Weathering steel connection

[DWPENGR]

I am designing a security fence made of 3/8” thick weathering steel panels (ASTM A588) attached in direct contact with hot dip galvanized (ASTM A123) columns (ASTM A36). The Architect does not want bolts to be visible from the front side of the panels so I was thinking of installing fully threaded 302HQ stainless steel Nelson studs to the back side of the panels for attachment to the columns. Is this an acceptable connection in terms of corrosion ?

 

[corrosionman]

I suspect you will receive many more replies advising against use of Stainless and galvanised steel for outside use . Dissimilar metal corrosion will very rapidly cause problems at the point of joining. Can you not use Galvanised bolts?
Cheers David W

 

[DWPENGR]

Thanks for the reply David.
The bolts I'm using here are stainless steel (not galvanized). The bolts are actually threaded studs welded to the weathering steel panels. Do you think the weathering steel should to be insulated from the galvanized steel columns?

 

[SMF1964]

The problem is the galvanic couple between the stainless and the weathering steel. I expect you'll see some galvanic corrosion at the weld HAZ in the weathering steel. If this connection is close enough (as in direct contact?) to the galvanizing, then you should get some protection due to the zinc.

 

[MikeDB]

The January 2004 issue of Modern Steel Construction had a "Steel Interchange" response by Keith Mueller on design considerations for weathering steel structures (ref.

http://www.aisc.org).

If I understood it correctly, stainless steel or weathering steel hardware is recommended for use with weathering steel. They advise against the use of galvanized hardware, but it has been done for years in the electric utility business.

Mike