本文较详细地研究了一种铁镍铬基合金长期时效过程中力学性能变化与组织结构的关系。合金的缺口敏感性与薄膜状TiC沿晶界析出有着密切的关系,随着时效温度的提高和时效时间的延长,晶界薄膜状TiC逐渐变为块状,因而缺口敏感得以消除。由于σ相数量很少,并呈块状分布,因此它能提高高温拉伸塑性及持久延伸率,对消除缺口敏感性也起到一定有利作用,但使室温拉伸塑性及室温冲击韧性下降,其不良影响比TiC及硼化物要小。 This paper studies in more detail the relationship between mechanical properties and microstructure of a Fe-Ni-Cr based alloy during long-term aging. The notch sensitivity of the alloy is closely related to the grain boundary precipitation along the TiC film. With the increase of the aging temperature and the aging time, the TiC in the grain boundary gradually becomes block, and thus the notch sensitivity can be eliminated. Due to the small amount of sigma phase and the block-like distribution, it can improve high-temperature tensile ductility and long-term elongation, and also play an advantageous role in eliminating the notch sensitivity. However, the tensile plasticity at room temperature and the room temperature impact toughness decrease, Its adverse effects than TiC and boride to be small.