To investigate the corrosion resistance of overlapping layers between Al-5Mg thermal spray coating and heavy-duty coating, this study aims to clarify the deterioration behaviours of the cases with different boundary connection modes. The linear and ribbon defects were introduced to specimens, and the accelerated corrosion tests were performed. Besides, a laser focus measuring system was used to determine the blister condition of deteriorated coatings quantitatively. Test results show that the overlapping layer deteriorated earlier than the case of a single layer of Al-5Mg thermal sprayed coating, due to the sealing treatment. The corrosion resistance of the overlapping layer would be lost after the bottom thermal sprayed coating deteriorates. Thus, the sealing treatment of thermal spray coating would increase the consumption range of sacrificial anode material. Moreover, as the width of
the steel base-exposed portion increases, the overlapping layer deteriorates at higher rates causing it to lose its anti-corrosion performances faster. Test results were verified through the detection of the chloride near the blister area by conducting the Electron Probe Micro Analyzer (EPMA).
Muye Yang (Department of Civil Engineering, Kyushu University)
Muye Yang is a research assistant professor who has been working at the Department of Civil Engineering, Kyushu University since 2017. Her major field of study is steel structures, responsible for the maintenance of steel infrastructure. Participated relating topics are including the fatigue strength of weld joint, corrosion mechanism and cathodic protection of carbon steel, environmental deterioration of CFRP, development of electrochemistry sensor, etc.