日本免费在线观看视频-日本免费在线-日本免费一区二区在线观看-日本免费一区二区视频-2017国产小视频-2017能在线观看的网站

Corrosion prevention is the use of various methods to protect metal objects that are prone to rusting, in order to extend their service life. Generally, physical corrosion prevention, chemical corrosion prevention, electrochemical corrosion prevention, and other methods are used.

The anti-corrosion level is classified into the following five levels according to indoor and outdoor:

It can be seen that WF1 and F1 are respectively of the outdoor moderate corrosion protection type and the indoor moderate corrosion protection type. These two corrosion protection levels are applicable to different environmental conditions and are not comparable.
Service Hotline: 18924609560 (same WeChat account)