I am a self-learning hobby welder. In between practice beads, I weld bits of scrap together and make junk.
IMG_20170305_112130_028.jpg (86.8 KiB) Viewed 1677 times
I was trying to weld a section of nail to a piece of hrs using er70s2. It started hissing and spitting and would not join. I don't know what the nail is made of but the other end welded fine. Both pieces were ground and wiped with acetone.
In a cant-hurt-to-try moment, I pick up a stub of 309L. It wet right in and lifted some crud out. I remember seeing or reading somewhere that 309L could be used for dirty situations but I am not sure. This is the internet.
I understand my use is not a critical application and anything that works would be fine. However is this a useable option if a similar problem is encountered on a more serious project?
I would have taken a picture of the horrible weld I am referencing but it is a nail welded to a piece of bar stock.
5th Street Fab wrote:I use it anytime I'm not sure of the metals I'm joining especially when ones stainless
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+1 on this. Even in more critical applications, I will TIG in a 309 root if the metal's old and dirty to resist the porosity, then, since it's buttered with clean metal, I'll cap it with 70-S2.
I cant find any info to back this up, but I was told not to weld over an ss weld (309) with mild steel as it will form hard martensite. This was stated in a repair situation where some f fool muggugit used 309 where it was supposed to be mild, removed the ss and went to reweld with mild again. This goes against what steve has said. I don't know what to think anymore.
One would think, then, that the weld test of 309 on carbon steel would find that issue of hard martensite in the HAZ, yet it's a common test, and a common weld in boiler tubes. I've never had an issue of any kind using this practice, and my welds are tested in numerous ways.
Mick, if you do find solid references for this, please share them here, as I certainly need to know if I've been doing something wrong in such a critical application.
Absolutely. I can ask my inspector tomorrow. I'm well versed in 309 on to mild and alloy steel, as I do it regularly. However I need to translate this idea i have in my head.
My father in law is a machinist and he said he has seen 309 used on socket welds for the oil systems on machines for this reason. He says its the best way to get a good seal.
Heres some good info, but I will definitely track it down from my end.
Mick
Interesting analysis! Seems, in the last post, the FN dilution from "overcooking" is the root cause for failure. I suppose I've never had issues because in the cases where I use 309 on carbon steel, the situation requires I keep the total heat input quite low. I'm also curious what effect capping a 309 root with 70s-2 has on this dilution.
I had a rushed conversation with my Welding Inspector this afternoon (right on knock off, hence the rush)
His theory is if you start with stainless, finish with stainless (to aid austenectic structure) To this rule, I have had to excavate s/s tack welds from under a steel weld, (you can see a crappy looking slag form on top of the weld) and complete a weld that is suposed to be carbon steel wire with stainless because it was tacked wrong. The dilution between the ss root and mild steel cap will cause Martensite to form and that is really hard and brittle.
I'd say this can be confirmed through a macro etch and hardness survey of the weld. Or a simple bend test, comparing two samples.
He did say it may come down to the use of the joint, as in cyclic load or vibration as to whether this becomes a major crack issue.
weldin mike 27 wrote:I had a rushed conversation with my Welding Inspector this afternoon (right on knock off, hence the rush)
His theory is if you start with stainless, finish with stainless (to aid austenectic structure) To this rule, I have had to excavate s/s tack welds from under a steel weld, (you can see a crappy looking slag form on top of the weld) and complete a weld that is suposed to be carbon steel wire with stainless because it was tacked wrong. The dilution between the ss root and mild steel cap will cause Martensite to form and that is really hard and brittle.
I'd say this can be confirmed through a macro etch and hardness survey of the weld. Or a simple bend test, comparing two samples.
He did say it may come down to the use of the joint, as in cyclic load or vibration as to whether this becomes a major crack issue.
Great Info!
I weld stainless, stainless and more stainless...Food Industry, sanitary process piping, vessels, whatever is needed, I like to make stuff.
ASME IX, AWS 17.1, D1.1
Instagram #RNHFAB
Again, I find this very interesting. My application is not usually exposed to stresses; It's to create a helium-tight seal on shitty metal. Sometimes, however, a stress-bearing working doubler is installed on top of one of these, in which case the sizes are stepped. If the working doubler is, say, 2 X 6 inches, then the live doubler will be 4 X 8 inches, to distribute the stresses over a broad area.
I'm going to have to dig a little deeper, I suppose. I've been using this technique many years and never had one return for failure.
Otto Nobedder wrote:Again, I find this very interesting. My application is not usually exposed to stresses; It's to create a helium-tight seal on shitty metal. Sometimes, however, a stress-bearing working doubler is installed on top of one of these, in which case the sizes are stepped. If the working doubler is, say, 2 X 6 inches, then the live doubler will be 4 X 8 inches, to distribute the stresses over a broad area.
