No abstract

Duplex stainless steels (DSS) have a microstructure of ferrite and austenite. These alloys have a high strength combined with ductility and good corrosion resistance. They are widely used in the petrochemical, paper and nuclear industries. However, like other stainless steels, they are susceptible to hydrogen embrittlement (HE). DSS 2205 samples were received under the condition of homogenization annealing (1050°C for 300 s and cooling in water). Then, they were cold rolled to 60% thickness reduction and annealed at 1100°C for 7200 s and aged at 850°C for 86400 s, then charged with hydrogen. Melt extraction analyzes were applied to quantify the hydrogen in the steel. In situ tensile tests, with simultaneous hydrogen charging, were used to assess the embrittlement caused by this element. Completing the hydrogen analyzes, thermal desorption spectra (TDS) were constructed. In the aged condition, the phases ferrite, austenite, sigma (σ), chi (χ) and carbide (M 23 C 6 ) were identified. The DSS showed a considerable reduction in ductility, reaching 5% total elongation in the aged state. Hydrogen charging did not change this condition. Melt extraction revealed a hydrogen content in the microstructure of up to 50 wppm for the annealed condition, while for the aged sample it was 10 wppm.