T2紫铜-45钢异种材料电子束焊的焊接接头强度与缺陷评定

焊接接头性能与缺陷一直是焊接领域的重要课题，文中针对T2紫铜-45钢异种材料电子束焊的焊接接头强度和焊接缺陷的问题，首先采用SEM观测焊缝区域的微观形貌，分析其组织构成，并通过标准拉伸和三点弯曲试验，得到接头焊缝区的界面强度参数；其次依据断裂韧性值，开展了针对该异种材料试样内部缺陷的缺陷评定. 结果表明，采用电子束焊加工该异种材料，焊缝内部存在宏观偏析现象. 此外，依据表征得到的T2紫铜/45钢异种材料界面强度参数，验收通过了基于BS7910标准的2A级缺陷评定.

Study on welding strength and defect assessment of the T2 copper-45 steel dissimilar material

The performance and defect of welded joint has always been an important aspect in welding field. Previous researches mainly focus on the influence of brazing solder on welding strength. This project paid attention to the welding strength and defect of the T2 copper-45 steel dissimilar material. It was started with discussing micro-morphology of weld zone by SEM, following up with standard tensile and three-point bending experiments which were applied to obtain interface strength. In accordance with fracture toughness, a defection assessment was performed to provide the basis for enhancing welding joint strength. The results show that macro-segregation exists in the weld zone by using electron beam welding. According to interfacial strength characteristic of T2 copper/45 steel dissimilar materials, 2A level failure assessment based on BS7910 is applied and passed.