GB/T 30789.4-2015
色漆和清漆 涂层老化的评价 缺陷的数量和大小以及外观均匀变化程度的标识 第4部分:开裂等级的评定
Paints and varnishes.Evaluation of degradation of coatings.Designation of quantity and size of defects,and of intensity of uniform changes in appearance.Part 4:Assessment of degree of cracking
GBT30789.4-2015, GB30789.4-2015