ISSN:1003-8620

CN:42-1243/TF

主管:中信泰富特钢集团股份有限公司

主办:大冶特殊钢有限公司

特殊钢 ›› 2014, Vol. 35 ›› Issue (5): 30-33.

• 工艺技术 • 上一篇    下一篇

120 t BOF-LF-RH-CC流程冶炼石油套管钢时TiN的析出和控制

方忠强 ,孙彦辉, 汪成义,蔡开科   

  1. 北京科技大学冶金与生态工程学院,北京 100083
  • 收稿日期:2014-04-26 出版日期:2014-10-01 发布日期:2022-09-01
  • 作者简介:方忠强(1987-),男,博士研究生(北京科技大学),2010年重庆大学(本科)毕业,钢液精炼和夹杂物控制。
  • 基金资助:
    国家自然科学基金资助项目(51274032)

Precipitation and Control of Titanium Nitride in Oil Casing Tube Steel Steelmaking by 120 t BOF-LF-RH-CC Flow Sheet

Fang Zhongqiang , Sun Yanhui , Wang Chengyi , Cai Kaike   

  1. School of Metallurgical and Ecological Engineering, University of Science and Technology, Beijing 100083
  • Received:2014-04-26 Published:2014-10-01 Online:2022-09-01

摘要: 石油套管用钢(/%:0.26~0.29C,0.25~0.35Si,0.40~0.50Mn,≤0.009P,≤0.004S,0.95~1.05Cr,0.09~0.11V,0.02~0.04Al,0.015~0.020Ti,≤0.0060N)的生产流程为铁水预处理-120 t BOF-吹氩-LF-喂CaSi线-RH-合金化-喂CaSi线-软吹氩-Φ220 mm圆坯连铸工艺。通过热力学分析得出钢中N含量超过50×10-6以及工业试验得出生产的圆铸坯中的N含量为67×10-6时,在铸坯中易形成2μm以上的TiN夹杂。通过控制BOF终点[N]≤30×10-6,LF终点[S]≤25×10-6,[O]≤25×10-6,[N]≤35×10-6,RH合金化后终点[N]≤35×10-6,[H]≤1.5×10-6,稳定喂CaSi线速度300~400 m/min,控制中间包[N]≤40×10-6,严格连铸保护浇铸工艺,则铸坯中的N含量≤50×10-6,钢中TiN夹杂数量显著下降,未发现大尺寸TiN夹杂物。

关键词: 120 t BOF-LF-RH-CC, 石油套管钢, TiN, 热力学计算, 氮含量

Abstract: The production flow sheet for oil casing tube steel (/% : 0.26-0.29C, 0.25-0.35Si, 0.40-0.50Mn, ≤0.009P, ≤0.004S, 0.95-1.05Cr, 0.09-0.11V, 0.02-0.04Al, 0.015-0.020Ti, ≤0.0060N) is hot metal pretreatment-120 t BOF-argon blowing-LF-CaSi wire feeding-RH-Alloying-CaSi wire feeding-soft argon blowing-Φ200 mm round bloom casting process. By commercial test as the N content in produced round casting bloom is 67 x 10-6 and by thermodynamic analysis as the N content in steel is more than 50 x 10-6, the more than 2 μm TiN inclusions easily form in casting bloom. With controlling BOF end [N] ≤ 30 X 10-6, LF end [S] ≤ 25 X 10-6 , [O] ≤ 25 X 10-6 and [N] ≤ 35 X 10-6, after alloying RH end [N] ≤ 35 x 10-6 and [H] ≤ 1.5 x 10-6, stably feeding CaSi wire speed 300-400 m/min and controlling tundish [N] ≤ 40 x 10-6 and strict casting-shielding process, the N content in casting bloom shall be ≤ 50 X 10-6, the amount of TiN inclusions in steel decreases markedly and there are not larger size TiN inclusions to be found in steel.

Key words: 120 t BOF-LF-RH-CC, Oil Casing Tube Steel, TiN, Thermodynamic Calculation, Nitrogen Content