Effect of Short-Time Aging Treatment on Microstructure and Corrosion Resistance of 2205 Duplex Stainless Steel

2205 duplex stainless steel in the solid solution state was treated by short-time aging at 800 ℃ for different times (5-30 min), and the effect of aging time on the microstructure and corrosion resistance of the steel was studied. The results show that the content of σ precipitate en-riched in chromium, nickel and molybdenum increased, and the size increased with increasing aging time; the σ phase mainly distributed on the ferrite and austenite phase boundaries, and a small amount distributed inside the ferrite and austenite crystals. With increasing aging time, the intergranular corrosion sensitivity of the test steel increased, and the pitting corrosion potential decreased, indicating the intergranular corrosion resistance and pitting corrosion resistance decreased.