Effect of solid solution treatment on microstructure and corrosion properties of TIG weld of S31803 steel

The microstructure,hardness and electrochemical corrosion properties of TIG multilayer weld for S31803 duplex stainless steel under different solution temperatures were studied by optical microscope,Vickers hardness tester and electrochemical analysis. The test results showed that the TIG multi-layer weld of S31803 duplex stainless steel was mainly composed of austenite and ferrite,and a small amount of σphase also appeared in the multi-layer weld,while the austenite content in the lower bead was obviously lower than that in the upper bead.After solid solution treatment,the content of austenite and ferrite were close,and σ phase disappeared after solution treatment at 1 050 ℃ .However,with the increase of solid solution temperature,the proportion of austenite also increased. The hardness of the upper and lower layers of the weld tended to be close to each other due to solution treatment. After solution treatment at 950 ℃,the hardness of the weld slightly increased,while after solution treatment at 1 050 ℃,the hardness of the weld decreased. In addition,with the increase of solid solution temperature,the corrosion resistance of weld was better,and when the solid solution temperature was 1 050 ℃,the corrosion resistance was the best.