最新版的ISO 20340标准

zhanhongtu

现在正在研究Norsok M501,里面的测试就是引用的此标准，和之前的版本比起来还是有不少改动的。

zhanhongtu

现在是2009版的了， 样板尺寸，评价标准都有了一些变化！

Michael

具体说说最大的变化

zhanhongtu

样板尺寸变成了150*75mm，这就和Norsok M501的要求统一了，阴极剥离实验推荐使用ISO15711-2003版中的方法A也就是外加电流来做，还有附着力的评判标准，划线处腐蚀也对富锌底漆和其他底漆分别作了规定。

zblhx84

在ISO 20340-2009中，关于经阴极剥离试验后结果的评价，有以下描述：
Cathodic disbonding in accordance with ISO 15711:2003, method A
Immediately before the qualification test, form an artificial holiday (steel substrate totally exposed) of diameter 6 mm, using the procedure specified in method A of ISO 15711:2003.
After the qualification test, use a sharp, thin-bladed knife to make two radial cuts at 45° to each other through the coating, intersecting at the centre of the holiday. Cut the coating down to the steel substrate. Attempt to lift the coating with the point of the knife. Record the total area now exposed (including the area of the holiday). Calculate the disbonded area as the difference between the total area exposed and the area of the holiday.
From the disbonded area, calculate the corresponding equivalent diameter.
The equivalent diameter of the disbonded area shall be not more than 20 mm.

这里面提到，记录全部剥离面积（area），包括人工孔面漆。计算整个剥离面积和人工孔面漆的差异；然后计算相当的等效直径（ the corresponding equivalent diame）。剥离面积的等效直径不应超过20 mm。

想问一下，这个相当的等效直径应该如何计算呢？

sjy328199856

ISO 20340-2009Paints and varnishes -- Performance requirements for protective paint systems for offshore and related structures

csic725

zblhx84 发表于 2011-1-15 15:15
在ISO 20340-2009中，关于经阴极剥离试验后结果的评价，有以下描述：
Cathodic disbonding in accordance  ...

假如总的剥离面积为A,减去人造孔面积B（9π），，则剥离面积为A-B，按这个面积换算成圆的直径即是等效直径。