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。
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