A material solution against fireside chloride corrosion

The paper describes the development of a new material solution to protect fireside surfaces against high temperature (500-700°C) chlorine corrosion in severe combustion environments of the energy and process industry. The proposed solution is based on introducing an innovative coating as a surface layer to prevent chlorine and oxygen diffusion into the substrate to be protected. For experimental verification of the concept, new coatings and hot isostatic pressed materials against chlorine corrosion (Cl-trap coatings) have been exposed to an aggressive chlorine environment at 600°C. The new Cl-trap materials with Ni barriers strongly retarded chlorine corrosion by preventing Cl penetration through lamellar boundaries into the substrate material. The required nearly pure Ni layers were not retained in the HIPed alloys that therefore did not perform equally well.