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DON’T use 316 on 304!

cyanidekid

Titanium
Joined
Jun 4, 2016
Location
Brooklyn NYC
I have been doing a little research on the welding forums and the net in general and I am (very) slightly surprised that pretty much everyone is saying is ok, fine or even better to weld 304 with 316 rod for various reasons that range from misguided to compleatly insane.

Generally, the use of an “overmatched” filler ( a crapy description to begin with) is standard practice, but the one thing you almost NEVER want is a weld that has LES ductility than the material welded.

ER316L is NOT “better” just because it is a bigger number that ER308L!

316 is generally harder, more brittle, and more likely to crack than 304 or 308. It IS the right rod to use for, surprise! 316

308 is the filler for 304, and yes most of the time you can get away with using 316 just fine, but I think it is a lazy, poor practice to use it routinely and worse to say it’s fine, and plain stupid to say it’s better.

Well, what do you think? :D
 
Not disagreeing, as it seems you're more knowledgeable.
i do know that no discussion of 300 series and welding is complete with out mentioning 304L; the low carbon weldable variation.
 
The rod is pretty much ALL low carbon unless otherwise specd, so I left out the L, but probably shouldn’t have, so good lookin’ out.. i will edit the OP
 
Worth remembering both thoes fillers have a lower yeild than plane old ER70 filler, that every one and there welding monkeys use to join most std low carbon shit.

if you want it strong, best plans not to be using 316 or 308!!! Your advise is akin to picking nats shit out of a slury tank the diffrence in yeild bettwen the 2 is 1000psi and thats nothing worth thinking about in a unspected just gotta stay together kinda weld following no more procedural correctness than melt and slobber together. IMHO but yeah its Friday night and i may not be too sober.

Now if you want it to not corrode, theres something to be said for it still. Equally i have seen a lot of cracking when a new manager descided it would be a great idea to weld high grade 700 series weldox structures with a equally hard filler with no preheat and was kinda supposed it all cracked, despite the weld being stronger thankfully he got fired for it.

Now back to getting gerbils to mars plan, because im colinising the place with them, far cheaper to send than big fat americans and based on elons prices i should be able to have a successful colony numbering in the 10K of the cute little buggers before the 2 year resupply mission brings more sunflower seeds to get the population well over the million mark within the first decade, after watching the martian film too, all that gerbil shit should make for great potatoes when me as there ruler arrives so there will be plenty of chips and my usual healthy died need not suffer.
 
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Now back to getting gerbils to mars plan, because im colinising the place with them, far cheaper to send than big fat americans and based on elons prices i should be able to have a successful colony numbering in the 10K of the cute little buggers before the 2 year resupply mission brings more sunflower seeds to get the population well over the million mark within the first decade, after watching the martian film too, all that gerbil shit should make for great potatoes when me as there ruler arrives so there will be plenty of chips and my usual healthy died need not suffer.

I advise some lab work first. Raising a few generations of Gerbils on an ever-increasing atmosphere of CO2 and ever-decreasing percentages of oxygen should do the trick. If you can get them to survive with an O2 level down to around 0.2 or 0.3%, they will be fine after the trip.
 
I advise some lab work first. Raising a few generations of Gerbils on an ever-increasing atmosphere of CO2 and ever-decreasing percentages of oxygen should do the trick. If you can get them to survive with an O2 level down to around 0.2 or 0.3%, they will be fine after the trip.
I think Richard Gere showed that gerbils can survive a low oxygen environment. Maybe if Elon could get Gere to mars with a few gerbils they could start the colony, hehe "colon colony" :eek:
 
I advise some lab work first. Raising a few generations of Gerbils on an ever-increasing atmosphere of CO2 and ever-decreasing percentages of oxygen should do the trick. If you can get them to survive with an O2 level down to around 0.2 or 0.3%, they will be fine after the trip.

