Effect of Solution Treatment on Microstructure and Properties of GH3625 Alloy Tubes in Different States

Abstract

The influence of solution treatment temperature on microstructure evolution and mechanical properties of the GH3625 alloy tubes in different states (hot extrusion, cold rolled and annealed) were investigated by organization characterization(OM, SEM) and performance tests (hardness test and tensile test at room temperature). The results showed that the mixed grain structure of the hot extruded GH3625 alloy degraded and transformed into uniform equiaxed grain structure, as the solution treatment temperature was 1000 °C. When the solution temperature was higher than 1050 °C, the microstructure of the cold rolling GH3625 alloy was uniform equiaxed grain, and the solution amount of the carbides increases with the increase of the solution temperature. The microstructure of annealed GH3625 alloy in the whole solution temperature range (950–1150 °C) was fully recrystallized equiaxed grain, and there were a large number of lath-shaped annealed twins in the grains. The microstructure and mechanical properties of the GH3625 alloy during the solution treatment were not only affected by the solution temperature, but also influenced by the original states. After solid solution treatment at 1150 °C for 60 min and then water-cooling, the tensile fracture modes of GH3625 alloy tubes under different conditions was ductile fracture. The temperature of 1150 °C can be used as the reference temperature for optimizing the microstructure and properties of GH3625 alloy through solution treatment in different states.