FUNDAMENTAL STUDY ON CORROSION RESISTANCE AND ANTI-CORROSION OF INTERFACE BETWEEN Al-5Mg THERMAL SPRAYED COATING AND HEAVY DUTY PAINT COATING

Abstract

 The objective of this research is to clarify the characteristics of corrosion resistance and anti-corrosion of interface between Al-5Mg thermal sprayed coating and heavy duty paint coating. Accelerated exposure tests were carried out on steel plates with the overlapping and butt layers with introduced linear or strip steel base-exposed portions. In addition, the AC impedance measurements, elemental analyses using EPMA, etc. were also conducted. Their results indicate that the deterioration of the overlapping layer at the steel base-exposed portion occurs earlier than that case of only Al-5Mg thermal sprayed coating. And then, the anti-corrosion performance would be lost after the thermal sprayed coating deteriorates and peels off from steel surface. The overlapping layer deteriorates in an earlier stage and then anti-corrosion performance is easier to decrease as the width of the steel base-exposed portion increases.