Abstract: The microstructure and mechanical properties of superalloy GH1131 after multiple vacuum solution treatments at 1100-1170 ℃ were studied by using vacuum high-pressure gas quenching process. The results show that the solution treated microstructure contains austenite grains and carbide particles, and the grain size tends to increase with the increase of solution treatment temperatures. After multiple vacuum solution treatments, the microstructure of superalloy GH1131 is homogeneous and the mechanical properties at room temperature and 900 ℃ are stable. The grain size of superalloy GH1131 maintains grades 6-8 after three times vacuum solution heat treatments of 1100 ℃+1130 ℃+1170 ℃, and the tensile strength at 900 ℃ reaches 200 MPa.

Key words: superalloy GH1131, vacuum solution treatment, microstructure, mechanical properties