摘要
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-hardening type alloy with high strength, high-temperature and corrosion resistance, which is used widely in oil and gas, chemical industry, ocean and other engineering fields. Due to its complicated composition, the metallurgical and heat-treatment process has a decisive influence on the alloy＇s properties. This work adopted vacuum induced melting and electric slag remelting （VIM ＋ ESR）, forging and heat treatment process technologies to systematically study the composition, process, properties and the forged, solution-aging microstructures of the alloy with the characterization methods of X-ray fluorescence spectra, nitrogen-hydrogen-oxygen analyzer and scanning electron microscopy （ SEM ）. The results showed that the matrix and trace elements composition could be precisely controlled through VIM ＋ ESR duplex metallurgy process, and the forged alloy could obtain the best mechanical properties after solution at 980 - 1000 ℃ × 2 h and the following 730 - 760 ℃× 8 h aging treatment. The alloy＇s mechanical properties reached the level of Incoloy925 alloy. As aging at 660 - 760℃, the alloy strengthening depended mainly on the precipitated γ＇, γ＂and dispersed carbide phases; as aging at 780 - 860 ℃, the granular carbides aggregated and the acicular σ phases distributed continuously along the grain boundaries, which caused a sharp decline of the alloy＇s impact toughness. The research had an important guiding significance for the preparation and industrialization of the alloy.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2016年第9期882-889,共8页
Chinese Journal of Rare Metals
基金
河南省科技攻关项目(162102310400)
河南省高等学校重点科研项目(16A430002)
河南工程学院博士基金项目(D2015015)资助
