Standard No.:	GB/T 30789.4-2015
English Name:	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
Chinese Name:	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
Chinese Classification:	50
Professional Classification:	GB    National Standard
Issued by:	AQSIQ; SAC
Issued on:	2015-07-03
Implemented on:	2016-2-1
Status:	valid
Language:	English
File Format:	PDF
Word Count:	8500 words
Price(USD):	120.0
Delivery:	via email in 1~3 business day

本部分给出了通过与标准的图示比较，使用第1部分中规定的定义，来评定开裂等级的方法。
ISO 4628-1定义了关于涂层老化引起的缺陷的数量和大小以及外观均匀变化程度评定体系，并概述了评定体系的通则。该体系特别适用于人工加速老化和天然曝晒引起的缺陷和均匀变化，如颜色变化,例如：黄变。