100 t BOF-LF-RH-CC流程冶炼X70管线钢[%:0.04C、1.53Mn、0.106(Nb+V+Ti)
]
并在LF精炼时采用喂Φ13 mm 60Si-28Ca线处理。经计算和生产试验得出
喂线速度由100 m/min提高至200 m/min时
平均钙收得率由4.05%提高至14.93%
以200 m/min喂入Si-Ca线420~500 m时满足硫化物变性要求
铸坯中69%夹杂为2~10μm球形或类球形夹杂
且处在CaO-Al
2
O
3
-MgO系相图低熔点区
变性效果好。
Abstract
Pipeline steel X70 [%:0.04C
1.53Mn
0.106(Nb+V+Ti)
]
is melted by 100t BOF-LF-RH-CC flow sheet and feeding Φ13 mm 60Si-28Ca wire treatment is used during LF refining.It is obtained by calculation and commercial production test that with increasing wire feeding speed to 200 m/min from 100 m/min
the average calcium yield increases to 14.93% from 4.05%
and with feeding 420~500 m Si-Ca wire by 200 m/min
the requirement of modification on sulfide is satisfied
69% inclusions in cast billet are 2~10 μm globular and similar to globoid which locate at low-melting-point zone in CaO-Al