(西北有色金属研究院，西安 710016)
摘 要: 采用真空电子束焊接工艺研究CT20钛合金的焊接性能，分析电子束焊接过程中不同工艺参数对焊缝形状的影响。通过对显微组织的观察以及显微硬度和低温拉伸性能的测试，分析焊接接头显微组织、断口形貌及焊缝中气孔的形成。结果表明：CT20钛合金的焊接性能优良，焊接接头的抗拉强度达到785 MPa，断口部位位于热影响区；焊缝和靠近焊缝热影响区的显微组织均为典型的魏式组织，母材显微组织为块状初生α相和β转变组织构成的双态组织。采用真空电子束焊焊接的CT20合金板材，其焊缝的硬度值比母材的高，焊缝和热影响区中较粗大的原始β相一部分转变为过饱和的针状马氏体。
关键字: CT20钛合金；电子束焊接；显微组织
（Northwest Institute for Nonferrous Metal Research, Xi’an 710016, China）
Abstract:CT20 alloy plates was welded by using vacuum electron beam welding process, through observing the microstructure, testing the microhardness and the microstructure and property of welded joints, and the formation of porosities in the weld were analyzed. The results show that the porosities are formed in weld metal when CT20 alloy is welded by vacuum electron beam welding, the hardness value of weld metal is higher than that of the base metal, but the impact toughness value of the weld metal is lower than that of the base metal. The partial coarse original β phase in the weld and HAZ metals are changed into the supersaturated acicular martensite. There are a little acicular α′ phase in the middle of the weld metal, and the interlaced α structure is formed.
Key words: CT20 Ti alloy; electron beam welding; microstructure
