The steel structure
The steel structure
To the steel structure, the speed of corrosion is mainly relate to the air relative humidity and the
composition and quantity of pollutant in the atmosphere.
In order to reduce metal corrosion and extend its service life, we must adopt the spreads brushes
and spray finishing methods after operate the surface treatment, to form the protective film in the
metal surface, and cause the metal and the corrosive medium isolates, thus prevents the metal the
corrosion.
国产真人作爱视频,国产精品国产自产拍高清AV,国产一区二区欧美激情,免费在线a级片