Nb-Ti微合金化含铬J55石油套管用钢的生产实践

8~10 mm J55石油套管用钢板的生产流程为铁水预处理-120 t顶底复吹转炉-LF精炼-87 mm薄板坯连铸-连轧工艺。通过在原有0.015%~0.025%Nb微合金化钢的基础上优化J55石油套管钢的成分(/%:0.16~0.18C,0.5~0.7Mn,≤0.20Si,≤0.025P,≤0.010S,0.03~0.04Cr, 0.01~0.03Ti,0.005~0.010Nb),转炉出钢加200~400 kg铝镁钙预脱氧、精炼过程喂铝线深脱氧,TO]≤20×10^-6时钙处理,板柸加热温度1 100~1 130℃,终轧855~860℃,轧后快速冷却,(610±10)℃卷取等工艺措施,成品钢板屈服强度437~465 MPa,抗拉强度549~575 MPa,伸长率30%~36%,-20℃冲击功60~96 J,180°冷弯合格,各项性能稳定。

Production Practice of Nb-Ti Microalloying and Containing Cr Steel J55 for Oil Casing Tube

The production flowsheet of 8?10 mm plate of steel J55 for oil casing tube is hot metal pretreatment-120 t top and bottom combined blowing converter-LF refining-87 mm thin slab casting-continuous rolling process. With the process measures including based on original 0.015% ~0.025% Nb microalloying steel optimizing the composition of J55 steel for oil casing tube (/%:0.16 ~0.18C, 0.5-0.7Mn, ≤0.20Si, ≤0.025P, ≤ 0.010S, 0.03 ~0.04Cr, 0.01 ~ 0.03Ti, 0.005 ~0.010Nb) pre-oxidizing by adding 200 ~ 400 kg aluminium magnesium calcium alloy at converter tapping, deep de-oxidizing by feeding aluminium wire and calcium treating at TO]≤20 x 10^-6 during refining process, slab heating at 1 100 - 1 130 ℃ , finishing rolling at 855 ~ 860 °C and quick cooling after rolling, and coiling at (610 ± 10) ℃， the properties of finished steel plate are yield strength 437 ~465 MPa, tensile strength 549 ?575 MPa, elongation 30% ? 36%, impact energy at -20 ℃ 60 ~ 96 J, 180℃ cold-bending test qualified, and each properties of products are steady.