Abstract: Two kinds of metallurgical process for melting a <0.005%C-≤0.005% N ultra-low carbon and ultra-low nitrogen steel by a 90 t top and bottom combined blown converter a Wuhan Iron and Steel: single slag process KR desulphuration -LD - RH-KTB - CC and two-step steelmaking process KR desulphuration - LD desiliconisation and dephosphorization-LD combined blown decarbonation - RH-KTB- CC have been analyzed. The practice results showed that during steelmaking with single slag process the average C content in liquid steel in tundish was 25.5×10^-6 and the average N content was 18.5×10^-6 and with two-step process the average C content in liquid steel in tundish was 16×10^-6, the average N content was 19×10^-6,and the end [P] with two-step process(60×10^-6)was lower that with single slag process(110×10^-6).

摘要： 分析了武钢90t顶底复吹转炉冶炼<0.005%C,≤0.005%N超低碳、氮钢的两种冶炼工艺技术,即常规工艺:KR脱S→LD→RHKTB→CC和双联工艺:KR脱S→LD脱Si、P→LD复吹脱碳→RHKTB→CC。实践表明,常规工艺冶炼时中间包钢水平均C含量为25.5×10^-6、平均N含量为18.5×10^-6;双联工艺冶炼时,中间包钢水平均C含量为16×10^-6、平均N含量为19×10^-6,双联工艺吹炼终点[P](60×10^-6)比常规工艺(110×10^-6)低。

关键词: 超低碳, 超低氮, 转炉, , RH-KTB 精炼, 冶炼