≤0.025P)采用100t DC EAF-LF-VD-280 mm×320 mm坯连铸工艺流程生产。通过控制出钢钢包温度≥1000℃
出钢时加入200 kg硅铁
钢包底吹氩搅拌;LF采用专用精炼渣系(/%:45~55CaO
15~25Al
2
O
3
15~25SiO
2
)
喂硫线
≥15 min VD处理后控制钢水过热度20~35℃
二冷比水量0.18 L/kg
拉速0.45~0.55 m/min等工艺措施
可稳定控制钢水硫含量和钢水的可浇性
铸坯中心疏松和缩孔级别≤1.5;[O
]
为14×10
-6
~15×10
-6
[H
]
1.3×10
-6
~1.5×10
-6
非金属夹杂物满足质量要求。
Abstract
Medium carbon sulphur free-cutting steel SAE1144 (/%: 0.42-0.47C
0.15-0.30Si
1.45-1.65Mn
0.24-0.30S
≤0.025P) is produced by 100t DC EAF-LF-VD-280 mm x320 mm bloom casting process. With process measures including controlling tapping ladle temperature m 1 000adding 200 kg ferrosilicon during tapping
ladle bottom argon blowing stirring
using LF special refining slag series (/% : 45-55CaO
15-25Al
2
O
3
15-25SiO
2
)
feeding sulphur wire
controlling liquid overheating extent 20-35 °C after VD treatment for ≥15 min
controlling secondary cooling water rate 0. 18 L/kg and casting rate 0.45-0.55 m/min
the sulphur content in liquid and castability of liquid are stably controlled
and the rating of
central porosity and shrinkage cavity is ≤1.5
[O
]
is 14 x 10
-6
-15 x
10
-6
and [H
]
is 1.3x
10
-6
1.5 x
10
-6
to meet the requirement for nonmetallic inclusions and quality.