Low temperature carbon steel.

[Timewrap]

Dear Experts,

I'm designing a system where a reactor is cooled using liquid nitrogen inside a jacket around the reactor. The boilig point of liquid N2 at atmospheric pressure is about -196 deg C. I'm sure that the SS 304/316 could not be used at this low temp. I'm certain, it gotta be low some grade of low temperature carbon steel.

Can you throw some light on the material selection??

Thanks in advance,

Timewrap.

 

[metengr]

Timewrap;
An austenitic stainless steel like 304/316 is quite suitable for cryogenic service. Is this a reactor a pressure vessel?

 

[Timewrap]

Thanks Metengr for the reply,

The reactor is operating at few pounds gauge pressure, just a little over atmospheric pressure.
I've heard that 304/316 display maximum cryogenic strength at -46 deg C. So, that's not true, up to what temp. these austenitic steels go??

Thanks,

Timewrap.

 

[TVP]

Austenitic stainless steels like Type 304 or 316 are routinely used at cryogenic temperatures, meaning below - 200 C. These grades are used for pipes and tubes for refrigeration and transportation of cryogenic liquids, for equipment exposed to low temperature/low pressure environments in space and on Earth, as well as for structural applications like threaded fasteners for flanges, etc. It sounds like you would benefit from consulting with some experienced mechanical and metallurgical engineers in order to understand the materials to use for this application.

 

[DVWE]

ASME VIII Div 1 exempts pressure vessels constructed of 304/316 from impact testing clear down to -320 F. So that should tell you something about the suitability for cryogenic service.

 

[strider6]

stainless steel can be used at very low temperature(cryogenic) , while carbon steel are usually selected for temp down to approx -40°C.


"Austenitic stainless steels are extensively used for service down to as low as liquid helium temperature (-269 deg C). "
Can I use stainless steel at low temperatures?

http://www.bssa.org.uk/faq.php?id=26

Selection of stainless steels for cryogenic applications

http://www.bssa.org.uk/topics.php?article=41

hope this help

S

Corrosion Prevention & Corrosion Control

 

[Timewrap]

Thanks all,

For all you valuable posts.

Timewrap

 

[weldquals]

You can also used 9% Nickel (A553 Type 1)

9% Nickel Steel

High strength (100ksi UTS)
Excellent cryogenic toughness to –320F
Note: Weld metal is normally nickel alloy
Nickel content provides
Good hardenability when quenched
Tempering cause reversion of 10-15% of steel to austenite (produces the toughness)

 

[SnTMan]

Code also allows use of just about any non-ferrous at extremely low temps. Aluminim, copper, etc.

Regards,

Mike