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

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

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-中110 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。

The production flowsheet for low alloy high Strength steel Q345E（/%：0.12 ~ 0.15 C,0.20 ~ 0.25 Si,1.40 ~ 1.50 Mn,≤0.010 P,≤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 ℃ and 0.5 ℃/s wind cooling process,the steel Q345 E has fine and homogeneous structure and its impact energy at-40 ℃ is 40 J.