Structure and Pitting Corrosion of Ti-6Al-4V Alloy and Ti-6Al-4V Welds

The structure of Ti-6Al-4V alloy and Ti-6Al-4V weldments was examined. The welds were produced by hollow cathode arc discharge in vacuum using tantalum cathodes and different welding parameters. The corrosion behaviour of Ti-6Al-4V alloy and Ti-6Al-4V welds in solution containing Br- was evaluated quantitatively using potentiodynamic polarization tests. The corrosion behaviour of the base metal and welds was compared. Open circuit potential, pitting potential, corrosion current densities and corrosion rates were determined. The influence of the structure and its change during welding on corrosion behaviour is discussed in the present paper.