The effect of large heat input on the microstructure and corrosion behaviour of simulated heat affected zone in 2205 duplex stainless steel

摘要

In the simulated heat affected zone of 2205 duplex stainless steels, effects of large welding heat inputs on the microstructure and corrosion behaviour were investigated. Reformed austenite content increased with the coarsening of grain boundary austenite (GBA) and the growth of intragranular austenite (IGA) and Widmanstatten austenite (WA), thus improving the low temperature toughness and affecting corro sion state. Reduction of chromium nitrides contributed to better resistance to pitting corrosion. More over, the pitting corrosion and intergranular corrosion were improved resulting from the formation of more GBA and WA. The specimen with a Ar8/5 of 100 s presents better comprehensive performance.