Abstract
Through DOE (design of experiment), ЕТ (eddy current testing) is included and proven as a quality indicator of carburizing, quenching and tempering of hydraulic motor parts.A method is suggested for calibrating NDT (non-destructive testing) by means of combined representation of regression models in the field of the technological factors of heat treatment and contour control charts.A method is presented here for choosing the working frequency for ET.It is also suggested that experimental design be considered a basic building element in the methodology of carburized parts ET.This article also presents a methodology for conducting eddy current testing in industrial settings.