ELECTROMAGNETIC QUALITY-CONTROL OF CARBURIZATION OF STEEL PRODUCTS

We have studied the effect that the casehardening (carburizing) temper ature and time, carburizer activity, and variation of the conditions o f subsequent heat treatment has on the electromagnetic properties of c arburized specimens of 12Kh2N4A steel. The possibilities of nondestruc tive testing for the main parameters that determine the quality of car burization of 12Kh2N4A steel products, using coercimetric and eddy-cur rent methods, are considered. The optimal depth of penetration of the magnetic flux in the portion of the inspected carburized product for g reater inspection reliability is determined. The joint use of the coer cimetric and eddy-current methods makes it possible to monitor the dep th and wear resistance of the carburized case and also to estimate the amount of retained austenite in the layer and reveal the effect of th e decarburized surface zone.