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以镍为基的高温合金已在航空、舰船、电站、核反应堆以及石油化工等工业部门广泛应用。镍基高温合金除了必须满足一定的高温强度外,还必须同时满足下述两项要求:(1)合金在使用状态下具有良好的长期组织结构稳定性,以保证服役时维持较佳的综合机械性能;(2)在使用状态下有较强的表面化学稳定性,能经受住周围环境介质的侵蚀。但目前还没有一种镍基高温合金能同时满足这两项要求。为了使现有的高强度镍基合金既能充分发挥强度潜力,又能在苛刻的环境中表现出优越的抗蚀本领,国内外已广泛地对760℃以上长期使用的零件表面采用防护涂层。这样零件在服役过程中由合金作底材来提供强度,用涂层保证表面化学稳定性。据报导采用这一方法,可使燃气涡轮机的工作温度增高110℃左右。
Nickel-based superalloy has been widely used in aviation, ships, power plants, nuclear reactors and petrochemical industries. In addition to nickel-based superalloy must meet certain high temperature strength, but also must meet the following two requirements: (1) the alloy in use has good long-term structural stability, to ensure that service to maintain a better integrated machinery Performance; (2) In the use of the state has a strong chemical stability of the surface, can withstand the erosion of the surrounding media. However, at present, there is not a nickel-based superalloy that meets both of these requirements. In order to make the existing high-strength nickel-based alloy not only give full play to the strength potential, but also display excellent corrosion resistance in harsh environment, the protective coating has been widely used on the surface of components over 760 ℃ for long time . Such parts in the service process by the alloy as a substrate to provide strength, with the coating to ensure the chemical stability of the surface. It has been reported that using this method can increase the working temperature of the gas turbine by about 110 ° C.