Abstract: Apparatus and method for construction of a rectangular deep cryogenic treatment chamber using an insulated, steel structure capable of large size and large volume cold thermal treatment. Apparatus includes end or top-mounted closure, liquid nitrogen delivery and distribution mechanisms, fan motors, cold diffusion-less thermal exchange, external heating element, electrical wiring and machined components. The design facilitates both low temperature, dry vapor thermal processing of metal and metal-matrix components down to ?320° F. to enhance wear, corrosion, mechanical, thermal and electrical characteristics, and also post-cryogenic tempering capability to 300° F. The apparatus describes an external, LN2 storage dewar and solenoid-activated, gravity fed cryogen delivery via distribution hubs and distributed flow tubes. The apparatus also describes integrated deep cryogenic treatment authentication, test, validation and certification equipment.

Abstract: Apparatus and methodology for the ultralow temperature processing of metallic, carbide, ceramic and plastic parts and items to materially increase their wear, abrasion, erosion and corrosion resistivity, stabilize their strength characteristics, improve their machinability and provide stress relief. The cryogenic treatment processing is carried out in an insulated box-like treatment chamber which includes a perforated platform extending parallel to and spaced above the bottom of the chamber. Parts and items to be treated are supported on the platform and cryogenic liquid is introduced to the chamber below the platform in accordance with a time-temperature program which reduces the temperature of the parts and items in stages to -320.degree. F. by initial cooling of the parts and items by evaporating vapors from the cryogenic liquid pool in the space below the platform and thereafter by partial or substantial submersion of the parts and items in the cryogenic liquid. After a soak period at the -320.degree. F.