IMPACT TOUGHNESS ENHANCEMENT OF AN ELECTRON BEAM WELDED Ti-6Al-4V TITANIUM ALLOY THROUGH POST-WELDING HEAT TREATMENT

摘要

Impact toughness of an electron beam welded Ti-6Al-4V titanium alloy in the α+ β annealed condition has been studied as-welded and after post-welding heat treatment (PWHT). The aim of this investigation is to have, through this PWHT, a great improvement of certain properties, and so to exhibit in the same time good ductility and superior fracture toughness as the one shown by β annealed Ti-6Al-4V alloy. The toughness of the base metal and of the weld has been evaluated using instrumented Charpy impact test. The supertransus PWHT leads to a homogeneous Widmanstatten microstructure between the fusion zone and the base metal which increase crack path length and allows obtaining higher impact toughness in the entire specimen.