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 to forging or smithing a sword or other melee weapon with a metal that constantly has ice cold temperature below subzero.
assuming the metal still is in 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.
theres no specific timeline regarding the technology to forge it, so its fine if the method is a futuristic one as long its hypothetically/theoretically possible, but would be better if theres a way for traditional method though.
i am not knowledgeable about metallurgy or blacksmithing in general, just wondering is there other unique method for forging such thing, hence i exclude cold working which i think the common way to deal with this while keeping the quality/hardness of the metal that i know of (assuming it even work for such metal, so correct me if i am mistaken).
feel free to edit my grammar/sentences and the tag to be appropriate