Abstract: Flow sheet for production of carbon structure steel and steel for ship plate at Xingcheng Special Steel is 150 t BOF-LF-RH-200 ~250 mm slab CC process. Effect of slag-making submerged arc operation, power supply schedule, LF heating time, ladle bottom argon blowing etc process factors on nitrogen pick-up in molten steel during refining process has been statistic-analyzed. With controlling of opening of valve in dust-exhausting absorbing wind tube to maintain slight positive pressure operation in LF, in earlier period of refining using higher power supply and in latter period of refining using lower power supply, blowing argon rate in earlier, middle and latter refining period being respectively 200, 400 -500 and 200 ~ 300 L/min, and controlling LF slag amount ratio 1.2% etc measures, the increment of [N] in LF refining process is ≤ 5 x 10 ^-6, and without via RH vacuum treatment, it is available to control the nitrogen content in slab ≤ 50 x 10^-6

摘要： 兴澄特钢生产碳素结构钢和船板用钢的生产流程为150 t BOF-LF-RH-200~250 mm板CC工艺。统计分析了精炼过程造渣埋弧操作、送电制度、LF加热时间、钢包底吹氩等工艺因素对钢水增氮的影响。通过控制除尘吸风管道阀门开启度,保持LF内微正压操作,精炼前采用较高供电功率,后期用低供电功率,精炼前、中、后期分别采用氩气流量200,400~500,200~300 L/min,以及控制LF渣量1.2%等措施可使LF精炼过程的增氮量≤5×10^-6,不经过RH真空处理,可控制板坯氮含量≤50×10^-6。

关键词: 低碳钢, LF精炼, 控制钢水增氮, 工艺实践