Welding Tips and Tricks

Hey so I have question for you guys. This week at work they changed a flange design and switched to a different casting company. But these new flanges do not act like 316 l at all, it acts a lot like
hastelloy. So after welding up a few I brought it up to a welding engineer at my work and told him that I believed these flanges had to much nickle in the casting cause of the way the weld wants to wash out and it takes about 40 less amps to weld to get the required 5 hmm cover weave and about the same less amps on the first two passes. He said he would take one to our metrology lab and have it tested. He did and came back and told me it was within the 316 l spec. What would cause these to act so much different than the previous castings?

316L, like any other alloy, meets a specification for content.

Each alloying metal has a specified "range". Two suppliers' 316 can be rather different in properties, while still meeting the definition.

That said, had you not had the metal lab-tested, I've encountered Chinese stuff so far out of range... Somewhere, I have a picture of a "304L" ell, hanging from my pickup magnet.

Steve S

OK that's what I was kinda thinking. It sucks cause the company is so big our cast stuff comes from like India, Thailand it was already crap guess things just got tougher. So my next question is this. How will this affect the penetration. I know common sense says 40 amps less will result in less pen or it is that new flange actually takes less heat to weld. I asked to send one to the testing lab, but they wont let me. Its only me and lead welder that weld these and he is busy training two new guys and he doesn't believe me.

This is speculation, of course, but,

If it behaves similar with the amperage change, your results should be similar as well.

Only time and testing will tell for sure.

It just makes me nervous because these are high pressure flanges up to 10 000 psi. I showed the engineer he said as long as I am meeting the weld specs I am fine but part of that is the pen. And it sucks because I have two more orders to do tomorrow. But the ones I did with my old setting were were way over the 5mm, almost 6.5mm.

I can show you welds in 304, for 8000 psi hydrogen service, that spent 10 years in use. These images would curl your hair. Some are pipes that were simply butted and crowned. Some attempted a root pass with no idea what they were doing, with bits of rod fuse inside the pipe.

None of this bullshit failed in ten years, to my complete amazement. You may be overthinking it.

I'll see if I can dig one of those photos up.

Steve S

Here's one. This is scary stuff.

Like staring at clouds, I see art in that.

I see a soldier wading through the surf, his gun held aloft, as a wave breaks over him...

The shop that did this work claims to have had 10% of the welds x-rayed, per contract. Oddly, they can't seem to find the records now.

Wow. That is terrible. This weld I am doing is not a open root pipe weld. It is a fillet. Its a 7 inch thick by 40 inch flange and then I weld in a 24 in hub to the flange. But that does make me feel better. I remember you posting that picture a while ago.

Just do it right, and let the engineers sweat the details... If your weld meets the spec, any issues are on QC or engineering.

(You should be absolved in the matter anyway. You did your due diligence by reporting the performance difference.)

Steve S

I will just run them like I did yesterday. Looks the same as previous flanges just a little less amps. I wanted to try to wait to do them to see if I could bug the lead Guy to try one but they are already behind cause of the design change and they take a long time. 24 inches of weld each pass and there is 35 waiting for me tomorrow.

That's a busy day.

With the new material, I'd watch for problems as you weld; I sometimes weld cast SS valves to piping, and once encountered a large casting inclusion at the weld zone.

Yep I hate sand pockets, can make a nice looking weld in scrap in no time LOL