Study Of Failure Rules And Residual Life Prediction Of Epoxy Acrylic Polyethylene Coating

With the development of economy, more and more serious environmental pollution lead to atmospheric environment deterioration, obviously this greatly accelerated the corrosion damage of steel structure and added the difficulty of corrosion control. Organic coating protection is one of the most effective and economic method to control the equipment corrosion, generally the epoxy zinc-rich base coating+epoxy mica iron oxide coating+acrylic acid polyurethane coating composite system was chosen as long-lasting protection system. However, the anticorrosion coating performance gradually decline and losing protection to the base material due to various influencing factors when coating exposed in the atmospheric environment. At present, there is a lot of reports about various factors affect the performance of anticorrosion coating in the domestic and foreign, many scholars has done much research on the epoxy acrylic coating anticorrosion coating failure mechanism and the factors affecting coating properties, but still can not provide valid coating failure data for coating repainting and maintenance, how to better describe the coating failure degree along with the time and residual life prediction has become an important research direction, and has important research significance.The epoxy acrylic polyethylene aging resistance and corrosion resistance change rule was studied according to the accelerated aging experiments and accelerate the salt fog test in this paper. Factors of coating failure was analyzed, the correlation of outdoor exposure test and artificial accelerated experiment was investigated. Based on the above analysis, life prediction model of epoxy propyl polyethylene coating was established, the concrete work was as follows:(1) The variations of gloss, gloss loss rate, and color difference of epoxy acrylic polyethylene coating with accelerated aging experimental time were investigated through xenon lamp indoor accelerated aging test combined with the detection of adhesion, pulverization degree and apparent morphology analysis, also the mathematical models between aging resistance indices and accelerated time were established preliminarily. The results showed that the mathematical models of the gloss and the gloss loss rate with the accelerated experimental time were similarly exponential functions, the mathematical model of the color difference with the accelerated experimental time was similarly power function. The experimental data were well fitted based on the mathematical models as to get the mathematical relationship, the correlation coefficients were above 0.99.(2) According to the electrochemical and surface detection results of template coating, the coating corrosion current rising rate, low frequency impedance decreasing rate and hole bubble area rate can be used as indicators to investigate the corrosion resistance of epoxy acrylic polyethylene composite coating, the change lows with accelerated experiment time of the three indicators was similar and accord with similarly exponential function. The experimental dates of coating corrosion current rising rate, low frequency impedance decreasing rate and hole bubble area rate with accelerated experiment time can be batter regression analysised, the correlation coefficients were above 0.99. The change lows can be better described by them and an effective method will be provided to evaluate the corrosion resistance and residual service life of composite coating.(3) Explored the measurable performance indicators characterized the failure degree of epoxy acrylic polyethylene composite coating in service, gloss, gloss loss rate, color difference and hole bubble area rate was chosen as measurable performance indicators to represent the coating failure degree and forecasting residual service life. Factors of coating failure and weight coefficient of each performance indicators in residual life prediction model was analyzed, the correlation of outdoor exposure test and artificial accelerated experiment was investigated. Based on the above analysis, life prediction model of epoxy propyl polyethylene coating was established and the mathematical model was applied in a instance.