Abstract: Solution and aging treatments of 15-5PH stainless steel were carried out by using vacuum hydrogen annealing furnace on the basis of H485, H495, H550, H580 and H620 processes in GJB 8268-2014 Specification for precipitation-hardening stainless steel bars for aviation, and the impact and tensile properties at room temperature and -50 ℃ low temperature were studied. The results show that with the increase of aging temperature, the tensile strengths of the 15-5PH steel at room temperature and low temperature decrease, and the impact absorbed energy and elongation increase gradually. The low temperature impact property of the 15-5PH steel under H485 process is the worst, and the lowest impact absorbed energy is about 10 J. The low temperature impact property under H550 process is significantly increased, the impact absorbed energy is increased to 72 J, and the low temperature tensile strength is about 1200 MPa, which shows good comprehensive mechanical properties.

Key words: 15-5PH stainless steel, aging, low temperature, tensile property, impact property