Galvanizing pre-treatment with hydrogen

Purpose - Before being galvanized, long products like tube, wire and strip need to be cleaned to remove oils and oxides that would inhibit the galvanizing process. Ideally, this process would be instantaneous so that production rates were not compromised and would require no energy. The purpose of this paper is to describe an investigation where rapid induction heating was combined with counter current flow of a hydrogen-rich atmosphere to reduce and evacuate surface oxides and residual drawing compounds before continuous galvanizing. Design/methodology/approach - Experiments were carried out to simulate the continuous hot-dip galvanizing of steel wire. Findings - The results suggested that, under the experimental conditions, lightly oxidized layers could be reduced in less than 2 s and give galvanized layers with good adhesion. High efficiency induction heating minimized the energy input required. Originality/value - The use of this technology can maximize galvanizing line speeds while maintaining quality with the minimum environmental impact.