Abstract: The 0. 17~0.23C-≤0. 15Mo steel 20G for high pressure boiler is melted by a 92 t UHP EBT EAF-LF process at Chengdu Iron and Steel,Pan Steel Group. The operation practice showed that 35% pig iron in charge for arc furnace,adding 3~10 mm carbon particle and stengthening supply oxygen to form 500~750 mm foaming slag were available to remove partial nitrogen in molten steel,as a consequence the average nitrogen in steel came to 45×10-⁶ at arc furnace tapping. During LF refining, the operation of large amount slag embedding arc, weak argon stiring and cutting-down heating time was adopted to control the increment of nitrogen in steel no more than 10×10-⁶ in refining period.The nitrogen content in steel after refining in LF was(60~66)×10-⁶,that was efficiently to prevent aged brittleness of steel products.

Key words: Electric Arc Furnace, Ladle Furnace, Control of Nitrogen Content

摘要： 攀成钢公司采用92 t EBT(偏心底)UHP EAF-LF(钢包炉)工艺冶炼成分(%)为0.17~0.23C-≤0.15Mo的高压锅炉钢20G。操作实践表明,在EAF(电弧炉)炉料中配加35%的生铁,并通过添加3~10 mm的碳粒和强化供氧,形成500~750 mm的泡沫渣,以利去除钢液中的部分氮,使EAF出钢时钢中氮含量平均达到45×10^-6。LF精炼时采用大渣量埋弧操作,氩气弱搅拌和缩短加热时间,以便控制精炼时钢液增氮量不超过10×10^-6,并使LF精炼后钢中氮含量达(60~66)×10^-6,有效地防止钢材产生时效脆性。

关键词: 电弧炉, 钢包炉, 氮含量控制