Electrolysis cell and a method for repairing same

An electrolysis cell of Hall-Héroult type for producing aluminium having prebaked anodes of a carbonaceous material, and a cathode structure comprising a pot shell made out of a steel material and further having a bottom and sides supported by structural elements such as cradles and beams, wherein the cathode structure further comprises a protective and insulating lining inside the shell and a carbon based cathodic bottom with collector bars embedded therein, and where produced aluminium metal forms a layer onto said cathodic bottom, an electrolytic bath positioned above said aluminium metal where the anodes are in electrical contact with said electrolyte, wherein at least part of the steel pot shell and/or deck plates are made of a ferritic stainless steel (FSS) material. The method relates to a repair procedure for replacing parts of a commonly used carbon steel material with ferritic stainless steel material at least in parts of the steel pot shell and/or deck plates heavily exposed to corrosion and detonation. The replacement procedure can either result in a homogenous or composite material structure in affected areas.