氩气雾化制粉FGH97高温合金组织和性能研究

Study on Microstructure and Properties of Argon Atomization FGH97 P/M Superalloy

摘要:

利用扫描电子显微镜、金相显微镜等研究了氩气雾化制粉(Argon Atomization，AA )+热等静压(Hot Isothermal Pressing ，HIP)的FGH97合金显微组织、夹杂物、原始颗粒边界（Prior Particle Boundary，PPB）、热诱导孔洞（Thermally induced porosity，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。试验结果表明：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200nm，晶界γ′为1.5～2 μm的长方形，未见粗大γ′相及粗大碳化物。650℃/980MPa 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℃/980MPa持久性能以及650℃低周疲劳寿命均满足FGH97合金技术要求。

Abstract:

Characteristics of microstructure, inclusions, Prior Particle Boundary , Thermally Induced Porosity , defects and several large size disk′s tensile properties, stress rupture life ,low cycle fatigue of 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 to 2 μm. No coarse γ' phase and coarse carbides are observed. The average stress rupture time of 650 °C / 980MPa is 449 h. The maximum low cycle fatigue life is 258,909 cycles at 650 ℃, the average cycle reaches 19,014 cycles. The room temperature, 650℃, 750 ℃tensile properties, stress reputure performance at 650 ℃ / 980 MPa and the fracture life of Low cycle fatigue at 650 ℃ meet the FGH97 alloy technical requirements.