Corrosion Behavior of GH4169 Alloy in NaCl Solution Spray Environment at 600℃
The corrosion behavior of engine materials of airplanes working in marine environments is accelerated by the synergistic effects of NaCl particles and water vapor at high temperatures.This work examined the corrosion behavior of GH4169 alloy with a NaCl solution spraying at 600℃ using an oxidation kinetics test and micro characterization technology in the aspects of corrosion kinetics,corro-sion layer phase composition,and microstructure.The weight gain of the GH4169 alloy corroded in the NaCl solution spraying environment was much lower than that in solid NaCl + wet O2 after 20 h corrosion at 600℃.The corrosion products of the GH4169 alloy in the NaCl solution spray environment were less complex than those in the solid NaCl + wet O2 environment,but they were denser.In addition,Cl was con-centrated in the inner layer of the corrosion products and accelerated the corrosion of GH4169 alloy via an"active oxidation"mechanism at the initial stage.When NaCl deposition was increased,the corrosion mechanism of GH4169 alloy changed gradually to Cl-induced"active oxidation."The sensitivity of GH4169 alloy in the NaCl solution spray environment at 600℃ was analyzed.Overall,the sensitivity of el-ements in GH4169 alloy to chlorine activated corrosion was Ti>Al>Nb,Cr>Fe>Mo,Ni,whereas the sensitivity of the oxides was TiO2>MoO2>Cr2O3(Nb2O5)>Fe2O3>Al2O3>NiO.
GH4169 alloyNaCl solution spraysensitivity of alloy element