Corrosion effects on structural steel exposed to water

[lanejoe10]

I have an application where I am using HSS to frame a cofferdam. The dam should only be in the river about 6-12months. The steel will not have any protective coating.

Do I need to take into account the reduction in strength due to the steel corroding? Or is the corrosion insignificant due to the short period of time it is being exposed to the water?

Any direction on resources or information would be appreciated

 

[cloa]

Nowhere near enough detail. Need to know if the steel is totally submerged. Water oxygen content, temperature, salinity and velocity.

 

[TVP]

In general, I would say that 6-12 months in freshwater is not enough time to cause a significant reduction in strength, but if I were "engineering" such a system, I would be investigating/confirming the details that cloa mentioned...

 

[strider6]

from literature data the corrosion rate of carbon steel exposed to seawater is approx 0.5 mm/y in the splash zone and approx 0.2-0.3 mm/y in the submerged area.

http://www.seashield.com/nace2002.pdf

in freshwater the corrosion is approx the same.

hope this help

S

Corrosion & Rust Prevention Control

 

[lanejoe10]

thanks for the responses, this helps!

 

[photoengineer]

Yes, the steel should be oversized to account for the corrosion.

Cedar Bluff Engineering

http://cedarbluffengineering.webs.com