Effect of Solution Treatment and Aging on the Microstructures Mechanical Properties of K452 Alloy

The effect of solution treatment and aging on the microstructures and mechanical properties of K452 nickel based alloy is investigated in this paper. The research results indicate that after being held at 1170 ℃ for 4 hours and then cooled to 900℃ in the furnace, followed by water cooling for solution treatment, and subsequently heated to 1000 ℃ for 4 hours and water cooled for aging treatment. The hardness, tensile strength, and elongation of the K452 alloy increase by 7.8%, 8.4%, and 18.4% respectively compared to the as-cast state. However, after undergoing a secondary aging treatment involving heat preservation at 850 ℃ for 16 hours followed by water cooling, the microstructures of K452 alloy exhibited coarsening, leading to a decline in its mechanical properties. This is due to the appearance of η phase and γ' coarsening in the microstructure after secondary aging, and the increase in the spacing between the coarsened phases weakens the dislocation hindrance effect, resulting in stress concentration and a decrease in strength.