对M963合金熔体进行了过热处理并在1248 K/225 MPa条件下测试了其持久性能.结果表明:随熔体过热温度的升高,铸态组织中的初生MC碳化物不断细化和均匀分布,合金的持久断裂寿命和塑性明显提高;但温度高达2023 K的熔体过热处理,使合金中的气体含量升高,导致显微疏松增加,持久性能降低.在1923 K温度下进行熔体过热处理,可使M963合金在1248 K/225 MPa条件下的持久寿命和持久塑性同时提高一倍以上. The M963 alloy melt was overheated and its ductility was tested at 1248 K / 225 MPa.The results showed that the primary MC carbides in the as-cast microstructure were refined and homogenized with the increase of the melt overheat temperature Distribution, the long-term fracture life and plasticity of the alloy significantly improved; but the melt overheating up to 2023 K, the gas content of the alloy increased, resulting in increased microscopic porosity, lasting performance decreases at 1923 K temperature melt Overheating allows the M963 alloy to more than double the long-term durability and ductility at 1248 K / 225 MPa at the same time.