ASTM G48A 316L to SAF2507 weld test

[stanier]

In welds of dissimilar metals as above, what criteria is recommended for an ASTM G48 method A corrosion test. What acceptance criteria would you specify?

Geoffrey D Stone FIMechE C.Eng;FIEAust CP Eng

http://www.waterhammer.bigblog.com.au

 

[SJones]

Corrosion resistance can't be an issue otherwise why incorporate a lower grade material into the system. Therefore, is there much point in undertaking a ferric chloride test? One could simply rely upon good quality assurance of the whole welding process, a welding procedure with some 'pedigree', and normal destructive testing including micrography.

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/

 

[stanier]

That was my initial thought. However when considering that there could be 316l supports welded externally to the SAf 2507 is it not of interest to make sure that the welding procedure is not injurious to the SAF 2507?

Geoffrey D Stone FIMechE C.Eng;FIEAust CP Eng

http://www.waterhammer.bigblog.com.au

 

[SJones]

Yes - by normal destructive testing and micrography!

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/

 

[EdStainless]

Well if you are worried about backside issues with the 316 not wetted then go ahead. Weld a 316 piece to the back and coat the 316 and weld with good epoxy paint. Then you can test the 2507 as normal.
I would not use G48 A or B, use one of the newer methods with the acidified solution. They are more repeatable.
It might be even easier to use an electrochemical test for this. You can control the face exposure that way.

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[stanier]

edstainless,

Is there a standard that covers the electrochemical test?

Geoffrey D Stone FIMechE C.Eng;FIEAust CP Eng

http://www.waterhammer.bigblog.com.au

 

[weldtek]

It's pretty common to see a pad of matching material welded to the higher alloy and the lower alloy attached to the pad. In some cases a simple fillet weld test will suffice for the dissimilar weld, assuming of course you don't require a groove weld.

 

[EdStainless]

There are a number of proprietary ones, you can look in the Outokumpu lit to see what tests they have used.
There is a ASTM for it, G150.
I can put you in touch with someone that does this work.

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Rust never sleeps
Neither should your protection

http://www.trent-tube.com/contact/Tech_Assist.cfm