INCONEL 617 合金的高温时效析出相

INCONEL 617合金（简称617合金）具有较好的高温强度、塑性以及良好的抗氧化、抗腐蚀性能,故可作为超超临界机组耐高温候选材料。为进一步了解617合金长期高温时效后的析出相及其组织结构,在760 ℃下对该合金进行长达10 000 h的时效试验,借助扫描电镜和透射电镜等分析设备研究 617合金高温时效处理（简称时效）后的析出相。结果表明：在760 ℃时效10 000 h过程中, 617合金析出面心立方结构的M₂₃C₆、M₆C碳化物和面心立方有序结构的γ′相,γ′相分布于晶内,M₂₃C₆和M₆C碳化物在晶界和晶内均有析出;整个时效过程晶内析出相基本稳定;时效300~3 000 h过程中,晶界析出相均呈不连续分布,时效至5 000 h,晶界碳化物聚集且连续分布,晶界M₆C碳化物数量明显增多;时效300 h后硬度明显升高,时效1 000 h后硬度达到最大值,时效5 000 h后硬度有一定幅度降低。

Precipitates in INCONEL alloy 617 aged at high temperature

The precipitates of the aged alloys were investigated by means of scanning electron microscope(SEM)and transmission electron microscope(TEM).The results show that M23C6 and M6C particles with face-centered cubic(FCC)structure precipitate at grain boundaries,inside grains and the γ′ phase particles with order FCC structure were situated at intragranular sites in the process of aging up to 10 000 h at 760 ℃.During aging up to 10 000 h,the precipitates inside grains remained basically stable.Precipitates discontinuously dispersed at grain boundaries for the alloy aged for 300~3 000 h,then aggregated and distributed continuously after 5 000 h aging.At the same time,the quantity of M6C carbides increased substantially for the alloy aged for 5 000 h.The hardness of the alloy aged for 300 h increased substantially,then a maximum hardness value for the alloy aged for 1 000 h was achieved accompanying by a decrease of the hardness of the alloy aged at 5 000 h.