welding of 304L ss pipe 1

[shajanps]

Experts,
Please advise me whether Er316L filler material shall be used for welding SS pipe of 304L type. Normal practice is to use 308L filler but now some joints are already welded with 316L.so now I am trying find the possibility to justify it through a new Wps which will use 316L filler. None of the electored manufactures manuals also recommending such usage...please share your knowledge in this subject.

 

[weldstan]

It depends on the service condition whether you should allow the 316L deposited filler metal to remain in place. In many cases it would not matter from a fitness for service standpoint.
I once audited a job where the opposite occured; that is, ER/E308L was used to weld all 316L materials on the project. Removal and replacement of the welds with 316L was required.

 

[shajanps]

Ofcourse 316 is a higher grade than 304. In that sense some people justifying such usage. But I can't find any recommendations of code or any electrode manufacturer for this.

 

[EdStainless]

The problem is that 316 can end up with more segregation.
What you need to do is check the residual ferrite levels in the welds.
Typically when welding with 308 or 309 there will be very little residual ferrite.
This ferrite is very easy to corrode in even mildly acidic environments.
That would be a place to start.

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Plymouth Tube

 

[OGMetEngr]

Like the previous posts state, it depends on what kind of exposure the material will be in. For example, hot concentrated nitric acid would preferentially corrode the 316L, all other things being equal.

 

[0707]

in my opinion 308 shall be used.

 

[OGMetEngr]

JB-weld or super-glue may be fine. It all depends on the service (temperature, stresses, environment, etc.)