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Fe-Ni-Cr合金是一种时效强化型高强度高温耐蚀合金,在油气、化工、海洋等工程领域有着广泛的应用。由于其成分复杂,冶金和热处理工艺对合金性能具有决定性的影响。本文采用真空熔炼(VIM)+电渣重熔(ESR)、锻造和热处理等工艺方法,通过X荧光光谱、氮氢氧分析仪、扫描电镜(SEM)等分析表征,对该合金的成分、工艺、性能以及锻态、固溶+时效态热处理组织进行了系统研究。研究发现,VIM+ESR双联冶金工艺可以有效实现基体成分、微量元素的精确控制,合金经锻造在980~1000℃×2 h固溶,继以730~760℃×8 h时效处理后可以获得最佳的力学性能,其力学性能达到国际Incoloy925水平;时效温度在660~760℃时,合金主要以γ’,γ″和弥散碳化物析出强化为主;在780~860℃时析出颗粒状碳化物呈现聚集分布和针状σ相沿晶界连续分布,造成合金冲击韧性急剧下降。研究结果为该合金的制备及产业化具有重要的指导意义。
Fe-Ni-Cr alloy is a kind of aging strengthened high strength and high temperature corrosion resistant alloy, which has a wide range of applications in the field of oil and gas, chemical industry, marine and other engineering. Due to its complex composition, metallurgical and heat treatment processes have a decisive influence on the properties of the alloy. In this paper, VIM + electroslag remelting (ESR), forging and heat treatment methods were used to characterize the composition and process of the alloy by X-ray fluorescence spectroscopy, nitrogen and hydrogen analyzer, scanning electron microscopy (SEM) , Performance and forgings, solid solution + aging heat treatment organizations were systematically studied. The results show that VIM + ESR double metallurgy can effectively control the matrix composition and trace elements. The alloy can be obtained by forging at 980 ~ 1000 ℃ for 2 h and subsequent aging treatment at 730 ~ 760 ℃ for 8 h The best mechanical properties, the mechanical properties of the international Incoloy925 level; aging temperature of 660 ~ 760 ℃, the alloy mainly γ ’, γ "and precipitation of precipitation-based carbide precipitation; precipitated at 780 ~ 860 ℃ granular carbonization The distribution of aggregates and the distribution of acicular σ phase along the grain boundaries are continuous, resulting in a sharp decrease in the impact toughness of the alloy.The results of the study have important guiding significance for the preparation and industrialization of the alloy.