FGH4113A粉末高温合金的裂纹扩展性能研究

Crack Propagation Properties of FGH4113A Powder High-Temperature Alloy

摘要:

对自主研发的第三代粉末高温合金FGH4113A的裂纹扩展性能进行了研究,包括制备工艺、温度、加载频率对裂纹扩展性能的影响,并与国内外同类高温合金进行了比较。采用热等静压(HIP)、热挤压(HEX)、等温锻造(ITF)与热处理(HT)的组合工艺制备合金,实验测试温度包含室温、650℃、700℃,加载频率有0.33Hz与20Hz ,分析了工艺、温度、加载频率对合金高温裂纹扩展性能的影响,对比了同类合金牌号FGH95、FGH96、FGH97、FGH98、ME3、LSHR的裂纹扩展性能。结果表明：PPB和晶界周围粗大的一次γ′相是合金裂纹扩展性能的不利因素,增大合金晶粒尺寸有利于降低裂纹扩展速率。挤压与锻造工艺能够有效消除PPB,从而提高合金的抗裂纹扩展能力。室温裂纹扩展速率远低于650℃和750℃的裂纹扩展速率,合金0.33Hz测试频率的裂纹扩展速率明显高于20Hz,升高温度与降低测试频率均会增大合金的裂纹扩展速率。ITF态FGH4113A合金在稳定裂纹扩展阶段超出FGH98、LSHR和ME3合金,达到了国际上第三代粉末高温合金的先进水平。

Abstract:

The crack propagation performance of the independently developed 3rd generation powder high-temperature alloy FGH4113A was studied, including the effects of preparation process, temperature, and frequency on crack propagation performance, and a comparison was made with similar high-temperature alloys internationally. The preparation process involved a combination of Hot Isostatic Pressing (HIP), Hot Extrusion (HEX), Isothermal Forging (ITF), and Heat Treatment (HT). Test temperatures included room temperature, 650°C, and 700°C, with test frequencies of 0.33Hz and 20Hz, analyzing the impact of frequency on the alloy"s high-temperature crack propagation performance. The comparison included similar alloy grades such as FGH95, FGH96, FGH97, FGH98, ME3, and LSHR. The results show that ppb and coarse primary γ′ phase around the grain boundary are unfavorable factors for the crack growth performance of the alloy, and increasing the grain size of the alloy is beneficial to reducing the crack growth rate. Extrusion and forging process can effectively eliminate PPB, thereby enhancing the alloy"s crack propagation resistance. The crack growth rate at room temperature is much lower than that at 650 ℃ and 750 ℃, and the crack growth rate at 0.33hz test frequency is significantly higher than that at 20Hz. Increasing the temperature and decreasing the test frequency will increase the crack growth rate of the alloy. In the stable crack propagation stage, the ITF state FGH4113A alloy exceed FGH98, LSHR and ME3 alloys, and reach the advanced level of the 3rd Powder Superalloy.