Cookpot destroyed by….???

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drummer4468

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drummer4468
Metallurgists and engineers among us, I have a question/puzzle for you.

So I have this cheap stainless pot in a camping cook set. It’s a cheap set from Wallyworld so that probably has something to do with it.

I used it for a few boil tests when test driving a new (white gas) backpacking stove I got. Cleaned it up and put it away for a few months in my unheated garage.

Just unpacked it for an upcoming outing and find this(below). Severe discoloration and vertical cracking all the way around. Most confusing is that the surfaces are all concave between the cracks, as if it were crushed evenly under water pressure or something. All of the pots nested inside are untouched, shiny and new.

Any idea what may have caused this? Do I chalk it up to cheap Chinese metal in a no-name cook set?

2AB12DC3-578A-4C20-8200-3325BB3C841D.jpeg
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Any chance of exposure to bleach? Chlorine? That’ll eat stainless right quick.

Stainless work hardens EASILY. Maybe the stamping process was done incorrectly… which would validate the cheap manufacturing process idea.
 
I read it was unpacked from something. If so, what was it packed in? The inside, what little I see, looks shiny like the other pots so the pot was degraded by something outside- perhaps the packing outgassed something, or something external to that. Was the outside washed in salt water?
 
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Tools said:
Any chance of exposure to bleach? Chlorine? That’ll eat stainless right quick.

Stainless work hardens EASILY. Maybe the stamping process was done incorrectly… which would validate the cheap manufacturing process idea.
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No chlorine/chemical exposure that I know of. I just boiled water then put it away on a shelf, in the mesh bag it came in. I’m sure it was a cheap manufacturing process but I’m still puzzled by the extent of degradation from one use. Makes my not want to even use the rest of the set on a real camping outing.

Cap'n Jack said:
I read it was unpacked from something. If so, what was it packed in? The inside, what little I see, looks shiny like the other pots so the pot was degraded by something outside- perhaps the packing outgassed something, or something external to that. Was the outside washed in salt water?
Click to expand...

I used it to boil plain old well water, then put it away on a shelf in the mesh bag it came in. It then got packed in a box for a couple of months, But nowhere near tightly enough to cause this kind of physical compression/ damage. The bottom of the inside is shiny, where the plastic dishes were. But the upper half is also discolored. 7295B758-98AA-4026-B840-3B47D5A4C515.jpeg

FORANE said:
It was shock cooling.
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.

If it is shock cooling, I’m still puzzled because it was cool and in one piece when I put it away. Could shock cooling have such a delayed effect, on such thin flimsy metal?
 
First thought prank/trick question, but if real I’d guess residual stress from the stamping/drawing process and hydrogen embrittlement from the boiling water making nucleation points for crack propagation.
 
drummer4468 said:
I used it to boil plain old well water, then put it away on a shelf in the mesh bag it came in.
Click to expand...
What's in your well water? Have you had trouble with stainless utensils before?
 
I've got a similar, though perhaps unrelated problem...my house came with a wet bar equipped with a round copper sink, maybe 16" across. The copper sink has a series of top to bottom cracks all the way around, much like the SS cookpot in this thread. I don't recall there being concave dishing between the cracks--I'll have to look next time I'm in the basement.
I do know I've been unable to find a round sink in any material that could be a drop-in replacement for what's there now.
 
Stress corrosion cracking, probably resultant from an inferior grade of stainless with most of the chromium out of phase, and residual stresses from the forming process.
 
Dan Thomas said:
What's in your well water? Have you had trouble with stainless utensils before?
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Nothing that I know of! I haven’t even done my annual shock treatment this year yet. No other issues with all my stainless cookware.

Flatiowa said:
First thought prank/trick question, but if real I’d guess residual stress from the stamping/drawing process and hydrogen embrittlement from the boiling water making nucleation points for crack propagation.
Click to expand...

a little above my knowledge level but it sounds believable lol. Especially with the perfectly vertical cracking and dishing, definitely smacks of stresses from the stamping/drawing process. Wondering if the pot was indeed overheated and somehow burned off some kind of protective coating. Because it seems to be fine below the water line (I don’t remember exactly how high I filled it)
 
those little thin metal camp pots get pretty hot above the water line...especially with some wide burner stoves...so wouldn't have to be dry necessarily
 
Looking at it further, I think it was just drawn too thin. When they form these things, they start with a piece of round stock that extends a little past the mandrel base, and it gets increasingly thin as it is formed over the mandrel shaft. Residual stresses will want to cause it to flatten back out in to a sheet, so if it cracks and splits, it will force a concave deformation because the metal can't stretch.

As to why the delayed reaction is a little bit puzzling, but the aforementioned hydrogen embrittlement (which could lead to stress corrosion cracking) could explain that. A cheap crappy stainless alloy would exacerbate* the problem.

*I learned a new word the other day. I'm going to start using it in normal conversation.
 
Sac Arrow said:
A cheap crappy stainless alloy would exacerbate* the problem.

