Description
for the corrugated metal pipe, the outside is soil corrosion, the inside is water and air corrosion
about soil corrosion, in my country, most of them is middle corrosion.
air corrosion( ocea, industry, city, village）
abrasion
non abrasion (level 1) no gravel and other moving material, all speed or rainwater pipe
low abrasion (level 2）with sand and gravel, speed lower than 1.6m/s
middle abrasion (level 3) with sand and gravel, speed 1.6~5.0m/s
harsh abrasion (level 4） harsh gravel or rock, speed faster than 5.0m/s
metal structure corrosion in fluid (water, seawater)
