copper backing

By gsi

Date 11-08-2004 20:26

I have 316L base metal. We are running a 75 degree included v-groove with a 3/32 land and 1/8 root. Some of the welders are have been have trouble with excessive melt-thru and incomplete fusion. We did some training to correct the problem. The results have been good but the problem is still there. I had some 1/4 copper machined to the root contour I needed and started using this in production. The problem has gone away. Is the copper detrimental to the weld?

By RonG

Date 11-08-2004 21:10

Not unless you dilute it in to your weld.

By G.S.Crisi (****)

Date 11-09-2004 14:06

If you're using 316L stainless steel, chances are (good chances, by the way) that the reason is corrosive service. In this case, copper won't be detrimental to the weld, as Ron says, but it may be detrimental to corrosion resistance.
I'd recommend you to check it out.
Giovanni S. Crisi
Sao Paulo - Brazil

By rhoople47 (**)

Date 11-09-2004 20:14

GSI,

Have you tried to back purge the weld with Argon?

By gsi

Date 11-09-2004 20:56

Thanks for the input. Purging is not an option due to configuration of weldment. Corrosion is not an issue on the interior welds.