Improvement of corrosion fatigue strength of materials by various surface treatments

In this paper it is summarized on improvement of corrosion fatigue strength of materials by various kind of surface treatments mainly based upon the author's experimental data. It is described on the effect of synthetic resins, thermal-sprayed coatings and ion plating on corrosion fatigue strength of structural materials. The emphasis is focussed upon the tar epoxy resin coating for ship structural steels and thermal-sprayed coatings for machine structural steels. The mechanism of the improvement of corrosion fatigue strength of materials by surface coatings are also described. It can be concluded that the improvement of corrosion fatigue strength is not effective when an interception effect disappear due to the breakage or degradation of the tar epoxy resin coating. It can also be concluded that the effective thermal-sprayed coating to improve corrosion fatigue strength should be of very low porosity and firmly adhesive to die base metal.