A certain amount of retained Austenite may always be found in hardened steel. Retained Austenite reduces the hardness, wear resistance and thermal conductivity of steel and makes it dimensions unstable.
‘A Sub-Zero Treatment’ has been devised to reduce the retained Austenite in hardened steel. It consists in cooling the metal to Sub Zero Temperature. This treatment is suitable only when the temperature at which the Martensite transformation is completed is below Zero. This transforms the retained austenite into Martensite. This increases the hardness of the part and its dimensions will become more stable.
Sub Zero Treatment is most frequently used for HSS tools, measuring tools and also for carburized gears and other mechanical components.
- Improved stress relief
- Better dimensional stability
- More uniform structural stability
- Improved wear resistance
- Useful technique for shrink fitting