Why think about it, fat Americans weigh at least the same as 1000 gerbils, something the size of a 6 u cubsat could take the first breading half dozen of them to mars, trust me half a dozen gerbils bread and multiply faster than any imigrant's your current president has even dremt off. oxygen needs of a gerbil is tiny compared to fat Americans. Need to work it out but i recon a full size welding tank of oxy would probaly do em for several months with some CO2 scrubbing. The issue is just like on the martian film you need something to grow when you get there, instead of spuds which grow in the soil and get contaminated in that toxic dust on mars, im proposing sunflowers, can simply blow the toxic dust of the seeds and hay presto you can feed the little blighters. Can breath the oxygen made by the sunflower plants and you can harvest the methane from the tiny gerbil farts for the return journey fuel its all so easy with a life form as small and possibly expendable as a gerbil unlike cranky fat Americans. There not too stupid or smart either, there pretty easy to train, have no understanding of danger hence should make great potential astronaut material.

We are already flying mice on the ISS, why not gerbils to mars? Hell even spinning the space craft fast enough to create full martian gravity is easy, hell you could just re-purpose a washing machine drum with the holes welded up (308 or 316 filler anyone so i can't be accused of pulling this off topic???) Could see were there going through the glass door (yeah im thinking a European washing machine, so we can get ESA funding opportunities too.) Everything is so much easier and more doable with our current technology when the life form your proposing to colinise the planet with is a thousandth of the size of us big fat humans.
 
I think Richard Gere showed that gerbils can survive a low oxygen environment. Maybe if Elon could get Gere to mars with a few gerbils they could start the colony, hehe "colon colony" :eek:

RLOL :bawling::drink: I had to google that, i can say one thing, if a gerbil saw a hole, you can be certain they would go up it because any tunnel has to be explored, they will happily dig though when they get stuck! Socks are there biggest downfall, they kinda get lost in them and struggle to find the way out. Thankfully i doubt theres too many odd socks kicking around mars.
 
I have been doing a little research on the welding forums and the net in general and I am (very) slightly surprised that pretty much everyone is saying is ok, fine or even better to weld 304 with 316 rod for various reasons that range from misguided to compleatly insane.

Generally, the use of an “overmatched” filler ( a crapy description to begin with) is standard practice, but the one thing you almost NEVER want is a weld that has LES ductility than the material welded.

ER316L is NOT “better” just because it is a bigger number that ER308L!

316 is generally harder, more brittle, and more likely to crack than 304 or 308. It IS the right rod to use for, surprise! 316

308 is the filler for 304, and yes most of the time you can get away with using 316 just fine, but I think it is a lazy, poor practice to use it routinely and worse to say it’s fine, and plain stupid to say it’s better.

Well, what do you think? :D

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316 is more expensive. normally nobody uses 316 to weld 304.
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304 stainless is often Chinese 304 is what we call 347, if you use American 304 filler on 347 often the welds will rust. just saying using any 304 or 308 is often not the correct rod to use either.
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learned that one in China Chinese 304 or 308 filler rod ok with Chinese 304. or USA 304 or 308 ok with USA 304. just not a good ideal to mix it between stuff made in different countries
 
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316 is more expensive. normally nobody uses 316 to weld 304.
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304 stainless is often Chinese 304 is what we call 347, if you use American 304 filler on 347 often the welds will rust. just saying using any 304 or 308 is often not the correct rod to use either.
.
learned that one in China Chinese 304 or 308 filler rod ok with Chinese 304. or USA 304 or 308 ok with USA 304. just not a good ideal to mix it between stuff made in different countries

So the Chinese just give away the columbium and tantalum that makes it 347?:icon_bs:
 
So the Chinese just give away the columbium and tantalum that makes it 347?:icon_bs:

ok, coming back from mars...:), yup, have to agree with td there!

what DOES happen in a poor quality stainless, (wherever it is from, worst offender recently was some Indian 1/2 304 pipe from Mcmaster marked "Hindustan Inox", Terrible!), is that the melt includes all kinds of poorly sorted scrap. carbon steel, tool steel, aluminum, and they only adjust the melt to come out somewhere near 8 Ni, 18 Cr, and send it out.

if you weld on that, and the carbon is on the high side, you are prone to rust in the HAZ (heat affected zone) adjacent to the weld where it isn't actually mixed much, if at all, with the filler. at heat the carbon combines with the chrome, and leaves the chrome oxide layer depleted.

post weld passivation should return you to maximum rust resistance for that alloy, but I can't see how using "USA 308" filler could possibly compromise it.
 
