A36 to A36 using 309L 1

[rfitts]

I need to weld 1/2" a36 to 1/2" a36 which will eventually be overlayed one side with hard face. The customers spec is tig root pass with 309l and fill and cap with 309l. Why this process....should the weld be purged? Any help with generating a WPS? Bob

 

[unclesyd]

There is nothing wrong with welding CS/CS with SS except expense.
All SS welding has to be be shielded in some manner.

Comeback with more information a the the shape/form of the A36 to be welded and the process you intend to use.

What code or standard are you fabricating this component under?

 

[rfitts]

The A36 is 10" pipe, eventaully having the id hardfaced. I dont see any prior purging of the interior of the pipe required in the past. I am working with a new fabricator...just welded up his test coupon..be it a pipe coupon...gtaw process for the root pass 309L...smaw process using flux cored sticks 309L for the fill and cap...no purge...he was not impressed with the visual aspects of the coupon but sent it out for evaluation anyways....he mentioned the possiblity of purging the pipe..lot of purge gas. This is code welding. Bob

 

[unclesyd]

You are going to have to purge the root pass and keep the purge on during the hot pass. If you don't purge you will get "sugar" which will give problems with the subsequent hardfacing.

Which code are you working under?

 

[rfitts]

B31.3

 

[unclesyd]

The only A36 pipe I've seen has been very large.
This is P1 material so there is no problem with welding.

Do you have a P8/P8 WPS?
This should cover you as long as the welder has qualified on this procedure.

If not use 1/2" wall P1 pipe in the 6G position welded with 309 SS for the test and the WPS. This is with purge and either a bend test or radiography.

We qualify all welders for welding P8 materials by welding P1 pipe to P1 pipe with 309 SS filler.

Hopefully someone more verse in the latest on Section 9 will jump in here and straighten me out.

 

[metengr]

Do you have a P8/P8 WPS?
This should cover you as long as the welder has qualified on this procedure.

The WPS should be qualified for P-No 1 to P-No 8 base materials.

 

[rfitts]

why not use 309L for root pass and fill and cap with cs filler?

 

[metengr]

This would not work. Welding carbon steel filler metal over 309 will result in significant dilution problems that will result in increased susceptibility to cracks. It either has to be all 309 filler metal or carbon steel filler metal.

 

[stanweld]

I don't quite understand the Customer's requirements if hard facing is done after welding. If ID hard facing is done prior to butt welding, I fully understand and agree with the requirements assuming that hard facing is done with 410 type martensitic stainless or with other materials compatible with E/ER309L.

 

[QC1971]

Do you have a PQR to support P1-P1 with this electrode? If so it will be your guide for the WPS. If not you will need to do the procedure qualification on P1 materials using electrode with the same A-number and F-number to be used in production.

 

[Jon22]

This is a common test for certifing welders in stainless, it save $ on SS pipe coupons. You do have to purge. Why not weld it up with 7018 the pipe is A36 and the ID gets overlay. This process is a lot easier with more control and less chance of inclusions. If your doing it on rollers its 1G so thats not to hard. We overlay A36 with all types of Alloy to save on matierial cost.