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Up Topic Welding Industry / Technical Discussions / Need help with impact test on carbon steel
- - By JBOLDUC Date 08-29-2012 05:32
We are trying to qualify a PQR with impact at -20°C.   We need 27 J min. / 34 J average.

Base metal: SA-516-70  1.5" thick.
Filler metal: E71T-9M  1/16"  with 75%Ar-25%CO² (per AWS: 27 J @ -30°C / per data sheet: 56 J @ -30°C)
Position 1G.
Preheat 150°F.
Max. interpass: 315°F.
Max. heat input 35 Kj/in.
PWHT: 1125°F for 3 hours.

Results:  Pass the traction and bend tests without problem. Average impact: weld= 5 J / HAZ= 34 J / 516-70= 182 J

I don't think there is anything wrong with the procedure.

This is our second attempt. The first time we try with a different filler metal with similar result.

Any idea of what can be our problem?

Thanks for your help.
Parent - - By nantong (**) Date 08-29-2012 08:15
AWS values I believe are in the as welded condition. Your 56J on your data sheet does the certificate state tests done in the heat treated condition? If not then this a clear indication that the heat treatment of this rutile cored wire has degraded it's properties. Common problem.
Parent - - By 803056 (*****) Date 08-29-2012 11:40
I agree with Nantong. Your time at temperature appears to on the high side.

A change from one manufacturer and to a different (specific filler metal) tradename will produce different results. Many of the electrodes a classified under a couple of different classification depending on the specific shielding gas used. A change in shielding gas has an effect on the mechanical properties in both the as welded and PWHT conditions.

The heat input looks pretty low. Did the test samples pass the guided bend and reduced section tensile tests? Just curious whether or not there were fusion type defects present.

Best regards - Al
Parent - - By JBOLDUC Date 09-09-2012 16:01
Following your comments, we contacted our supplier and effectively, we did not have the right filler metal for PWHT.
We finally used a -12M filler metal reporting good impact result after PWHT and this time, we passed the impact test without problem.
Thanks very much for your help.
Parent - - By 803056 (*****) Date 09-09-2012 16:56
I am glad we were able to help.

Best regards - Al
Parent - By nantong (**) Date 09-11-2012 10:55
I am also glad "we" were able to help!
Up Topic Welding Industry / Technical Discussions / Need help with impact test on carbon steel

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