In metallurgy, the Bower–Barff process is a method of coating iron or steel with magnetic iron oxide, such as Fe<sub>2</sub>O<sub>4</sub>, in order to minimize atmospheric corrosion.
The articles to be treated are put into a closed retort and a current of superheated steam passed through for twenty minutes followed by a current of producer gas (carbon monoxide), to reduce any higher oxides that may have been formed.
The process is named for George Bower and Frederick S. Barff.
The Bower-Barff Rustless Iron Process, New York 1883.