I've heard of cases where they use 316 on 304, has to do with corrosion and the inability to re-heat treat the pipe/structure after welding. In some cases the %4 of moly in the 316 helps the weld not corrode.
I've also heard of 309 being used on 304 for similar reasons.
These problems are usually sorted out by the higher pay grades for a reason
Or you can do like on HVAC equipment place I heard about, they used hastealloy W on EVERYTHING, and most of it was plain old low carbon steel...
 
The use of 309 filler on 304 is generally fine, it is very close to the recommended 308, basically a 12-22 instead of a
10-20 Ni Cr and the ductility is comparable .
The potential problem with the 316 is the moly can make it less ductile, and subject to cracking in a cyclically loaded joint.
As stated above, most of the time, it is totally fine to use 316 on 304, BUT there is a reason 308 is the proper filler, and it is lazy not to think this through and just say “ oh it’s fine-easier- better”.
I admit to overstating the case a bit to get the discussion going, little did I know we were off to Mars! 😊
 
I have been doing a little research on the welding forums and the net in general and I am (very) slightly surprised that pretty much everyone is saying is ok, fine or even better to weld 304 with 316 rod for various reasons that range from misguided to compleatly insane.

Generally, the use of an “overmatched” filler ( a crapy description to begin with) is standard practice, but the one thing you almost NEVER want is a weld that has LES ductility than the material welded.

ER316L is NOT “better” just because it is a bigger number that ER308L!

316 is generally harder, more brittle, and more likely to crack than 304 or 308. It IS the right rod to use for, surprise! 316

308 is the filler for 304, and yes most of the time you can get away with using 316 just fine, but I think it is a lazy, poor practice to use it routinely and worse to say it’s fine, and plain stupid to say it’s better.

Well, what do you think? :D

You are correct, 316 is for 316… & 308 IS 304 unless you get a special batch (rich chemistry). At nominal 308 is middle chemistry 304 & at mean chemistry it is rich chemistry 304. The only times you pay more attention is “L” for low carbon or “H” for high carbon designation.

I’m shocked, SHOCKED I say, that there is questionable advice on the wild-wild web. Used to know a (very very good) welder that responded to “over-match recommendations” from people or salesmen with the comment “That’s for people who don’t know their trade”. LOL

Good luck,
Matt
 
^ Its also for people that have 5Kg of 1.6 filler in 316 and don't fancy buying a box of 308 because they don't generally weld up anything that matters in 304.
 
I was taught to go one grade up on filler... 308 for 304, 321 for 316 etc etc. That said if you are doing an actual critical weld then you should be following an actual procedure of some kind.
 
So the Chinese just give away the columbium and tantalum that makes it 347?:icon_bs:

working in China i sent metal analysis to my American Metallurgist. he is the one who explained often whats called 304 in China is not what we would call 304 in USA
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cross reference chart from Shiyong Wujin Shouce. most better machinist have that book in China. its common in book stores there
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dont care at all anybody's opinion on it. just stating a common experience working in China and buying metal there. quite easy for a extra fee get a metal analysis certificate with government stamp. cost extra but rarely forged as a person would go to jail for it. whats a extra 10 or 20% cost to know exactly what metal you are buying
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basically going to Chinese metal store with plate, angles, tubing its not like they have different types of metal unless its tool steel for die making. usually "304" used for outside handrail and window bars. quite common to hang clothes to dry outside window. bars to keep people from going through open window of course. many "condo" buildings have many welders nearby just making up window bars
 

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