Effect of Precipitate Phases and Grain Size on Mechanical Properties of Inconel 718 Superalloy After Various Heat Treatments

不同热处理下析出相和晶粒尺寸对Incone1718高温合金力学性能的影响

Various heat treatments were conducted on Inconel 718 superalloy,and the resultant microstructures and properties were investigated to analyze the mechanisms of heat treatments.Results show that the type and quantity of precipitate phases and the grain size have different effects on the properties of Inconel 718 superalloy after various heat treatments.Theγ"andγ'phases as well as grain size mainly influence the strength,and theδphase mainly influences the plasticity.Besides,the precipitation ofγ"andγ'strengthening phases can improve the yield strength.The alloy strength is inversely proportional to mean grain size when theγ"andγ'phases have similar contents.The plasticity is susceptible to the content and shape ofδphase.A proper amount ofδphase is beneficial to the plasticity,but excessiveδphase degrades plasticity.

采用不同热处理工艺对Inconel 718高温合金进行了组织观察和性能研究以分析热处理机理。结果表明,析出相的类型和数量以及晶粒尺寸对Inconel 718高温合金热处理试样的性能有不同的影响。γ"相和γ'相以及晶粒尺寸主要影响强度,δ相主要影响塑性。此外,γ"和γ'强化相的析出可以提高屈服强度。合金中γ"和γ'相含量相近时,强度与平均晶粒尺寸成反比。塑性易受δ相含量和形状的影响。适量的δ相对塑性有益,但过量的δ相会使塑性降低。