410S to 516-70 carbon steel 2

[Sleegers]

I’m looking for some advise on welding 516-70 carbon steel to 410S stainless. I made some new PQR’s using 5/16 and 3/16 plate with .035-309L – HiSil hardwire, with our Lincoln STT for a open root. Then proceeded to cap it with 309L flux core. The bend test failed on the face side (It split on the 410 side and followed the edge of the weld zone to the root). I have tried capping it with 309L rod but had the same if not worse results.

If you have any advise/knowledge on this material that could help it would be greatly appreciated.

 

[metengr]

I would use Inco 182 filler metal versus 309 ss. Second, what was your preheat temperature? With the Ni-base filler and 450 deg F preheat, for this thickness you should be able to pass with no PWHT. Can you PWHT if necessary? Third, as an option, you can butter the 410S base material using Inco 182 filler metal, PWHT the 410S and then complete the remainder of the joint with Inco 182 to carbon steel.

 

[Sleegers]

Pre heat was 400F and interpass was kept below 500F. The vessel requires PWHT at 1150F (1hr min)

 

[weldstan]

Is the 410S a pressure part? If not is it welded directly to the pressure part? or a non-pressure part like a carbon steel tray support? Is it a fillet weld? In short, can the weld be exempt from PWHT? If PWHT must be done, see metengr.

 

[Sleegers]

First thank you for the quick resonds.

The 410S is no longer going through the pressure boundry (due to failing to pass impact testing) we have changed the design (repaced a rolled 410S plate that maked a 16" nozzle with a 16" SA 106-B pipe and weld overlay). There is a 410S 6" internal pipe(rolled plate with long seam, which is 410S to CS 6" pipe then going through the pressure boundry),header assembly and box with tray compartments that must be welded into place before hydro and PWHT.
I have been reserching this for some time now and have not herd anything about Inco 182?? Have you welded these dissimilar metals with this filler metal before??
We do not do the testing in house so it is getting very costly to keep testing with negative results

 

[metengr]

Yes, I have used Inco 82 and Inco 182 for many dissimilar metal welds;

http://www.specialmetalswelding.com/products/inconel/inconel.htm