涂层加速老化与自然曝晒试验的相关性分析

In order to study the correlation between accelerated aging test and natural exposure test, a comparative test between the exposure test and accelerated test on typical 7B04 T74 aluminum alloy-30CrMnSiA steel-7B04 T74 aluminum alloy connectors with double row 8 steel screws was carried out. The specimens were accelerated in the protective coating accelerated aging environment for 6 cycles and the natural exposure test of Wanning, Hainan for 2 years, respectively. The aging features including loss of gloss, fading, chalking, bubbling, cracking, flaking and metal substrate corrosion of protective coating were observed and measured, the aging characteristics and matrix corrosion products of accelerated aging and natural exposure protective coatings were compared and analyzed, the comparison on the tested aging characteristics of protective coatings indicates that the accelerated aging test can make the characteristics of the field aging reappear. Considering the multi-attribute and dynamic characteristics of aging characteristics of protective coatings, the aging damage in two environments is comprehensively evaluated quantitatively, and the variation law of aging characteristics with time is described by exponential function. By comparing the aging kinetics, the equation of the equivalent acceleration factor was given. The equivalent acceleration relation between two environments was obtained as 0. 4 year/cycle.