熔体过热处理对M963合金组织和高温持久性能的影响

EFFECT OF MELT SUPERHEATING TREATMENT ON THE MICROSTRUCTURE AND HIGH TEMPERATURE STRESS RUPTURE PROPERTIES OF M963 SUPERALLOY

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 effect of melt superheating treatment on the microstructure and stress rupture properties of M963 superalloy under the condition of 1248 K/225 MPa has been investigated. The results show that with the increase of melt superheating temperature, the primary carbide MC in the as-cast condition becomes finer and more homogeneous gradually, and both the rupture life and elongation increase greatly. However, when the melt superheating temperature reaches 2023 K, the stress rupture performance of the superalloy is deteriorated due to the increase of gas content and microporosity. Both the rupture life and elongation of as-cast M963 superalloy under 1923 K melt superheating treatment and 1248 K/225 MPa can be doubled and even more.