输电线路钢管塔用Q460C直缝焊管组织和性能试验研究

对Q460C高频直缝焊管的组织和力学性能及其冷裂纹敏感性进行了试验研究。研究结果表明，Q460C焊管虽然满足输电铁塔的性能要求，但若批量生产需对钢材的化学成分、非金属夹杂物的类别进行控制；由于焊缝的冲击性能与管体相比降低30%～50％，应优化直缝焊管的生产工艺，使之更加适应钢管加工工艺的变化；Q460C焊管有一定的焊接冷裂纹敏感性，但其焊接热影响区淬硬倾向不明显。在0℃及以下温度焊接Q460C直缝焊管时，应进行焊前预热，预热最低温度为100℃。

Research on Structure and Property of Q460C Longitudinal Welded Pipe Used for Steel Pipe Tower of Transmission Electricity Line

The structure,mechanical property and cold cracking sensitivity of Q460C high frequency longitudinal welded pipe were studied respectively.The results indicated that although Q460C welded pipe can meet requirements of transmission electricity tower,chemical composition of steel plate and the kind of non-metallic inclusion should be controlled in mass production.Because the weld impact property is 30%~50% lower than that of pipe body,so the production process of longitudinal welded pipe should be optimized to adapt to the change of steel pipe processing technology.Q460C steel pipe has certain cold cracking sensitivity,but its quenching trend of HAZ is not obvious.It should be preheated before welding at 0 ℃ and below,and the lowest preheating temperature is 100 ℃.