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-Al₂O₃-MgO phase diagram with nice modifcation effect.

Key words: Pipeline Steel X70, LF, Calcium Treatment, Wire Feeding

摘要： 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-Al₂O₃-MgO系相图低熔点区,变性效果好。

关键词: X70管线钢, LF, 钙处理, 喂线