ステンレス鋼のさび発生挙動のキャラクタリゼーション

抄録

Through the analyses of sensory evaluation of model panels simulating rusted stainless steels, it became clear that perception of human being is affected not only area ratio of spots but also their size and numbers. Based on this result, the quantitative evaluation method to obtain the level of dirtiness was developed using the plot of the density of rusty dots against their area ratio, in which the average size of rust can be calculated from the slope of a straight line connecting each datum point and the origin. Furthermore, it was found that the points of the same aesthetic category are plotted in a zone limited by straight lines with slope of ca. -1. By this approach, three stages of weathering process of stainless steels are first characterized as follows; (1) nucleation of pits from which increase in the number of small spots ensue, (2) expansion of individual rusty dots, and (3) coalescence. Aesthetic degradation of the stainless steels is appreciable up to the stage (2), while not so noticeable when in the process (3).