carbon steel low temperature application 1

[AVD]

Does anyone know whether medium carbon steel/medium carbon boron steel components can be stored at -50ºC and serviced at -40ºC regarding to shear and tensile strength? I know generally these steels shall not be used below -50ºC because they will become brittle.

Many thnaks in advance!

 

[metengr]

AVD;

Does anyone know whether medium carbon steel/medium carbon boron steel components can be stored at -50ºC and serviced at -40ºC regarding to shear and tensile strength?

Can you re-state the above, what does stored and serviced mean?

 

[strider6]

It would be necessary to define exactly the type of equipment or component and the service you're talking about to know which code to apply.

If you are talking about pipe or vessel equipment, you've to look for example in Code ASME B31.3 or ASME. You'll find the minimum temperature for the materials you're considering.


hope this help

regards

Vitt

http://www.corrosionist.com

 

[AVD]

Metenger/strider6

Thank you very much for your reply. The materials are medium carbon/medium carbon boron steels and the components are fasteners. I do not know what the application will be, and the only information is the fasteners will be stored at -50ºC and be used at -40ºC.

The fastener has two parts: body and stem. The body is annealed to ~150HV, and the stem is hardened & tempered to 380-430HV. When assembly the two parts to application, the body will be deformed and the stem will be broken at the pull groove. So the stress will include shear and tension during assembly.

Because the body has to be soft enough to deform, and the stem has to be strong enough but not brittle for assembly, I am worry at -50º/-40ºC the material will become too brittle to function properly.

Any advices are appreciated.

 

[metengr]

AVD;
Do not use this material for fasteners at -50 deg C. For guidance, please see ASME B16.34 for bolting materials that should be used with valve bodies for low temperature service. Medium and low alloy steel with boron will exhibit very poor notch toughness. The issue is notch toughness, not strength at this low temperature.

 

[CoryPad]

Another good reference is ASTM A 320/320M Standard Specification for Alloy/Steel Bolting Materials for Low-Temperature Service. If you don't have this, you can obtain it from ASTM International:

http://www.astm.org

Regards,

Cory

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