A1对GH4169合金冲击性能的影响

Effect of A1on impact strength of GH4169 alloy

研究了A1对GH4169合金晶界相的析出和冲击性能的影响.结果表明,提高Al含量可抑制晶界δ相的析出,促进晶界Laves相、M_7C_3相和σ相等有害相的析出;随着Al含量的提高,GH4169合金的室温冲击性能明显降低,冲击断口由穿晶型转变为沿晶型.提高Al含量所导致的Laves相等有害脆性相的析出降低了晶界强度,使晶界裂纹更容易萌生和扩展,降低了GH4169合金的冲击韧性.

The effect of AI on the grain boundary precipitation and impact toughness of GH4169 alloy was investigated. The delta phase precipitation at the grain boundaries is noticeably suppressed due to the increasing Al addition, and some harmful phases including Laves phase, M7C3 carbide and sigma phase are formed intergranularly. As a result, the ‘U＇ notch impact energy is largely decreased. The cracks incline to be initiated and propagated at the carbides and other harmful phases precipitated along the grain boundaries, and hence the fracture energy of the alloy with higher AI contents is reduced.