多次补焊对铝合金型材焊接接头力学性能的影响

Influence of multi-repair welding on the mechanical performance of hollow extruded profile aluminum alloy welded joints

针对中空铝合金挤压型材6005A薄壁对接接头在焊态下和分别进行1~3次焊接修补后的拉伸、弯曲、硬度和疲劳性能进行了测试实验和对比分析。结果表明,与焊态下相比,焊缝金属经过1~3次补焊后,焊接接头的抗拉强度和弯曲性能均符合标准规定的要求,接头延伸率变化不大但都低于母材延伸率。在焊态下和分别经过1次、2次补焊后,接头在寿命107周次条件下的疲劳极限也符合规范要求,但经3次补焊后的接头的疲劳极限未能达到要求值。硬度和拉伸实验均表明,在焊接接头的热影响区存在过时效软化区,且软化区为整个焊接接头最为薄弱的环节。

Experimental study and comparison analysis are conducted on 6005 A hollow extruded aluminum alloy profile thin-all butt welded joints under the conditions of original welding and one time,two-time,three-time repair welding respectively. The performances of tensile,bending,hardness and fatigue are tested. The results show that comparing to original welding state,the tensile strength and bending behaviors of the welded joints of repair welding meet the demands. The elongation rates of the welded joints of original welding and repair welding are similar,but both below the elongation rate of the base material. The 107-cycle fatigue limits of the welded joints of the original welding and one,two times repair welding also meet the requirements,while the fatigue limit of the welded joints of the three-time repair welding fail to reach the standards. The hardness and tensile tests also show that there is a soft zone both in the welded joints of original welding and repair welding,which is the most weakness part in the welded joints.