noun
subzero treatment; deep cooling
Technical term used in materials science and engineering for cooling materials to very low temperatures, often to improve properties like hardness or wear resistance.
工具鋼に深冷処理を施すと、耐摩耗性が向上する。
Applying subzero treatment to tool steel improves its wear resistance.
Compound of 深 (deep) + 冷 (cooling) + 処理 (treatment). The exact historical derivation is uncertain; the spelling is conventionally associated with the meaning.