Abstract: The production flowsheet for developed casting round bloom of steel P11 (/% : 0. 08 ~ 0. 14C, 0. 65 ~ 0. 85Si, 0. 40 ~0. 60Mn, ≤0. 010P, ≤0. 010S, 1. 10 ~ 1. 30Cr, 0. 46 -0. 60Mo, ≤0. 015Alt) is KR metal pretreatment- 70 t top and bottom combined blown converter- LF- VD- round bloom casting process. With using the measures including controlling the elements content /% : 0. 09 ~ 0. 11C, 1.15~1. 20Cr, 0. 07 ~ 0. 08P, 0. 002 ~ 0. 005S and 0. 008 ~ 0. 015Als, controlling tundish liquid temperature (1538 ±5) ℃ , casting speed 0. 70 ~ 1. 05 m/min, secondary cooling water ratio 0. 35 ~0. 40 L/kg, strengthening temperature ≥900 °C and temperature of slow cooling pit furnace ≥500 ℃，the examination results show that the surface quality of casting bloom is qualified with rating of shrinkage cavity ≤0. 5 and rating of central porosity ≤1. 0, the P content in steel is 0. 007% ~ 0. 008% and the S content in steel is 0. 002% ~ 0. 005% , so the steel has better flowing accelerating corrosion (FAC) resistance at service temperature.

摘要： 开发的P11钢（/%:0.08~0.14C,0.65~0.85Si,0.40~0.60Mn,≤0.010P,≤0.010S,1.10~1.30Cr,0.46~0.60Mo,≤0.015Alt）连铸圆坯的生产流程为KR铁水预处理-70 t顶底复吹转炉-LF-VD-圆坯连铸工艺。通过控制/%:0.09~0.11C,1.15~1.20Cr,0.07~0.08P,0.002~0.005S,0.008~0.015Als,中间包钢液温度（1538±5）℃,连铸拉速0.70~1.05 m/min,二次冷却比水量0.35~0.40 L/kg,矫直温度≥900℃,缓冷坑温度≥500℃等工艺措施,检验结果表明,铸坯表面质量合格,缩孔≤0.5级,中心疏松≤1.0级,钢P含量为0.007%~0.008%,S含量0.002%~0.005%,该钢在工作温度下有较好的耐流动加速腐蚀性（FAC）。