Cryogenic processing had its US origins in the 1940s, be it all a primitive process compared to today's procedures.
Steel cutting tools were immersed in liquid nitrogen for a brief period of time, removed from the liquid, allowed to warm up, and placed into service on production lines. As a result of the thermal shock associated with the rapid rate of cooling, tools tools would occasionally crack or chip. Some tools also became brittle because of the newly formed, untempered martensite. Of the tools that survived this crude quenching, many exhibited dramatically enhanced service life.
In addition to developing the correct medium, a method to reduce thermal shock had to be developed. Elimination of thermal shock is critical. This is achieved by strict controls in the lowering and raising of temperature in the treatment cycle that is critical to the commercial application and effectiveness of cryogenic processing.
Cryogenics is a relatively new process, but one that using correct proceedures can bring substantial economic benefits. Cryogen Industries makes a clear statement that process doesn't work on everything nor is it a miracle cure-all. If a product is found by us not to be worth treating due to poor manufacture or the item will yield little to no return for the customer, we won't treat it.
Cryogenic processing makes changes to the structure of materials being treated, dependent on the composition of the material it performs three things:
1. Turns retained austenite into martensite
2. Refines the carbide structure
3. Stress relieves
Steel cutting tools were immersed in liquid nitrogen for a brief period of time, removed from the liquid, allowed to warm up, and placed into service on production lines. As a result of the thermal shock associated with the rapid rate of cooling, tools tools would occasionally crack or chip. Some tools also became brittle because of the newly formed, untempered martensite. Of the tools that survived this crude quenching, many exhibited dramatically enhanced service life.
In addition to developing the correct medium, a method to reduce thermal shock had to be developed. Elimination of thermal shock is critical. This is achieved by strict controls in the lowering and raising of temperature in the treatment cycle that is critical to the commercial application and effectiveness of cryogenic processing.
Cryogenics is a relatively new process, but one that using correct proceedures can bring substantial economic benefits. Cryogen Industries makes a clear statement that process doesn't work on everything nor is it a miracle cure-all. If a product is found by us not to be worth treating due to poor manufacture or the item will yield little to no return for the customer, we won't treat it.
Cryogenic processing makes changes to the structure of materials being treated, dependent on the composition of the material it performs three things:
1. Turns retained austenite into martensite
2. Refines the carbide structure
3. Stress relieves
No comments:
Post a Comment