氩气雾化制粉FGH97高温合金的组织和性能

Microstructure and Properties of Argon Atomization FGH97 P/M Superalloy

利用扫描电子显微镜、金相显微镜等研究了氩气雾化制粉(AA)+热等静压(HIP)的FGH97合金显微组织、夹杂物、原始颗粒边界(PPB)、热诱导孔洞(TIP)等冶金缺陷,统计分析了室温、650、750℃拉伸性能、650℃/980MPa持久性能及650℃低周疲劳寿命。结果表明:AA+HIP+热处理制备的FGH97材料晶粒度为ASTM8~9级,未发现连续网状的PPB,存在极少量的TIP。晶内γ′多数为正方形,尺寸约为200 nm,晶界γ′为1.5~2μm的长方形,未见粗大γ′相及粗大碳化物。650℃/980 MPa持久时间均值449 h。650℃低周疲劳寿命最大值258909周次,均值达到190014周次。室温、650℃、750℃拉伸性能、650℃/980 MPa持久性能以及650℃低周疲劳寿命均满足FGH97合金技术要求。

The microstructure, inclusions, prior particle boundary, thermally induced porosity, defects and the tensile properties, stress rupture life, low cycle fatigue of large size disk for a P/M superalloy FGH97, which was made by argon atomization(AA)+hot isostatic pressing(HIP) process, were investigated. The results reveal that the grain size of FGH97 material prepared by AA+HIP+heat treatment is ASTM 8~9. No continuous network PPB is found, and there is a very small amount of TIP. The size of mostly square γ’ is about 200 nm, and grain boundary γ’ is 1.5~2 μm. No coarse γ’ phase and coarse carbides are observed. The average stress rupture time of 650 °C/980 MPa is 449 h. The maximum low cycle fatigue life is 258 909 cycles at 650 °C, and the average cycle reaches 190 014 cycles. The room temperature, 650, 750 °C tensile properties, stress rupture performance at 650 °C/980 MPa and the fracture life of low cycle fatigue at 650 °C meet the FGH97 alloy technical requirements.