高温合金GH4169与GH4202在富氧气氛中的燃烧行为

采用富氧燃烧实验方法,通过光学显微镜、扫描电子显微镜和能谱仪等手段对GH4169和GH4202高温合金燃烧试样进行分析,建立合金燃烧质量、热量和氧传输模型,探究两种合金的富氧燃烧机理并提出提高新型高温合金抗燃烧性能的措施。结果表明：GH4202与GH4169合金在富氧条件下均发生燃烧,GH4202抗燃烧性能优于GH4169；两种合金以液相进行燃烧,在合金燃烧前沿存在由未完全燃烧的金属颗粒和氧化物组成“燃烧层”,燃烧层中合金元素的燃烧行为是决定合金整体燃烧的关键性因素；合金元素在燃烧前沿呈现“选择性燃烧”规律,Nb、Ti、Al、Cr等元素易于与氧发生燃烧,Ni滞后燃烧且燃烧热低,起到良好的抗燃烧作用。

Combustion behavior of GH4169 and GH4202 superalloys in oxygen-enriched atmosphere

Ignition-combustion test was carried out and the combustion samples of GH4169 and GH4202 superalloys were ana-lyzed by using optical microscopy, scanning electron microscopy and energy dispersive spectrometry. A model of mass transfer, heat transfer and oxygen transfer was built to analyze the combustion mechanism of the alloys. Some methods to improve the ability of com-bustion resistance for new superalloys were proposed. The results show that both the alloys burn in the test condition, but GH4202 per-forms better than GH4169. Both the alloys burn in liquid phase, there is a combustion section composed of oxides and metal particles in front of the reaction zone, and the burning behavior of elements in the combustion section decides the combustion ability of the whole alloys. A selective combustion rule of elements is present in the combustion section, the elements such as Nb, Ti, Al and Cr will burn with oxygen easily, while Ni is of delayed combust with low heat and can protect the alloy from combustion.