Abstract: The production flowsheet for low alloy high Strength steel Q345E (/% ： 0. 12 ~ 0. 15C, 0. 20 ~ 0. 25Si, 1. 40 ~ 1. 50Mn， ≤0. 010P, ≤0. 005S) is 80 t top and bottom combined blown converter- LF- RH- Φ450 mm bloom CC-Φ110 mm bar continuous rolling process. The effect of reduction ratio ( 10. 33 ~ 20. 25) , beginning rolling temperature (1 120 ~ 1 080 ℃ ) and cooling mode (0. 2 ℃/s air cooling and 0. 5 ℃/s wind cooling) on V-notch impact energy of steel at -40 ℃ has been commercial-tested. Results show that with increasing reduction ratio, decreasing beginning rolling temperature and increasing cooling speed the impact energy of steel at -40 ℃ obviously increases; and with using reduction ratio 16. 74, beginning rolling at 1 100 °C and 0. 5 °C/s wind cooling process, the steel Q345E has fine and homogeneous structure and its impact energy at -40 ℃ is 40 J.

摘要： 低合金高强度钢Q345E（/%:0.12~0.15C,0.20~0.25Si,1.40~1.50Mn,≤0.010P,≤0.005S）的生产流程为80 t顶底复吹转炉-LF-RH-Φ450 mm铸坯CC-Φ110 mm棒材连轧工艺。工艺试验了压缩比（10.33~20.25）、开轧温度（1120~1 080℃）和冷却方式（0.2℃/s空冷和0.5℃/s风冷）对该钢-40℃,V-型缺口冲击韧性的影响。结果表明,随压缩比增加,开轧温度降低,冷却速度增加,该钢-40℃冲击功显著增加,采用压缩比16.74,开轧温度1100℃,0.5℃/s风冷工艺,Q345E钢组织细小、均匀,-40℃冲击功为40 J。

关键词: 风电法兰用钢Q345E, 控冷控轧工艺, 组织, 低温冲击功