热处理工艺对GH4169高温合金组织与力学性能的影响

Effects of Heat Treatment Process on Microstructure and Mechanical Properties of GH4169 Superalloy

采用两种典型热处理工艺研究了GH4169高温合金的显微组织演变和力学性能。结果表明:相比于热轧态力学性能,热处理工艺显著提高了GH4169高温合金的屈服强度,这主要归因于热处理过程中析出相的强化作用。标准热处理不仅能够获得更高的室温强度且维持了高温强度;但高强热处理却有效改善了冲击韧性。固溶温度的提高,导致δ相溶解以及奥氏体晶粒尺寸的粗化,削弱了细晶强化效果,这是高强热处理态试样强度下降的主要原因。尽管从冲击断口形貌来看,两种热处理态试样均呈微孔聚集型断裂方式,但高强热处理的韧窝尺寸更深,有利于提高冲击韧性。

The microstructure evolution and mechanical properties of GH4169 superalloy were studied using two typical heat treatment processes.The results indicate that,the yield strength of GH4169 superalloy are significantly increased under the heat treatment process compared with that of the hot rolled state,mainly due to the strengthening effect of the precipitated phases during the heat treatment.Standard heat treatment not only achieves higher strength at room temperature but also maintains high temperature strength,but the high-strength heat treatment effectively improves the impact toughness.The increase of the solid solution temperature leads to theδphase dissolution and the coarsening of the austenite grain size,which weakens the strengthening effect of the fine crystals,this is the main reason for the decrease in sample strength in high-strength heat treatment states.Although from the perspective of impact fracture morphology,both heat-treated state samples show a microporous aggregate fracture mode,the toughness size of high strength heat treatment is deeper,which is beneficial to improve the impact toughness.