Inspired by this question How devastating is a weapon that can internally and rapidly cool down a section of a human body?, I wonder what kind of blacksmith method could be used for forging or smithing a sword or other melee weapon with a metal that constantly has ice cold temperature below zero.
Assuming the metal still has steel hardness or has high quality spring steel/high quality carbon steel properties outside of the melting point due to it constantly in below subzero temperature.
And outside of cold working method and casting method.
There's no specific timeline regarding the technology to forge it, so it's fine if the method is a futuristic one as long it's hypothetically/theoretically possible, but would be better if there's a way for traditional method though.
I am not knowledgeable about metallurgy or blacksmithing in general, just wondering if there is any other unique method for forging such a thing, hence I exclude cold working which I think is the common way to deal with this while keeping the quality/hardness of the metal that I know of (assuming it even works for such metal, so correct me if I am mistaken).