Cryogenic processing, the deep chilling of tool steel so that the molecular of the metal is brought to "cryogenic stillness" in order to improve wear characteristics, is not a new technology. In the past tool makers would bury components in snow banks for weeks or even months to improve their wear resistance. Castings were always left outside in the cold for months or years to age and stabilize. Today's dry process is computer controlled, using a prescribed schedule and maintained at -300 °F for a particular time before slowly returning the parts to room temperature. Prior to the deep cryogenic step, many tool steels require a preconditioning step consisting of a short temper. After being subjected to the deep freeze, the materials must be tempered to about +300 °F. This temperature varies for different materials, and the processing time varies for different material cross sections.
Improve performance and increase the life of metal cutting tools, blades, punches, dies, slitters, shears and knives with cryogenic processing at -300 °F. Cryo processing increases abrasive wear resistance, raises the tensile strength and decreases brittleness with only one permanent treatment. It creates a denser molecular structure and closes the grains structure, resulting in a larger contact surface area that reduces friction, heat and wear. Cryogenic treatment changes the entire structure, not just the surface. Subsequent refinishing or regrinding operations do not affect the permanent improvements of the processing.
When the cryo treated tool does wear, the degree of wear reportedly is less severe, slower and more uniform. Therefore, less material must be removed to re-sharpen it. Customers have reported a material removal rate of less than half the normal material removed in re-sharpening. Cryo treating reduces the cost of the product by having longer tool like, less scrap, fewer rejections and above all, less costly downtime. Gains between 50% and 500% may occur, depending on the component structure and previous heat-treating. Every application is unique and the benefits for each one is application specific. There is no blanket prediction that can be made or previous results used to guarantee the same results for every operation. Each one has to be tested.
Cryogenics is not a substitute for heat treating; instead, it simply adds the finishing touch to the heat treating process. It completes the austenite-to-martensite conversion in tool steel.
Another benefit of cryo treating is its ability to make the grain structure more uniform, which ultimately improves dissipation of heat beneficial to the racing industry.
Durability is the most important criterion used to define the quality of a gear. Cryogenic treatment will provide high quality products with enhanced performance. It allows an increase in fatigue life, load capacity and wear resistance of gears without an increase in weight or major modifications to component design. Racing teams will reduce costs and often prevent destructive failure. The process is not a coating, but a permanent irreversible change completely through the metal part. Gears may be new or used, sharp or dull, resharpening will not destroy the treatment. Potentially every gear that is heat treated is a candidate for the additional service of cryogenic treatment.
Cryo treating can be used for coated as well as uncoated tools. The coatings actually adhere better. Anodized surfaces or metals, such as aluminum, also obtain longer life. Cryo also creates a better conductor, giving the metal better electrical conductivity.
"Today's limited acceptance and use of cryogenic treatment is basically attributed to a lack of understanding the technology," said a company spokesperson. Changes to the material micro structure are not visible with a standard laboratory metallograph or any other standard mechanical testing. Material hardness remains about the same.
There are a variety of items that benefit from cryogenics such as racing engines, guns, knives, aluminum softball bats, punches, dies, golf club heads, high end audio equipment, brass instruments, guitar strings, vacuum tubes, CDs and DVDs.
For more information contact:
CryoPlus, Inc
2429 N. Millborne Rd
Wooster, OH 44691
330-683-3375
www.cryoplus.com