*I learned a new word the other day. I'm going to start using it in normal conversation.
Click to expand...

Good for you. So many folks use "exaggerate" when the word they want is exacerbate. Exaggerate is a verbal thing; exacerbate is physical.
 
Sac Arrow said:
Looking at it further, I think it was just drawn too thin. When they form these things, they start with a piece of round stock that extends a little past the mandrel base, and it gets increasingly thin as it is formed over the mandrel shaft. Residual stresses will want to cause it to flatten back out in to a sheet, so if it cracks and splits, it will force a concave deformation because the metal can't stretch.

As to why the delayed reaction is a little bit puzzling, but the aforementioned hydrogen embrittlement (which could lead to stress corrosion cracking) could explain that. A cheap crappy stainless alloy would exacerbate* the problem.

*I learned a new word the other day. I'm going to start using it in normal conversation.
Click to expand...
I agree with stress from forming the pot is part of the cause. I also think there was something environmental contributing (exacerbating) the failure because the corrosion seems masked- other pots ans parts covered by something aren't corroded.
 
bflynn said:
When stored, was anything heavy on top of it?
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Nothing noteworthy, maybe a box of firestarters worth a pound or two.

Brad W said:
those little thin metal camp pots get pretty hot above the water line...especially with some wide burner stoves...so wouldn't have to be dry necessarily
Click to expand...

That's what I was thinking. But the delayed reaction and discoloration still confuses me.

Cap'n Jack said:
I agree with stress from forming the pot is part of the cause. I also think there was something environmental contributing (exacerbating) the failure because the corrosion seems masked- other pots ans parts covered by something aren't corroded.
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Come to think of it, I do remember accidentally placing the hot pan down on a plastic tabletop at one point and melting it a bit. When I started another boil test, I think some must have been stuck to the bottom because an INCREDIBLY acrid odor smacked me in the face as soon as the flame hit it. Like a rich-burning acetone or something. Maybe that contributed to embrittlement and whatnot.
 
I think there's a simpler answer. If there is a possible way to f&*&k something up that should be impossible to f()(k up, Walmart and their suppliers will figure out how to do it. Substitute any big box store for that as well. I'd bet dinner anywhere in this town that the pot is made of a alloy that doesn't correspond to any spec ever written by astm/sae/iso.

The amazing thing to me in this, is that people buy food there.
 
I bought a set of three nested stainless steel mixing-type bowls from THE big box: I don't think stainless steel is what I thought it was. . .if the bowls were thinner I could read through them. Or maybe through the one that lasted a year. . .

Took a long search, but I found a spring form pan made in the US . . .I make a killer cheesecake.
 
Sac Arrow said:
A cheap crappy stainless alloy would exacerbate* the problem.

*I learned a new word the other day. I'm going to start using it in normal conversation.
Click to expand...

Next you have to start using "ameliorate." It's even more fun.

You're doing better than some. I routinely see and hear the malapropism "exaggerate" incorrectly used when "exacerbate" was the intended word.
 
The "...ate" word I hear most often is "inappropriate". As in, it may be inappropriate to compare a PM to a parrot, that can't figure out they're looking at a mirror, not another parrot, when trying to understand technical things.

To me, the substitution of humor for swearing is an improvement I've made over the past 20 years, but some don't see it that way.
 
Just last night I looked for some scholarly articles on weather stainless can leach contaminants into food. I found one but haven’t read it yet. Probably not a big deal for an occasional camping meal…
 
Dan Thomas said:
Good for you. So many folks use "exaggerate" when the word they want is exacerbate. Exaggerate is a verbal thing; exacerbate is physical.
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Oh that's only the start. I hear homonyms and near-homonyms mixed up all the time. Drives this retired professor bat crazy, but I've learned to keep my mouth shut. With difficulty.
 
[QUOTE="Sac Arrow, post: 3395363, member: 7476"*]…exacerbate…[/QUOTE]
Can you do that to an admixture?
 
TCABM said:
[QUOTE="Sac Arrow, post: 3395363, member: 7476"*]…exacerbate…
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Can you do that to an admixture?[/QUOTE]

Excess exacerbation can lead to a malapropism. But, I'm sure the doctor can administer an admixture to remedy it.
 
judypilot said:
Oh that's only the start. I hear homonyms and near-homonyms mixed up all the time. Drives this retired professor bat crazy, but I've learned to keep my mouth shut. With difficulty.
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Just reading a newspaper or magazine can be disheartening. Even the "journalists" can't get the wording or spelling correct. What do they do in those years at university? What did they do in grade school? Surely not the three Rs.

Reading their reports of a lightplane accident is revealing. They have no idea what they're talking about. It makes one wonder about the accuracy of anything else you read.
 
I've seen several reports this morning that Tom Cruise accepted his MTV Movie Award for Top Gun Maverick yesterday while flying his fighter jet.
When he was clearly in his P-51.
 
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