Aluminium vs Hot dip galvanized steel in soil

[Micpage]

Hi,

I design a piece that will be placed in the soil. This piece can be installed in many type of different soils (from sand to clay soil).

If we don't want use any coating, does the aluminium (6063-t5) have a better corrosion resistance in soil than hot-dip galvanized steel?

Galvanic chart show that zinc will corrode before the aluminium. So, I think that hot-dip galvanized steel will corrode faster than aluminium. Am I truth?

Thank you

Michael Page
Engineer in calculus and simulations
IDÉA Innovation PME
(418) 695-4332

 

[KENAT]

The point of zinc is that it's a sacrificial coating, it corrodes instead of the steal.

If the zinc coating gets damaged or scratched in operations that reduces its performance.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[CoryPad]

Aluminium alloy parts can be direct buried into soil. They usually will have higher corrosion resistance than steel items that are placed into soil.

 

[strider6]

in my opinion is not possible to select a metal for every type of soil. depending on many factors the corrosion rate can change significantly for the same material.. the galvanic chart has nothing to do with the corrosion resistance in soil of a metal...

http://www.galvanizeit.org/images/uploads/drGalv/zinccorrosion_soil.pdf

http://www.corrosionsource.com/technicallibrary/corrdoctors/Modules/SoilCorrosion/Frames.htm

http://www.azom.com/details.asp?ArticleID=1280

S

Corrosion Prevention & Corrosion Control

 

[Micpage]

Thank you for all your answer.

So, if I understand correctly, I can't select a material only by theoric. I have to test them in soil and compare results.

Also, if you have any other informations on the subject (aluminium vs galvanized steel), add it on this post please.

Thank you,

Michael Page
Engineer in calculus and simulations
IDÉA Innovation PME
(418) 695-4332

 

[KENAT]

It's also the variability of the soil that's an issue. Things like moisture content, acidity/alkalinity, termperature, mechanically abbrasive nature (if driven in) etc. will all effect matters.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[stevenal]

In my industry, aluminum in the ground is a no no. Aluminum grounding conductors must transition to copper above the soil before being connected to galvanized ground rods below. If copper theft is a concern, galvanized steel armored copper can be substituted for pure copper.