冬季严寒环境高性能耐候钢桥焊接施工技术

Construction Technology for Welding High-Performance Weathering Steel Bridges in Cold Winter Environments

针对黑龙江大桥桥位冬季-48℃严寒环境的焊接施工,结合黑龙江大桥横纵梁的结构特点,采用可移动式加热保温棚,棚内使用工业取暖气进行加热,配合平铺式感应加热带进行焊前预热,使焊接环境和焊接预热满足工艺要求,焊后采取后热措施,采用特定的焊接工艺并控制焊接热输入,保证焊接质量,得到高性能耐候钢焊接接头-40℃冲击功KV2≥47 J、-60℃冲击功KU2≥47 J,耐大气腐蚀性指数I≥6.0,满足了大桥钢梁制造冬季焊接需要和免涂装使用要求。这种方法对于我国其他严寒地区钢结构的冬季焊接施工同样适用,如川藏线铁路位于高原高寒地区,环境复杂,气候恶劣,气温低且昼夜温差大,该技术的应用将支撑川藏铁路优质高效地建设,为川藏铁路冬季严寒环境施工提供保障。

In terms of the welding construction of the bridge site of Heilongjiang Bridge in the cold winter environment at-48℃,combined with the structural characteristics of the transverse and longitudinal beams of Heilongjiang Bridge,the movable heating insulation shed was used,the industrial heater was used for heating in the shed,with tiled induction heating belt for preheating before welding,so that the welding environment and welding preheating could meet the process requirements.After welding,the post-heating measures were taken,a special welding process was adopted,and welding heat input was controlled to guarantee the welding quality.The results showed that for the high-performance weathering steel welded joints,the impact energy at-40℃KV2≥47 J,the impact energy at-60℃KU2≥47 J,and the atmospheric corrosion resistance index I≥6.0,which met the demands for winter welding of bridge steel beam manufacturing and the application requirements of non-painting.This method can be applied to winter welding construction of steel structures in other cold areas in China as well.For example,this technology can support the high-quality and efficient construction of the Sichuan-Tibet Railway,which is located in a plateau alpine area with a complex environment,bad climate low temperature,and a large temperature difference between day and night,and provide guarantees for construction in cold winters.