316-L weld ability to hastelloy c-276

[Aloni]

Hi to all

We are intending to manufacture hastelloy c-276 reactor with stainless steel 316-L half pipe jacket.
Design Condition in the c-276 vessel: -1+3 barg @ 200 Celsius
Design Condition in the 316-L half pipe jacket: +9 barg @ 200 Celsius
We know that the optimal way to weld the 316L to the c-276 is (ERNiCrMo-4) filler metal
But due to the media in the half pipe jacket "steam" and from economical point of view
Can we weld them with (ER316L) filler metal? And avoid cracks due to the hot & cold cycles

Thank you
Aloni

 

[pradipgoswami]

Hi Aloni,

If you're convinced that these dissimilar joints could be welded safely with C-276 (ERNiCrMo-4) filler,then stick to that.

The alternative i.e 316L filler will generate a weld with lower strength(even may be formation of eutectics)and welds could be prone to cracking, during welding or while being in service. That's why welding fillers with richer chemistry are always recomemnded for such dissimilar joints.

You may save one time but pay later for multiple time, through repairs and shut downs.

Thanks

Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist
Ontario, Canada.
ca.linkedin.com/pub/pradip-goswami/5/985/299

 

[XL83NL]

+1 on pradipgoswami. Consult e.g. API RP 582 for selecting optimal filler metal selection for dissimilar weld joint design, under 'standard' conditions.
Keep in mind that specific process requirements (medium, design temperature) may require other filler metal.
An example is using 309L for SS-CS joints, which is limited to 600 F (recognized also by e.g. VIII-1).

 

[Aloni]

Thanks to all

Aloni

 

[stanweld]

We had a case, not long ago, where the Engineer (and I use that term lightly) specified a similar weld to be made with an austenitic stainless steel filler metal. After repeated weld metal cracking, a change was finally made. It has long been recognized that such welds should be made with Nickel base welding filler metals. To do otherwise is to court disaster.

Similarly austenitic stainless steel can be welded together or to carbon steel with low hydrogen carbon steel filler metals/processes. But why would you ever want to do so?