On the Role of Nickel in Porcelain Enameling

Nickel applied to a sheet steel as a nickel flash endures in the surface through several de‐enamelings and re‐enamelings. The attendant improvement in the enameling behavior of the steel is similarly persistent. Heat‐treating experiments with and without nickel lead to the conclusion that, while the fired ensemble is cooling, nickel oxide at the interface is reduced by hydrogen issuing from the steel, forming water which enters the enamel and diminishing the hydrogen available for defect production. In this function, a cobalt layer is comparatively ineffective.