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.