In this paper, pack cementation has been applied to prepare aluminized coatings on AISI 321 stainless steel. The effect of aluminizing process and subsequent annealing treatment on the creep properties and life prediction of AISI 321 was investigated at 620 °C. The results reveal that the coatings of aluminized steel are incorporated by a top inhomogeneous Al₂O₃, a Fe-Al intermetallic compound layer and subsequent Fe(Al) solid solution layer. In addition, the coatings thickness increased apparently after annealing. The reduction of effective bearing area due to the formation of defects around NiAl at coatings and the intrinsic brittle nature of the coating are responsible for the degradation of creep lives for aluminizing steel in comparison to that of as-received steel. During creep deformation, M₂₃C₆ and TiC precipitated at austenitic grain interior would produce dislocations radially, indicating deformation mechanism of aluminized steel domains by dislocation–dislocation interactions. However, annealed steel exhibits a discernable improved creep performance since twin boundary factions induced by annealing are as twice as before. In the creep process, tangled dislocations interact with twin boundaries, leading to the formation of weaken zones within twined region. Compared with other theories, θ-projection method has outstanding ability to predict the creep life of materials due to its adequate parameters defined to describe three typical stages of creep curve admirably.

在本文中，填充胶结已应用于在 AISI 321 不锈钢上制备镀铝涂层。在 620 °C 下研究了渗铝工艺和后续退火处理对 AISI 321 蠕变性能和寿命预测的影响。结果表明，镀铝钢的涂层由顶部不均匀的 Al ₂ O ₃, Fe-Al 金属间化合物层和随后的 Fe(Al) 固溶体层。此外，退火后涂层厚度明显增加。由于涂层处 NiAl 周围缺陷的形成和涂层固有的脆性，有效承载面积的减少是渗铝钢与原样钢相比蠕变寿命降低的原因。在蠕变变形过程中，M ₂₃ C ₆和在奥氏体晶粒内部析出的 TiC 会产生径向位错，表明通过位错 - 位错相互作用的渗铝钢畴变形机制。然而，退火钢表现出明显改善的蠕变性能，因为退火引起的孪晶边界是以前的两倍。在蠕变过程中，缠结位错与孪晶界相互作用，导致在缠绕区内形成弱化带。与其他理论相比，θ-投影方法具有出色的预测材料蠕变寿命的能力，因为它定义了足够的参数，可以很好地描述蠕变曲线的三个典型阶段。