Failure Analysis of 316 Stainless Steel Corrosion Fatigue Test Fixture

The corrosion fatigue failure behavior of 316 stainless steel fixture used in high-temperature pressurized water environment was analyzed. The corrosion products, fracture morphology and stress distribution were performed using body microscope, scanning electron microscope, electron backscatter diffraction and finite element analysis. It was found that the stress concentration at the right-angle transition position of the fixture was obvious which promoted the corrosion damage during fatigue test in high-temperature pressurized water. Inclusions were also observed at the crack initiation positions and the propagation areas. The interaction between mechanical damage and environmental damage during fixture service was discussed, and a rounded corner transition was proposed and analyzed for retarding stress concentration at transition position of the fatigue fixture. Slip bands promote crack growth, and the direction of crack may propagate along these slip bands at the crack tip.