Abstract:The structure of hot corrosion cell was changed with the increasing of porous oxides in products during the process of hot corrosion,it was macro cell that took main role in the direction vertical to the surface of samples.Anode reaction took place at the metal/compact oxide film interface,cathode reduction reaction took place at the molten salt+porous oxide/gas interface.The interfaces of porous oxide+molten salt/gas and metal+compact oxide film/molten salt were simulated,the acidity and basicity and oxygen activity were measured at both interfaces with time.It was shown that the gradient of basicity was positive in the salt film.The oxygen activity was decreased at the metal+compact oxide film/molten salt interface with time.

Key words: macro cell; basicity gradient; oxygen activity