大厚度TA31合金窄间隙焊接和电子束焊接对比研究

Study of Narrow Gap TIG Welding and Electron Beam Welding of Thick TA31 Alloy

进行了40 mm厚TA31合金窄间隙焊接和电子束焊接试验,实现了无缺陷焊接,并对比分析了两种接头组织性能。结果表明,窄间隙焊接接头宽13 mm,接头上下部组织均匀,焊缝区为粗大柱状晶,热影响区组织与焊缝类似;电子束焊接接头宽6 mm,接头上下部组织差异明显,焊缝区上部为粗大柱状晶,下部为等轴晶。上部热影响区出现片层α相,下部热影响区与母材类似。窄间隙焊接接头显微硬度峰值在热影响区,电子束焊接接头峰值在焊缝区。窄间隙焊接焊缝冲击值大于电子束焊接的,热影响区冲击值小于电子束焊接的;电子束焊接下部接头冲击值大于上部接头的。

The narrow gap and electron beam welding tests of 40-mm thick TA31 alloy were carried out, and defect-free welding achieved. Microstructure and mechanical properties of the two joints were compared and analyzed. The results show that the width of narrow gap welded joint is 13 mm, the microstructures of the upper and the lower of joint are evenly distributed, the weld zone consists of coarse columnar crystal, and the microstructure of the heat affected zone is similar to that of the weld zone. The width of electron beam joint is 6 mm, and the difference between the microstructures of the upper and the lower of joint are obvious. The upper part of the weld zone is the coarse columnar crystal and the lower part equiaxed crystal. Lamellarαphase is found in the upper heat affected zone, the microstructure of the lower heat affected zone is similar to that of the base metal. The microhardness peak of the narrow gap welded joint exists in the heat affected zone, and the peak of the electron beam welded joint exists in the weld zone. The impact value of the narrow gap weld is higher than that of the electron beam weld, the impact value of the heat affected zone is smaller than that of the electron beam. The impact value of the lower part of joint of the electron beam is higher than that of the upper part.