Effect of post-weld heat treatment on microstructure evolution and pitting corrosion behavior of UNS S31803 duplex stainless steel welds

► The content of austenite in the HAZ and WM is elevated after PWHT. ► Microstructure evolution in the welded zone is discussed in detail. ► Pitting morphologies evolution in the welded zone is discussed in detail. ► The optimum annealing temperature of the weld joints was determined. ► Areas around inclusions are easy to trigger pitting corrosion in chloride solution.