Welding Stainless Steel 316- Quenching or Not?

Some time back I heard that SS welding should be quenched. I vaguely remember is to avoid precipitation of atoms or some thing of the like.
I did a search on the net and found little about it and some confusing info too.
Does anyone here know of it please?

 

You can do whatever you like, with, anything you like.

But, in doing this, what is your objective...?...what do you have to gain or achieve...since your question is far too vague.

 

I'm not a pro steel worker, just want to do it right when I have to weld SS. My question implies, as you say, is there anything to gain or achieve in quenching SS? Thanks

 

But doing "something" has an objective...what is yours.

Since to quench or not to quench....everyone has a reason why they wish to do it. It might simply be because the fabby doesn't like hot steel about the place, each reason, in design, is different for everyone and needs to be addressed as to WHY....
Thus, you have not stated your reason why.

 

I am not a coded welder but have done loads of TIG welding of 304 and 316, never quenched just buffed the heat affected zone (HAZ) to look nice. Other processes might put more heat into the weld; might make a difference.
effects of welding on stainless steel https://app.aws.org/forum/topic_show.pl?tid=2024

 

Thank you Alan, your post lead to learn that there are a number of issues when welding these materials.
Here is about Sigma Phase Embrittlement of Stainless Steel in FCC Service - OnePetro https://www.onepetro.org/conference-paper/NACE-06578
Here more in depth about
Intergranular corrosion - Wikipedia https://en.wikipedia.org/wiki/Intergranular_corrosion
It mentions precipitation of chromium carbide at the grain boundaries.
From the article: "...
quenching it in water, leading to dissolution of the chromium carbide in the grains and then preventing its precipitation..."

 

Interesting articles. But also welds solidify then shrink due to cooling putting stresses into the material; quenching could make this worse. Lots to read up about, or you could just ignore it all and practice until your welds look nice!

 

I had a welding splitting like a piece of glass as soon as the rod was lifted.
It was a "fat" weld between two 1" DIA bars side by side.
I wonder if the great shrinkage due to accumulation of heat was the cause.
If that's the case, to avoid such a shrinkage ratio, would be to do one short weld and cool then another short weld and so on.

 

It primarily depends on what material it was. Cast iron (and also some high tensile steel) will crack when cooling down, is very hard to weld because shrinking when cooling, creates tension beyond breaking strain. Regular 316 stainless is very tough, will deform instead. I have never seen 316, welded with proper rod, crack after welding, even on thick pieces.

 

I can confirm never seen 304 or 316 crack after welding, but if you weld a tee with (for example) 304 1" square tube, the tube forming the top of the tee will bend towards the weld, so huge residual stresses in a very tough material.

 

3rd gen fabricator/ AWS cert inspector here. Joined just to answer this conundrum.
Anytime you quench a weld and the base materials, you are adding stress to the weld and the blended base material surrounding the weld. The weld itself will always have a different contraction rate compared to the base material. So quenching any weld and especially brittle metals such as stainless will create stress fractures on the molecular level, and leave you with a product that is not as strong as it could have been. If you ar wanting to create a stronger product, then encapsulate it in sand post weld and slowly bring the temp down evenly rather than shock it.

 

Can you explain the sand encapsulating?

Are you setting the item in sand and covering it with sand?

I am assuming the sand is bone dry as well? Otherwise, quench effect?

Thanks.

 

Cover it 100% with sand. Depending on how big your part is, that can be done in a bucket, barrell, or for large pieces... in a hole but then a backhoe is needed. The sand acts as an insulator and retains the heat so The whole product gets heated and cools equally therefore relieving stress. You are basically giving the product a low tempering.