Heat Treatment (Heat Treating) : Alternate steps of controlled heating and cooling of materials for the purpose of changing physical or mechanical properties. (Spec 6A, Spec 16A).
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}