2020 Volume 69 Issue 10 Pages 262-270
Coated steel structures are periodically re-coated due to deterioration of the coated film. To obtain a good resistance to corrosion after re-coating requires a fully sufficient removal of rust and residual film from the steel plate surface, through preparation of that surface. Clarification of the post-coating corrosion resistance of steel plate with an adherence of metal constituents deriving from the plated film and wire material will presumably provide knowledge useful for establishing the optimal method for surface preparation. This study consequently examined the effect exerted on post-coating corrosion resistance by metal constituents adhering to the steel plate surface. It found that coated steel plate whose surface had been prepared with a zinc-plated wire brush yielded a good resistance to corrosion as compared to other coated steel plate. To determine the cause, an examination was made from the perspectives of electrochemical properties, composition analysis, and surface free energy. The results indicated the possibility that corrosion products in the slight traces of zinc adhering to the steel plate may have curtailed the progress of corrosion by acting as a barrier to the diffusion of oxygen.
