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文中总结了目前国内外先进超超临界(A-USC)锅炉关键部件用候选合金(Inconel 740/740H、CCA 617、Nomonic263、Haynes 230及GH 2984等)经标准热处理、无应力时效及持久实验后的组织特征和演化规律。结果表明:这类材料为了满足部件服役条件下对高温强度的要求,多采用析出强化设计,析出相种类繁多(如γ’、η、σ、μ及G相等);这些析出相的形貌、数量、尺寸及相间元素的分布等在高温长期时效或服役条件下均会发生明显变化,从而对合金的性能和服役行为产生重要影响。提出有必要进一步分析上述各相的演变规律及其作用,通过调整合金成分或热处理制度来优化组织结构,抑制或消除有害相的析出,提高合金的高温性能。
This paper summarizes the results of standard heat treatment, stress-free aging and long-term experiment of candidate alloys (Inconel 740 / 740H, CCA 617, Nomonic 263, Haynes 230 and GH 2984) for the key components of advanced ultra-supercritical (A-USC) The organizational characteristics and evolution of the law. The results show that, in order to meet the requirement of high temperature strength for service conditions of components, the precipitation hardening design is adopted to increase the variety of precipitates (such as γ ’, η, σ, μ and G). The morphology, The number, size and phase distribution of the elements will obviously change under long-term aging or service conditions of high temperature, which will have an important influence on the performance and service performance of the alloy. It is suggested that it is necessary to further analyze the evolution law and its role of the above phases, and to optimize the structure of the alloy by adjusting the alloy composition or heat treatment system to suppress or eliminate the precipitation of harmful phase and improve the high temperature performance of the alloy.