Cold Temperature Metal Properties
Cold Temperature Metal Properties
(OP)
I understand that if metal undergoes a cold temperature excursion, its mechanical properties (e.g. ductility, yield strength, tensile strength) should return to "normal" once the material warms back to ambient temperature. Would carbon steel (say, A106) material return to "normal" properties if it underwent an extreme cold temperature excursion? If the temperature dropped to -300 Deg. F, and the temperature eventually returned to ambient (70 Deg. F), would the mechanical properties of the steel have been compromised permanently?
Thanks.
Thanks.





RE: Cold Temperature Metal Properties
I am very interested in this question, hope someone might know ,,
Just by guessing, according to me, should be back to normal since at such temperature -300F, no microstructure change will happen, so the properties should be the same...
however, in normal sense if you freeze an apple and then put it back it wont be the same tho..that's due to the chemical reaction/ water expending while freeze, so if metal shrink at low temperature.. will the microstructure the same? i doubt..
RE: Cold Temperature Metal Properties
RE: Cold Temperature Metal Properties
RE: Cold Temperature Metal Properties
Result: No change in impact properties
Considering grade A106, I would expect no change, if no applied loading was done.
RE: Cold Temperature Metal Properties
However I can think of a few exceptions, such as alloy steels that require cryogenic temperature treatment to undergo complete transformation to martensite, the desired structure. Cryogenic temperature could also effect the activity of interstitial elements in some alloys.
"If you don't have time to do the job right the first time, when are you going to find time to repair it?"
RE: Cold Temperature Metal Properties
1. A slow drop in temperature will cause point defects out of the crystal structure. In the end there will be fewer vacancies in the matrix.
2. The solubility of the alloying elements in the matrix will change. This is part of the driving force that causes the formation of tiny carbide particles in the steel. Carbon is precipitated out and joins with any carbide forming elements.
3. The metallic bonds that have extra energy due to atoms not being at the precise most efficient distance from each other may lose that energy and the crystal lattice structure will become more regular.
If the temperature drop is sudden, for instance created by dropping the part into liquid nitrogen, there will be the creation of large temperature gradients at the surface, which can cause residual stress or cracks. The changes listed above will not have enough time to happen.
RE: Cold Temperature Metal Properties
)the thermal expansion coefficient which is undesirable. While Invar (Fe-36Ni) never has this problem.
RE: Cold Temperature Metal Properties
Why wouldn't martensite form that would need tempering?
RE: Cold Temperature Metal Properties