控轧控冷工艺参数对风电法兰用钢Q345E低温冲击韧性的影响

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。

Effect of Controlling Rolling and Cooling Parameters on Low Temperature Impact Toughness of Q345E Steel for Wind Power Flange

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.