High Temperature metal

[Bobfromoh]

I am trying to select a metal plate that will operate in an 1850F enviroment. The process runs for about 1000 hrs. a few holes will be drilled in the plate for gas flow. There will be a small pressure drop load over a surface area of 50in2. I was looking at Inconel 625.
Are there other metals in small quantities. Price is a slight issue but need delivery ASAP.

 

[metengr]

What kind of gas????
Look at Incoloy 800HT

http://www.specialmetals.com/products/index.php

 

[Bobfromoh]

Thanks for the response. I can't say much about the process...proprietary. It's hot and noncorrosive. I know all about the various web sites from supplies showing the various metals accompanied by a data sheet. Is anybody actually using a metal in an 1850F enviroment? What other materials did you look at?

 

[MikeMet]

Metal are used at your operating temperature all the time. You can not ask for help here with out giving some process data because of the various forms of high temp corrosion that can occur based on what is in the gas, such as oxidation, sulfidation, deterioration from high temp nitrogen and chlorine, carburization etc. And one alloy is not good for all these types of degradation. If you can not give gas compositons, recommend you go the Haynes Alloy website and look at high temperature alloy data to help you select your alloy

 

[unclesyd]

I totally agree with MikeMee that there isn't enough information to give the proper response.
Aside from the Haynes recommendation posted above you may want to get in touch with HP Alloy or High Temperature Alloy where I think you will stand a better chance of getting small quantities quickly.
You may even have to sign a confidentiality agreement if you need to hold back all information.

http://hpalloy.thomasnet.com/category/high-atemperature-heat-resistant-alloys?&plpver=10

.

http://www.hightempmetals.com/technicaldata.php

As I Was told many yeas ago without environmental information at these temperature you may have to go with Unobtainium.

 

[EdStainless]

Is the gas oxidizing? If not much then what about 2Cr 1/2Mo, it is what they use for boiler tubes.
1000 hr is a short exposure, only six weeks.
If it continuous or cyclic?
you could do this with 430, or a step up would be 310.

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Plymouth Tube

 

[blacksmith37]

For such a limited size , I would say availability would be more of a consideration than cost/alloy. If you can't locate plate (any Inconel 6XX, 7XX, Incoloy 8XX, 310, 309 ) ; a foundry may pour a "sample" of HK, HH, HP, etc. I would avoid the ferritics (4XX) because of sigma phase embrittlement (It may not be a problem for your service, but why find out?)

 

[davefitz]

It may also be possible to design the device so that a less exotic material could be used, for example , if the gas was low temperature, the gas could first pass thru 2 parallel plates and be used as a cooling medium, simlar to some designs in gas turbine combustors.

 

[BillPSU]

You may want to consider utilizing a nickel aluminide based intermetallic alloy. The strength characteristics of the material is unusual as max yield strength is achieved at an elevated temperature approaching 900 degrees C and the material has excellent high heat corrosion resistance. I have read several research papers on the various intermetallic materials and the application you are describing sounds like a good fit for the material. I am not aware of availability or pricing of the material.

 

[Bobfromoh]

I want (need) to use Inconel 625 because of availability. The plate must support a load of about 400lb. What value of allowable stress at 1850F would be used for this application. I would think that values based onthe AISC Code would work? I don't want the plate to fail but if it does, it's inside a vessel.

 

[EdStainless]

How will this be supported?
You probably don't want to weld around all of the edges, you could create huge stresses from the welded and differential thermal expansion.
Go ahead and use the code stress numbers, but don't be afraid to go higher since this is not for pressure containment.

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Plymouth Tube