TC4钛合金电子束焊接接头组织和性能

Microstructures and properties of TC4 alloy joints welded by the e lectron beam welding

通过室温拉伸、室温缺口拉伸、显微硬度以及金相分析对TC4钛合金电子束焊接接头的显微组织和性能进行了研究。试验结果表明,用电子束焊接TC4钛合金可获得性能良好的焊接接头,其接头的抗拉强度不低于母材,焊缝的缺口敏感系数均小于1。焊缝区和热影响区的硬度均高于母材,焊缝组织是由较粗大的原始β相转变而成的α′相,即针状马氏体,热影响区组织为均匀且细小的针状马氏体和原始α相的混合物。

Microstructures and properties of TC4 alloy joints welded by electron beam welding were investigated with room-temperature tensile test, room-temperature notch tension test, microhardness test and metallographic analysis. The results showed that the joints with good performance of TC4 alloy may be obtained by means of electron beam welding (EBW). The tensile strength of welded joint is not less than that of the base metal, and the notch sensitive coefficient of the welded joint is less than 1. The hardness of the welded joint and the HAZ are higher than that of the base metal. The microstructure of the weld metal is α′ phase (needle martensite) which was transformed from the primary coarse β matrix, and that of the HAZ was the mixture of fine needle martensite and the primary α phase.