A process for producing an anti-erosion coating on an inner or outer metal wall of a chamber of a fluid catalytic cracking unit, comprising: (i) the shaping of a honeycomb metal anchoring structure, said anchoring structure being formed from a plurality of strips connected in pairs by joining assembly portions of these strips so as to form a plurality of cells between two adjacent strips, (ii) the fastening of said anchoring structure by welding to said metal wall, so that each cell of the anchoring structure is welded to the wall of the chamber at least at the junctions between the contiguous assembly portions of two adjacent strips, and (iii) the insertion of a composite material into the cells from the metal wall and at least up to the upper longitudinal edge of each strip.