Stainless & Carbon Steel at 22 degrees F

[Bagman2524]

I'm looking for information on how Carbon Steel (A36) and Stainless Steel (304 or 316) are affected by low temperature (22 deg F). Any help would be appreciated.

 

[SMF1964]

As a general observation, carbon steel can be brittle at 22 °F. There is more to it than that, since composition, heat treatment and things like that can influence the impact properties of carbon steel. Austenitic stainless steels (such as 304 or 316) do not get brittle at these temperatures. Will need much more information.

 

[redpicker]

To expand on what SMF1964 said, the carbon steel can change its behavior on cooling from room temperature (70 deg F or so) to lower temperatures. This means that a structure that was sound at warmer temperatures can become unstable (catastrophic failure) at lower temperatuers even though the loading has not changed. The magnitude of this effect is dependent on the composition, heat treat, etc... as SMF said.

This does not happen with the 300 series stainless steels.

rp

 

[stanweld]

A-36 steel (body centered cubic crystal structure)undergoes a ductile to brittle transition with declining temperature. At 22F it may or may not be brittle depending on chemistry and thermal and mechanical processing. Fully austenitic materials (face centered crystal structure)like 304 SS do not.

 

[Bagman2524]

Thanks for all the input. The info provided is very helpful.

 

[JStephen]

FYI- how the tank codes handle:
Old code, still used: Use relatively low stresses and can use A36 up to 1.5" at any temperature.
Newer version: Use A36 up to 1/2" thick down to +20 F.
Other newer code: Use A36 up to 1/2" at similar temps. Or use A36 with increased manganese content up to 1" or so. The increased manganese content makes it very similar to A131-B. A lot of the standard A36 will meet that requirement anyway.

So, unless you're using real thick plate, you're probably okay at that temp- need to use proper weld procedures and all.