Our processes are based on what is placed in the chamber so each run is custom tailored to achieve the best results. It starts with placing the parts in a controlled cryogenic chamber and the ramp down starts with ultra-cold nitrogen gas. The materials are slowly cooled with nitrogen gas only and then slowly introduced to liquid nitrogen for the duration of the “soak” period. (20+ hours depending on what is being treated)
The liquid phase provides the most efficient and uniform deep cryogenic soak at a consistent temperature of 320 deg. F (impossible to do with gas alone).
With cryogenics two factors that make for a better end product are temperature (the colder the better) and time (the longer the better). Materials are then allowed to return very slowly to room temperature. At that time, those materials that specifically require post-cryo tempering are moved into a tempering oven to complete the tempering procedure. Some cryogenic companies use gas only treatment methods and only reach 300*, they promote the misconception that only dry noncontact liquid nitrogen is safe. Our research has shown that gas, by its natural properties, can be blocked from regions in the bath and a uniform 320* cannot be achieved by a gas only process. Our total liquid immersion method ensures that all areas of your product will be treated evenly at the desired 320* which achieves a vastly superior product.
The use of precisely controlled temperature profiles avoids any possibility of thermal shock and thermal stress that is experienced when a part is subjected to abrupt or extreme temperature changes. Though liquid nitrogen is used, no part is introduced to the liquid until it has been slowly cooled to cryogenic temperatures by the ultra-cold nitrogen gas. By eliminating the need for circulation fans and on-board heating elements are chambers remain 100% moisture free during the entire process. So our process does not require any anti-oxidants to be applied prior to processing.
Cryogenic processing is not a substitute for heat treating, but rather an extension of the heating/quenching/tempering cycle. As all alloys do not have the same chemical constituents, tempering procedures vary according to the material’s chemical composition, thermal history, and/or a part’s particular service application.