Duro-Chrome Industries Inc. established a new division to handle its recently introduced cryogenic mold-tempering services.
The Wauconda, Ill., firm claims its cryogenic process improves wear resistance, reduces residual stress and increases tensile strength in tool steels. The process also is suited to molds made of aluminum alloys and other materials, said John Snelgrove, sales manager of Absolute Zero Co. Inc., Duro-Chrome's new division.
Snelgrove said cryogenic tempering entails chilling a mold or mold components to minus 300° F for about 48 hours, then heating the tool at 300° F for several hours. The process stabilizes the molecular structure of the tool metal. In steel, for example, austenite structures are converted to martensite.
Duro-Chrome began offering cryogenic tempering for molds about six months ago and promising results prompted it to establish a new division. Duro-Chrome's main business has been chrome-hardening of steel and mold polishing.
The company said cryogenic tempering conditions the entire mold or component, and not just the surface. Unlike surface treatments, cryogenics is a one-time process that provides better dimensional tolerance.
Cryogenic treatment long has been used in military and aerospace applications, but Duro-Chrome predicts it is cost-effective for plastic molds as well. Snelgrove said treatment cost varies by part weight, but starts at about $10 a pound for small molds and runs to about $2 a pound for molds weighing 5,000 pounds. It charges a minimum price of $50.
Duro-Chrome is working to make cryogenics compatible for parts previously hardened with a titanium nitride coating. Absolute Zero President Donald Doherty said his division wants to use cryogenics to minimize tool distortion caused by such coatings.