cold temperature effects on structrual steel? 1

[mtalexander]

Is there any type of factor to use when trying to determine the effect of cold temperature on the Tensile stress properties of a structrual steel? More exact I am looking for a factor from room temp to -4 degrees F. Thanks for the help.

 

[minerk]

Reducing temperature increases tensile strength, however for the temperature range you're looking at I would think it would be negligable.

 

[CWIC]

Notch toughness (impact) properties are typically a concern a low temperatures. This may be an attribute of the material that may require more looking into.

 

[dowens]

I found few references to the effect of temperature on strength (ultimate or shear) in this temperature range. Found some data on yield strength v. temperature starting at 70 deg F and going up to 800 deg F, and some data on cryogenic materials. For example Inconel 718 specs show an ultimate strength of 226,000 at 70 deg F increasing to 291,000 at -423 deg F. Based on this data only, you are not going to see a measurable difference between room temperature and -4 deg F. You will also see a slight effect on the Modulus of Elasticity with changing temperature. Most important to consider is the Nil Ductility Transition Temperature or Transition Temperature of the material you are using. Higher carbon steels get brittle at temperatures well above your low range.

 

[arto]

Life the folks above say - watch out for brittle failure!

You don't want a "whoops!" like this:

http://www.twi.co.uk/j32k/protected/band_13/oilgas_caseup31.html

http://www.mech.uwa.edu.au/DANotes/fracture/maritime/maritime.html

the ASME B&PV Code has info on this subject in Sec. VIII Div.1 par. UCS-66

 

[MJCronin]

mtalexander,

I believe a good refernce for you is the API-650 code on stell tanks....A36 carbon steel is permitted for use in tank shells to -4F and lower without any concern for brittle failure

The first cousin of A36 is ASTM A53/A106 Grade B (piping material). Use is permitted to -20F according to ASME B31.1/B31.3, however this is a "fully killed" steel and properties are slightly better than A36.

What does the AISC manual say about this....


MJC

 

[waskillywabbit]

As already mentioned, the ASME Boiler and Pressure Vessel Code has info on this subject in Sec. VIII Div.1 par. UCS-66. Most CS has an MDMT to -20F or even lower, yet UCS-66 suggest ways to get around this if your MDMT is not that low.