输变电铁塔用耐候钢闪光焊接

Flash butt welding of weathering steel for transmission tower

文中对闪光焊接在铁塔用耐候钢上的应用展开研究,闪光焊接是通过焊接面的短路进行加热,加载顶锻变形过程界面上动态再结晶形成焊缝。焊接件经退火后,焊缝与热影响区均得到与基体相近的珠光体+铁素体组织,焊接试样与基体力学性能趋于一致。耐候钢闪光焊接无需引入其他焊料从而保证了焊缝与基体化学成分相同,并可通过热处理消除焊缝与基体之间组织差异,获得焊缝与基体力学性能的一致性。这对于无涂装输变电铁塔应用,闪光焊接一方面保证了焊接构件机械性能稳定性,另一方面避免了焊缝与基体之间因组织成分差异所带来的较大电位差,在自然环境下导致电化学腐蚀,从而满足耐候钢焊接构件免涂装服役性能要求。

Flash butt welding on the application of weathering steel for transmission tower were studied in the paper.Flash butt welding is heated by short circuit of welding section,and dynamic recrystallization on the interface forms weld during the loading and forging deformation process.After annealing of weldment,pearlite+ferrite microstructure of weld and heat affected zone was similar to that of base metal,and mechanical properties of welded samples were consistent with those of base metal.Flash butt welding of weathering steel did not need to introduce other welding materials to ensure that chemical composition of weld and base metal was the same,and the difference of microstructure between weld and base metal could be eliminated by heat treatment,and consistency of mechanical properties between weld and base metal could be obtained.For the application of non-coating metallic towers of weathering steel,on one side,flash butt welding ensured stability of mechanical properties of weldment.On the other side,it avoided large potential difference between weld and base metal due to difference in microstructure and chemical composition that led to electrochemical corrosion in the natural environment.Thus,it could meet requirements of non-coating service performance of weathering steel welded components.