论文部分内容阅读
通过熔化极气体保护焊的方法,分别采用等强匹配和低强匹配焊丝对HG785钢进行对接焊,并对焊接接头拉伸、弯曲、冲击、硬度等力学性能进行了检测。结果表明,低强匹配接头抗拉强度在810 MPa左右,断裂位置均位于焊缝,接头背弯出现裂纹;等强匹配接头抗拉强度在840 MPa左右,断裂位置均位于HAZ,接头正弯、背弯均合格,接头塑性良好;低强匹配接头低温冲击韧性均优于等强匹配接头,随着试验温度降低,低强匹配接头焊缝冲击韧性降低速度小于等强匹配接头,说明采用低强匹配对于提高低温冲击韧性有利;低强匹配焊缝一定程度上减小了熔合线附近硬度的波动,使得焊缝和热影响区硬度趋于均匀分布,有利于降低接头应力集中。
HG785 steel was butt welded by isopach matching and low - strength matching welding wire respectively by means of melting gas welding. The mechanical properties such as tensile, bending, impact and hardness of welded joint were tested. The results show that the tensile strength of the low-strength matching joint is about 810 MPa, the fracture location is located at the weld, and the back bending of the joint is cracked. The tensile strength of the isopronic mating joint is about 840 MPa, the fracture position is located at the HAZ, Back bend are qualified, good plasticity joints; low-strength low-temperature impact toughness of adapters are better than the matching connector, with the lower test temperature, low-strength adapters weld joint toughness reduction speed less than the equivalent of matching connectors, indicating the use of low The matching is beneficial to improve the impact toughness at low temperature. The low-strength matching weld reduces the fluctuation of the hardness near the weld line to a certain degree, which makes the hardness of the weld and the HAZ uniform and reduces the stress concentration in the joint.