Q345R电子束焊接接头的组织与性能

Analysis on Q345R Vacuum EBW Butt Welds

研究了Q345R真空电子束焊接接头的力学性能及微观组织,并与焊条电弧焊对接接头进行了对比。研究显示,真空电子束焊接接头的焊缝硬度显著高于母材及焊条电弧焊的焊接接头,低温冲击韧性大幅降低,原因在于电子束焊接过程中产生的贝氏体组织硬度较高且韧性较差。采用高温回火热处理减少贝氏体组织,可显著改善Q345R电子束焊接接头冲击韧性和硬度。

This article studied the mechanical properties and microstructure of welded joints of Q345R welded by vacuum electron beam welding,and compared them with SMAW butt joints.It was found that the hardness of vacuum EBW weld metal were significantly higher than those of base metal and SMAW joints,while impact toughness was reduced.The main reason was that Bainite structure was produced during electron beam welding with high hardness and poor impact toughness.In order to improve the poor toughness of Q345R EBW joints,tempering heat treatment at elevated temperature was adopted to reduce the Bainite structure,and the impact toughness and hardness were improved significantly.