Propeties of 304 stainless at 2000 deg F

[Kilmarnock]

I am working on a design of a basket used to melt aluminum flash and waste from a casting process from steel moulds. I have a plan in mind and leftover 304 ss bar from another job.
What I am looking for is the material properties of 304 at between 1800 and 2000 deg F. Overall weight is only a couple hunderd lbs but I would like to know with some confidence that there is still some strenght left in the material to hold the basket together at temperature. It would always be slow cooled.

 

[TStaples]

Kilmarnock,

I have a little experience with 304 Stainless used at approx 1800ºF, but it was extremely weak at those temperatures. Another 200ºF would concern me. 304 is generally not recommended above 1700°F, but we were able to push it to 1800°F semi-successfully.

309 or 310 might be a better choice, if those are an option.

Check out:

http://www.azom.com/details.asp?ArticleID=1175

-Tony Staples

http://www.tscombustion.com

 

[arunmrao]

Ordinary grey cast iron will perform better than 304. Normally above 600C 304 is not used. If costs permit you can try 309 or 310.

 

[EdStainless]

At 1800F the strength will be under 10ksi.
Cast iron in a better option.
There are no resonable cost alloys with any significant strength at these temps.
Have you considered refractories?

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[NickE]

Also you wouldnt want to slow cool 304 from 2000F. Sensitization would result.

 

[CalvinKelly]

We have seen 304 approximately 1/4" thick disappear completely from oxidation in a few months at 1700-1800F. One reason you cannot find mechanical data for 304 above 1500F is that the oxidation resistance is too poor to make a good test specimen. Agree there are no reasonably priced bar alloys, at this time, for 2000F service. The most available grade with some kind of strength and decent oxidation resistance is RA330, 35%Ni 19%Cr 1.2%Si (UNS N08330, ASTM B 511) If you can use flat bar (round not available at this time), 253 MA, UNS S0815, ASTM A 240) is maybe a little stronger, good oxidation resistance and very much less expensive. 253 MA has roughly twice the strength of 309 or 310.
Don't let molten aluminum splash on the metal. Molten Al acts like the Universal Solvent and will go through nickel alloys like, well, hot water through snow.
James Kelly

James Kelly

http://www.rolledalloys.com

 

[kenvlach]

I have to say that the OP is a bit puzzling:
"design of a basket used to melt aluminum flash and waste from a casting process"

So, why are 1800-2000 ^oF properties needed?

CalvinKelly is absolutely correct about liquid Al attacking Ni-containing alloys, although depending upon conditions, it may be more like arthritis (formation of a skeleton of very strong but brittle aluminide AlNi, like Raney catalysts).

I recall using yttria- and zirconia- brush on coatings from ZYP to protect graphite, clay graphite & cast iron crucibles & molds when melting & casting aluminum. Also, fluxing/degassing tablets used with molten aluminum are incompatible with stainless. Maybe post a question on melting aluminum in the Metallurgy forum, as swall & others there have lots of experience.

 

[arunmrao]

I do not understand the term basket for melting Al flashes. I make cast crucible for holding Al molten metal in this chemistry.
Cr 24-27%, Ni 3% min, C 0.2-0.6%, Mn 0.6-1.0%, Si 0.8-1.1%, Va 0.4-0.6% and Mo 0.1% min.

This crucible has a life of 9 months and is then replaced. No welding repair is possible.