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通过蠕变曲线测定和组织形貌观察,研究FGH95合金的蠕变行为及影响因素。结果表明:经1150℃固溶和时效处理后,在晶界处有粗大γ′相不连续分布,其周围存在γ′相贫化区;经1165℃固溶和时效后,合金的晶粒尺寸明显长大,并在晶界形成连续的碳化物膜;经1160℃固溶后,合金中无粗大γ′相,在晶内弥散析出细小γ′相,其中,有粒状(Nb,Ti)C相在晶内及沿晶界不连续析出,可提高合金的晶界强度,抑制晶界滑移,是使合金具有较好蠕变抗力的主要原因。蠕变期间,合金的变形机制是位错剪切或绕过γ′相,蠕变后期,在晶内发生单取向和双取向滑移,并引起应力集中,致使裂纹在晶界处萌生及扩展是合金的蠕变断裂机制。
The creep behavior and influencing factors of FGH95 alloy were studied by creep curve and microstructure observation. The results show that after the solid solution treatment and aging treatment at 1150 ℃, the coarse γ ’phase is not continuously distributed in the grain boundary, and the γ’ phase depletion zone exists around it. After the solution and aging at 1165 ℃, the grain size Obviously grow up and form a continuous carbide film in the grain boundary. After the solid solution at 1160 ℃, there is no coarse γ ’phase in the alloy, and fine γ’ phase is precipitated in the grain, among which granular (Nb, Ti) C Phase in the grain and along the grain boundary is not continuous precipitation, can improve the grain boundary strength of the alloy, grain boundary slip inhibition is to make the alloy has a good creep resistance of the main reasons. During creep, the deformation mechanism of the alloy is dislocation shearing or bypassing the γ ’phase and the late creep phase. The unidirectional and double-orientation slip occurs in the crystal and causes the stress concentration, resulting in the initiation and propagation of the crack at the grain boundary Is the alloy creep rupture mechanism.