Equalization of Ti-6Al-4V alloy welded joint by scanning electron beam welding
(1. Institute of Metal Research, The Chinese Academy of Sciences,Shenyang110015, P.R. China；
2. State Key Lab for Corrosion and Protection, Institute of Corrosion and Protection of Metals,The Chinese Academy of Sciences, Shenyang110015, P.R. China)
2. State Key Lab for Corrosion and Protection, Institute of Corrosion and Protection of Metals,The Chinese Academy of Sciences, Shenyang110015, P.R. China)
Abstract: The equalization of Ti-6Al-4V alloy welded joint with base metal on corrosion resistance, strength and ductility was studied. The solidification microstructure is transformed from 650μm columnar grains to 100μm equiaxed grains by scanning electron beam welding. The anodic polarization curve of 150μm equiaxed grains coincides with that of base metal. Equal corrosion resistance between weld metal and base metal was obtained. Uniform microstructure and solute distribution are the basis of equalization. Corrosion rate of weld with 150μm equiaxed grains is the lowest, 2.45 times lower than that of 650μm columnar grains. Weld strength is 98% as much as that of base metal, yield-strength ratio is 99.5%, which is 3.6% higher than that of base metal.
Key words: scanning electron beam welding; titanium alloy; welding; equalization