Controlling Heat Treating Distortion by use of High Pressure Gas Quenching Methods

Heat treatment distortion when hardening or carburizing refers to changes in the size, shape, or geometry of a component that occur as a result of thermal processing. The material is subjected to heating and quenching cycles, which cause thermal and material transformation stresses that lead to distortion. The severity and type of distortion depends on various factors, such as the type of material, the heating and cooling rates, the temperature and duration of the treatment, and the design of the component. Distortion affects dimensional accuracy, surface finish, and mechanical properties of the material, and may require corrective measures such as post-treatment machining or reshaping.

Quenching in a highly agitated or aggressive quenching medium, such as water, brine, or oil, can cause significant distortion, such as warping, cracking, or distortion of holes. This paper, in contrast, will discuss using high pressure gas quenching (HPGQ) in a furnace provides a control the severity of the quench and the component is not subjected to a vapor blanket while quenching. Additionally, it will highlight new developments in HPGQ technology, such as individual gas quenching, that introduces a high level of control in the cooling rates a component is subjected to, thus reducing distortion.