400 Series Stainless - Can it Burn 3

[littlekix]

Hello all,

I have come across a difficult question and was wondering if anyone can point me to some literature. I have a 400 series corrugated thin plate (409 or 410, hard to tell with PMI due to sever scale) that has literally "burned up". I am trying to figure out if it is even possible for a stainless to "burn"?

I am familiar with thermite, which involves aluminum and rust Fe2O3 (or few other variants as oxidizers) which releases a serious amount of energy, but this is not an easy reaction to get going. On most experiments I did in my delinquent youth it involved very small piles of powder in chem lab experiments for show and tell days. Even then it was hard to get a "good one" for the 8th graders.

Can something similar happen with stainless oxidizing with something? I am not a chemist and have never heard of something like this happening.

For background, (sorry that I am vague, can't say much) this material was at the back end of a furnace. They noticed a fire and had trouble putting it out. Water didn't work and they were required to use a foam to put it out. At the end of the day was left with giant pile of what looks like melted and burned scale (was supposed to be 304 tubes with a 400 series thin plate)

Any thoughts?

 

[metengr]

No, it does not burn. It can melt if exposure temperatures are high enough. Your observation is severely oxidized ferritic stainless steel - loss of material, discoloration, etc., which requires exposure to elevated temperature and oxygen in the atmosphere.

 

[macmet]

Agree with metengr. Sounds like something fun you could test to prove as well. Just be careful.

 

[EdStainless]

Well, according to NASA you can burn 410SS, even in less than pure oxygen, but the ignition temps are on the order of 1300C (which is very close to the melting point).
It is more likely that this was exposed to a very high temp and oxidized so severely that there is no metal left, just scale.

My hunch is that there was a residue on the heat exchanger (carbon maybe) that caught fire. At high temp in air you will destroy SS by catastrophic oxidation.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

 

[racookpe1978]

Could the heat have been held up high enough to precipitate out (disassociate) the "stainless metals' from the carbon steel and carbon molecules inside the tank wall crystal matrix, then those sustained temperatures (a little bit later during the life cycle) support a chemical reaction on the (now-unprotected) carbon and iron molecules and the contents of the tank?

 

[mrfailure]

I actually had to deal with this question for a project. EdStainless is right: 400-series (or really any steel) can burn at a high enough temperature but usually very high oxygen concentrations are required.

Aaron Tanzer

http://www.lehightesting.com

 

[berkshire]

Think what an oxy acetylene torch does.
B.E.

"A free people ought not only be armed and disciplined, but they should have sufficient arms and ammunition to maintain a status of independence from any who might attempt to abuse them, which would include their own government."
-George Washington, President of the United States----

 

[littlekix]

Maybe I am mistaken, but as I understood oxy torches melt the steel with the oxy acetyl mixture and then when you hit the handle or valve it gives a blast of oxygen. This doesn't burn but instead pushes the molten metal out of your way. This in turn enables the oxy to melt the next part etc. in this way you are not burning the metal but melting it and pushing it out of the way. As stated above, to actually burn you need near perfect conditions which never exist when I am cutting scrap steel with a torch.


Ty Ed for the NASA reference, I found a good paper on oxy systems and the materials they use for them.

 

[metengr]

Earlier you had asked for a reference on this subject. Here it is for your review...

https://www.airproducts.com/~/media...ygen-steelmaking-metallurgist-perspective.pdf

 

[Compositepro]

The difference between severe oxidation and burning is mainly semantics. Stainless steel will oxidize/burn. Deposits on the steel can catalyze oxidation. Corrosion and oxidation products can form an insulating layer that trap the heat of oxidation and lead to a self-accelerating reaction.
An oxy-acetylene cutting torch does, indeed, burn the steel in the kerf of the cut. The burning steel is the primary source of heat in the cutting process.

 

[littlekix]

Ty metengr and compositepro for the info, I stand corrected and much better informed. Metengr that is a great reference regarding oxy cutting, ty.