彩钢板涂层加速老化与自然曝晒试验的当量加速关系研究

Study on the equivalent relationship between accelerated aging test and natural exposure test for color steel plate coating

为研究彩钢板建筑涂层加速老化试验与自然暴晒试验的当量加速关系,以兰州地区为例,对镀锌钢板表面涂红、白、蓝3种颜色烤漆的试件进行了5个周期的加速老化试验和户外5个季度的自然曝晒试验。研究分析了3种颜色样板不同加速周期和曝晒时间的防护涂层失光、变色、粉化、起泡等老化现象,并基于失光率的失效标准,对加速老化和自然曝晒的彩钢板建筑表面涂层老化行为进行分析。研究表明,加速老化试验可以再现自然老化特征。考虑到涂层老化特征的多属性和动态性,针对不同颜色涂层采用多种拟合方法对两组实验数据进行拟合分析,选用3种拟合方法并结合相关函数描述失光率及老化特征量随时间的变化规律,构建出3种颜色样板涂层当量加速关系的表示形式,并得到加速老化试验环境谱与户外自然曝晒试验的当量加速关系为:红色样板0.80季度/周期,白色样板1.03季度/周期,蓝色样板0.93季度/周期。

In order to study the equivalent relationship between the accelerated aging test and natural exposure test of the coatings on color steel plates for buildings,five cycles of accelerated aging test and five quarters of natural exposure test of zinc-coated steel plate with red,white,and blue coatings commonly used in Lanzhou City were carried out.The aging phenomena such as loss of luster,discoloration,chalking,and blistering appearing on the protective coatings of three colors at different acceleration cycles and exposure time were analyzed.The aging behaviors of the coatings on colored steel plates for buildings were analyzed based on the failure criteria of luster loss after accelerated aging test and natural exposure test.The results showed that accelerated aging test could reproduce the natural aging characteristics.Considering the multi-attributes and dynamic characteristics of aging of coating,a variety of fitting methods were used to analyze the data of the two tests for different color coatings.Three fitting methods were selected and the variation rules of the luster loss and aging characteristics with time were described with the correlation functions.The representation of equivalent acceleration relationship for the coating of each color was established.The equivalent relationship between accelerated aging test result and the natural outdoor exposure test result was determined as follows:0.80 quarter/cycle for the red sample,1.03 quarters/cycle for the white sample,and 0.93 quarter/cycle for the blue sample.