The influence of a propane gas torch flame post-weld heat treatment on the mechanical and corrosion properties of a 2219-T87 friction stir weld

A propane torch post-weld heat treatment followed by an overaging treatment has been applied to a 2219-T87 friction stir weld in order to determine the influence on the microstructure, mechanical properties, corrosion and environmental cracking behaviour. The mechanical properties were investigated by means of tensile and Charpy impact tests, while the corrosion behaviour and the environmental cracking susceptibility were studied with corrosion immersion tests in a NaCl/H₂O₂ solution at 30°C and with constant extension rate tests respectively. The propane torch postweld heat treatment represented a short-term heat treatment which promoted the dissolution of the grain boundary phases, a homogenisation of the microstructure of the weld microzones, positively affected the tensile properties, the corrosion and the environmental cracking behaviour of the 2219 FSW weld.