I'm going to have to dig a little deeper, I suppose. I've been using this technique many years and never had one return for failure.
Steve S
What? I swore you welded on pressure vessels. Or maybe I overexxagerated what was said and you just weld holes to prevent leaking on low pressure vessels.
A student now but really want to weld everyday. Want to learn everything about everything. Want to become a knower of all and master of none.
Instagram: @farmwelding
Nick
Farmwelding wrote:
What? I swore you welded on pressure vessels. Or maybe I overexxagerated what was said and you just weld holes to prevent leaking on low pressure vessels.
I do both, and more.
The welding in question here is for a vacuum-jacket. An outer vessel of a two-part vessel, not unlike an old glass Thermos bottle. Everything on the inside is code pressure welds. Everything on the outside is non-code, as it only sees pressure from the atmosphere pushing in. The second group is where my use of 309 is targeted.
The code work has stringent policies about everything from how you prep the joint to documenting the source and analysis of your filler rod, which must be kept separate from general-use filler rod of the same designation. It gets complicated at times.
The welding in question here is for a vacuum-jacket. An outer vessel of a two-part vessel, not unlike an old glass Thermos bottle. Everything on the inside is code pressure welds. Everything on the outside is non-code, as it only sees pressure from the atmosphere pushing in. The second group is where my use of 309 is targeted.
The code work has stringent policies about everything from how you prep the joint to documenting the source and analysis of your filler rod, which must be kept separate from general-use filler rod of the same designation. It gets complicated at times.
Steve S
Farmer more than likely you will end up welding on more advanced things than you think your going to. You will see from a lot of others here that we tend to have two sides one side that adhears to the smallest details of a given code because that's what we are working on that day. And that's what's required by insurance and engineers. The other side of us is willing to experiment and over lap skills and tricks we have picked up along the way, when we aren't required to abide by a code other than our own personal rules it tuns into a I'll try to do that or a get it done, that's good enough mode. But it takes a lot of real world experience seeing how others work on things or how thing were put togeather the first time before it was broke.
True. When I began, I wasn't going to be a welder, I just needed to weld something, so I figured it out. When I took my first welding job, I never imagined where I'd be now. I have 30 years' experience behind me, and, Lord willing, 30 more to come. This gives me a perspective on what is good and what is "good enough". I've seen things that would make a novice welder cringe.
Sometimes it's to the rulebook, and sometimes it's use of experience.
Honestly, I don't have 30 years' experience, I have experience over 30 years. I've done other things, many other things, but always came back to welding. In my present job, I'm responsible for the most critical welds, but I don't weld every day. Sometimes I don't weld for weeks, and then I have to deliver a code weld or twelve that passes x-ray. No pressure...
I must admit, my employer is very understanding. If I say I want a practice coupon or three before I do the code weld, I'm allowed the time.
Otto Nobedder wrote:True. When I began, I wasn't going to be a welder, I just needed to weld something, so I figured it out. When I took my first welding job, I never imagined where I'd be now. I have 30 years' experience behind me, and, Lord willing, 30 more to come. This gives me a perspective on what is good and what is "good enough". I've seen things that would make a novice welder cringe.
Sometimes it's to the rulebook, and sometimes it's use of experience.
Honestly, I don't have 30 years' experience, I have experience over 30 years. I've done other things, many other things, but always came back to welding. In my present job, I'm responsible for the most critical welds, but I don't weld every day. Sometimes I don't weld for weeks, and then I have to deliver a code weld or twelve that passes x-ray. No pressure...
I must admit, my employer is very understanding. If I say I want a practice coupon or three before I do the code weld, I'm allowed the time.
Steve S
You should listen to the podcast with him of you hadn't. It's a good story.
A student now but really want to weld everyday. Want to learn everything about everything. Want to become a knower of all and master of none.
Instagram: @farmwelding
Nick
Thanks! It might have been better if I weren't half-lit at the end. I had no idea it would be over three hours to edit it to what was used. Another lesson learned. If I'm ever asked back, I will keep that in mind!
JHenze646 wrote:I am a self-learning hobby welder. In between practice beads, I weld bits of scrap together and make junk.
IMG_20170305_112130_028.jpg
I was trying to weld a section of nail to a piece of hrs using er70s2. It started hissing and spitting and would not join. I don't know what the nail is made of but the other end welded fine. Both pieces were ground and wiped with acetone.
In a cant-hurt-to-try moment, I pick up a stub of 309L. It wet right in and lifted some crud out. I remember seeing or reading somewhere that 309L could be used for dirty situations but I am not sure. This is the internet.
I understand my use is not a critical application and anything that works would be fine. However is this a useable option if a similar problem is encountered on a more serious project?
I would have taken a picture of the horrible weld I am referencing but it is a nail welded to a piece of bar stock.
