彩涂板腐蚀分类及预防措施

腐蚀是三种形式中最复杂、最具破坏性的一种。由于彩涂板的腐蚀发生在金属与环境（介质）的界面上，并产生化学或电化学反应，因此研究金属的防腐是彩涂板的主要形式。其它材料抗腐蚀研究中比较困难的问题之一。金属材料的腐蚀分类通常包括以下几类：

（1）根据腐蚀环境：干腐蚀和湿腐蚀

（2）根据腐蚀机理：化学腐蚀、电化学腐蚀和物理腐蚀。

（3）根据腐蚀形式、点蚀和应力腐蚀开裂的类型

（4）按材料分的金属：“金属手册”中常见和实用的金属

（5）按适用范围：实际上是根据腐蚀环境分类的特殊应用。

金属防腐蚀的现象主要是上述第（1）点和第（2）点。点（1）处的干腐蚀属于化学机理，而湿腐蚀属于电化学机理。第（3）至（5）点属于第（1）和（2）点的进一步分类。 彩涂板的防腐机理是利用涂层将基体与腐蚀介质隔离开来，防止基体表面发生化学或电化学反应。因此，我们要研究的最终防腐问题应归因于涂层钢板表面的化学腐蚀和电化学腐蚀。

基于上述金属腐蚀机理，人们一直在寻找有效的控制金属腐蚀的方法。经过长期实践，基本形成了以下几种误用：

（1）选择金属材料时，尽量选择耐大气腐蚀的材料。

（2）表面保护涂层

（3）改变成分，加入缓蚀剂，抑制腐蚀过程。

（4）包装前进行防锈处理，贮存时保持干燥、清洁。

（5）在结构设计中，尽量避免裂缝、沟槽等易积水和引起腐蚀应力断裂的地方。

Corrosion is the most complex and destructive one of the three forms. Because the corrosion of color coated plate occurs at the interface between metal and environment (medium) and produces chemical or electrochemical reaction, the study of metal corrosion protection is its main form. One of the more difficult problems in the study of anti-corrosion of other materials. Corrosion classification of metal materials usually includes the following categories:

(1) According to the corrosive environment: dry corrosion and wet corrosion

(2) According to corrosion mechanism: chemical corrosion, electrochemical corrosion and physical corrosion

(3) According to the types of corrosion forms, pitting corrosion and stress corrosion cracking

(4) Metals according to material: Common and practical metals in "Metal Manual"

(5) According to the scope of application: in fact, it is a special application classified according to the corrosive environment.

The phenomena of metal anticorrosion are mainly points (1) and (2) mentioned above. Dry corrosion at point (1) belongs to chemical mechanism while wet corrosion belongs to electrochemical mechanism. Points (3) to (5) belong to the further classification of points (1) and (2). The anticorrosion mechanism of color coated steel sheet is to isolate the substrate from the corrosive medium by using the coating to prevent the chemical or electrochemical reaction on the surface of the substrate. Therefore, the ultimate anti-corrosion problem we want to study should be attributed to the chemical and electrochemical corrosion on the surface of the coated steel plate substrate.

Based on the above-mentioned mechanism of metal corrosion, people have been looking for effective methods to control metal corrosion. After long-term practice, the following kinds of misapplication are basically formed:

(1) When choosing metal materials, choose atmospheric corrosion resistance as far as possible.

(2) Surface protective coating

(3) Change the composition and add corrosion inhibitor to inhibit the corrosion process.

(4) Anti-rust treatment before packing and keeping dry and clean during storage

(5) In structural design, try to avoid cracks, grooves and other places which are easy to accumulate water and cause corrosion stress fracture.