Oxidation and oxide film coking behavior of GH605 high temperature alloy in air

Coking and carbon deposition on aircraft engine nozzles could cause poor fuel atomization effect, low combustion efficiency, and even seriously endanger the safety of aircraft. The high temperature oxidation characteristics of GH605 alloy at different temperatures were studied using air as the oxidation atmosphere, and the effect of alloy surface state on coking behavior at high temperatures was investigated using RP-3 aviation kerosene as raw material. The results show that as the oxidation temperature increased, the oxide film on the alloy surface was mainly composed of chromium rich oxide and (Co,Ni,Mn)Cr₂O₄ spinel, with fewer W and Ni elements. The alloy had good high temperature oxidation resistance. The oxide film contained a small amount of Co catalytic elements, and the typical catalytic coking mechanism was still dominant in the initial stage of surface coking. Later, it transformed into a non-catalytic coking mechanism, and the coke appeared as amorphous particles.