Choose Steel Type for High Temperature Furnace 1

[K8eng]

I am designing a tool that will go into a heat furnace at 850F degrees for 30 minutes, and need to decide what grade steel to make the tool out of. I was originally thinking 304 or 316SS due to its high temperature properties, but cost is significantly more than A36 or a low carbon steel. Trying to determine what grade, or ASTM spec of steel would work for this application? Note, structurally this tool will not be withstanding high loads. Thanks all..

 

[dvd]

Approximate dimensions, sketch, loading, etc, etc

 

[EdStainless]

850F is a low temp. High temp is over 1900F.
You could use SS, any 300 series would work.
Plenty of steels would work also.
Will there be air in the furnace?
Will oxidation hurt your parts?
Unless you need special strength or oxidation resistance use a plain steel.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[K8eng]

Ed, Thanks for the info. Yes, there will be air in the furnace, it is actually a temperature chamber. More like an oven. Oxidation wont hurt the parts, they will only be used a few times before retiring. No strength needed. One tool is a pressure cap that will be seeing 300psi at 850F temp. Standard A36 low carbon grade steel should suffice I believe.

 

[JStephen]

Assuming this is plate, check in the material tables in the ASME boiler code. Some of the materials (such as A36) have notes about ill effects that can crop up eventually- likely not an issue for "a few times", tho. Also, you can find hot yield strength for different materials.
In pressure-vessel use, SA 516-70 is commonly used and available, so it would be another carbon steel option- generally in plate only, not structural.

 

[BridgeSmith]

I'm no expert, but in other applications where parts are exposed to those temperatures, cast iron seems to be the material of choice. If a cast piece could work, it may be worth considering.

Rod Smith, P.E., The artist formerly known as HotRod10