Precipitation and growth behavior of Fe₂Nb-type Laves precipitates are crucial for the mechanical behavior of FeCrAl-based cladding alloys containing Mo and Nb. In this study, the age hardening response of a Fe-13Cr-4Al-2Mo-1.2Nb alloy at 600–800 °C and the corresponding precipitation behavior were systematically investigated. The alloy exhibited a typical two-stage hardening behavior separated by a plateau during aging at all the temperatures. For the alloy aged at 700 °C, the total hardness increment by aging reached ~102.7 HV (40%), with an aging time of 60 min to reach the peak-aged state. Based on detailed transmission electron microscopy (TEM) investigations, the precipitation sequence of the alloy was elucidated as: Supersaturated solid solution → γ″ → γ' → C14-Fe₂(Nb,Mo) Laves phase. As the aging proceeded, the Fe₂(Nb,Mo) precipitates also evolved from a needle-like morphology with a semi-coherent interfacial structure into a short-rod-like and finally a blocky morphology with a non-coherent interfacial structure. The JMA equation describing the aging kinetics of the alloy was established. The apparent activation energy for the precipitation of the Fe₂(Nb,Mo) phase was calculated as 141.5 KJ/mol.

Fe ₂ Nb型Laves沉淀物的沉淀和生长行为对于包含Mo和Nb的FeCrAl基熔覆合金的力学行为至关重要。在这项研究中，系统地研究了Fe-13Cr-4Al-2Mo-1.2Nb合金在600–800°C时效硬化反应和相应的析出行为。该合金表现出典型的两阶段硬化行为，在所有温度下的时效过程中均被平台隔开。对于在700°C下时效的合金，时效后的总硬度增量达到〜102.7 HV（40％），时效时间为60分钟，达到峰值时效状态。根据详细的透射电子显微镜（TEM）研究，阐明了合金的沉淀顺序为：过饱和固溶体→γ''→γ'→C14-Fe ₂（Nb，Mo）Laves相。随着时效的进行，Fe ₂（Nb，Mo）析出物也从具有半相干界面结构的针状形态演变成短杆状，最终变为具有非相干界面结构的块状形态。建立描述合金时效动力学的JMA方程。计算出Fe ₂（Nb，Mo）相析出的表观活化能为141.5 KJ / mol。