包钢X65管线钢Φ300 mm圆铸坯的试制

Pilot Production ofΦ300 mm Round Casting Bloom of X65 Pipeline Steel at Baogang

包钢钢联股份有限公司炼钢厂采用120 t顶底复吹转炉-100 t LF(VD)-5流Φ300 mm铸坯连铸工艺流程试生产X65管线钢13MnNbTi(%:0.10～0.16C、1.20～1.40Mn、0.03～0.05Nb、0.01～0.02Ti、0.025～0.05Al)。生产实践表明,通过铁水脱硫([S]≤0.005%),转炉挡渣出钢,精炼渣碱度≥3.0,VD处理≥13 min,可以使[S]≤0.005%、[P]≤0.015%、[H]≤1.5×10^(-6)。通过全程保护浇铸和结晶器电磁搅拌工艺,钢中氧含量(13～21)×10^(-6),平均氧含量16.44×10^(-6),铸坯表面质量良好,低倍组织0～1级。

The X65 pipeline steel 13MnNbTi （%：0.10～0.16C,1.20-1.40Mn,0.03-0.05Nb,0.01-0.02Ti,0.025～0.05Al） is pilot-produced by 120 t top and bottom combined blown converter-100 t LF （VD）-5 strands alp300 mm round bloom casting flow sheet at steelmaking plant, Baotou Steel Union Co Ltd. Production practice shows that it is available by desulphurization of hot metal （ [ S ] ≤ 0. 005 % ）, using slag stopper during converter tapping, basicity of refining slag ≥3.0, VD treatment ≥ 13 min, to get [ S] ≤0. 005%, [ P] ≤0. 015% and [ H] ≤ 1.5 ×10^-6. With shielding casting in whole process and mold electromagnetic stirring, the oxygen content in steel is （ 13 - 21 ）×10^-6, average oxygen content is 16. 44×10^-6, the surface quality of bloom is fine and the rating of maerostructure is 0 - 1.