Cryotron (Canada) Ltd.

CA

The Cryotron process is based on a predetermined thermal cycle that involves cooling of the tools/parts in a completely controlled cryogenic chamber. The material is slowly cooled to - 320F (-196C) and 'soaked' at that deep cryogenic temperature for 20-40 hours. The material is then allowed to return very slowly to ambient temperature. The complete cryogenic cycle can take up to 72 hours to complete. This procedure of precisely controlled temperature profiles avoids any possibility of thermal shock and thermal stress that is experienced when a tool or part is subjected to abrupt or extreme temperature changes. Though liquid nitrogen is used as a refrigerant, no material is introduced to liquid until it has been slowly cooled to cryogenic temperatures by ultra-cold nitrogen gas.

The Cryotron procedure eliminates the need to apply protective coatings, such as WD-40, to materials prior to cryogenic treatment. Moisture does not accumulate in a Cryotron chamber.

Cryogenic processing is not a substitute for heat treatment, but rather an extension of the heating / quenching / tempering cycle. In most instances a heat tempering procedure follows the cryogenic cycle. As all alloys do not have the same chemical constituents, the tempering procedure varies according to the materials chemical composition, thermal history and/or a tool's particular service application.

Results & Benefits

Cryogenically treated materials show a marked increase in wear resistance without any discernible change in dimensional or volumetric integrity. Machining treated material is easier and cleaner. Redressing or regrinding treated tools removes less stock material resulting in longer tool life. Although the material is stronger following treatment, it shows little or no change in yield or tensile strength. The treated material becomes less brittle, without a change in original hardness. The most significant and consistent change is the increased toughness, stability and wear resistance. The Process is also used extensively to relieve residual and tensile stresses.

Two main changes in the microstructure of the steel occur as a result of Cryogenic Treatment. These changes are the principal reasons for the dramatic improvement in wear resistance.

First, retained austenite - (a softer grain structure always present after heat treatment) is transformed into the harder, more durable grain structure - martensite. The range of retained austenite in a material after heat treating may be as high as 50 % or as low as 3 %. The amount depends on the heat treating operator and the accuracy of the heat treating equipment.

A major Alberta Sawmill Operation has reduced a particular tooling cost by $10, 000 annually by utilising Cryotron's unique cryogenic process.

Other Relevant Information: Cryotron (Canada) Ltd. has developed a customer list of over 200 clients that consistently use our services. The proven technology of cryogenic processing has generated a rapidly growing market. The demand for processing has created a market demand for equipment. Cryotron Processing Equipment is recognised as an industry leader in this developing technology. Cryotron supports the following Industries:

Machining and Manufacturing - Cryogenic Processing of Machine Tooling to extend useful life.

Forestry - Cryogenic processing of dynamic parts and Machine Tooling The process substantially reduces unscheduled downtime and increases productivity.

Oil & Gas - Increases the life of perishable tooling such as slip inserts, down-hole tools, and equipment parts. Croyton Cryogenic Systems are in place with several major manufacturers in the US, Africa, Europe, and Asia. Details provided on request.

332999

United States