Flame HardeningFlame hardening is used to prolong the life of wear faces of ferrous materials. The process relies on heating the surface of the steel being to its upper critical temperature between 780 and 900°C and then rapidly quenching. Flame hardening is a precision hardening process aimed at hardening only specific areas of a component, such as the teeth on a gear, rather than the entire component. To be hardened satisfactorily the steels must contain between 0.35% - 0.8% carbon. Steels components such as blades, pulleys and gear teeth can be made to last much longer when surface hardened, and component will stand an impact loads better if the core is still soft. Hardening burners have a row of holes or jets to cover the width and shape of work. Special burners can be made to match uneven profiles such as gear teeth. When the surface of the steel is heated to the required temperature water flows onto the work from holes behind the heating jets, quenching the steel thus hardening it to the required depth.
|
