A process for providing a corrosion resistant coating on uncoated ferrous components, involving mechanical plating, using as a coating medium a zinc metal-containing powder, such as zinc or zinc alloy powder, or a powder mixture of zinc or zinc alloy and at least one other metal, so as to build up a firmly adherent coating of the coating medium over exposed surfaces of the components, heating the components with the firmly adherent coating to produce solid-solid diffusion to form an Fe/Zn intermetallic over the surfaces, at least in a base layer of the coating built up by the plating, and cooling the components.