VOD, 底吹氮精炼