On the Hot Corrosion of Nickel at 700 °C

Thomas Gheno (1) , Brian Gleeson (1)

1 PITT - University of Pittsburgh

The reaction of nickel with Na2SO4 was studied in an O2-0.1SO2 atmosphere at 700 °C, conditions typical of type II hot corrosion. The interaction of NiO with the sulfate was thermodynamically analyzed and compared with the dissolution-precipitation process known to occur at higher temperatures. Here the dissolution stage was short-lived due to a positive solubility gradient for Ni 2+. The relatively fast growth of a NiO layer above a nickel sulfide layer was attributed to the inward molecular transport of SO2-SO3 through the porous NiO. The influence of environmental variables was further assessed by reacting nickel with and without Na2SO4 in air and then with no deposit in O2-0.1SO2. The roles of the deposit and atmosphere on the boundary conditions affecting the oxidation-sulfidation process were discussed on the basis of the observed reaction paths.

Mots clés: Nickel; Sodium sulfate; Hot corrosion; Sulfidation

Domaines: Matériaux

Thomas Gheno, Brian Gleeson. On the Hot Corrosion of Nickel at 700 °C. Oxidation of Metals, 2015, 84 (5-6), pp.567-584. ⟨10.1007/s11085-015-9588-6⟩. ⟨hal-01963863⟩