Magnetic hysteresis loop parameters and Barkhausen noise for microstructural characterisation of steels

Abstract

Characterization of microstructures by non-destructive test techniques are needed for assessment of heat treatment procedures and degradations in mechanical properties by service environment. Magnetic techniques based on the use of analysis of Barkhausen noise and hysteresis loop parameters form an important class of techniques for this purpose. This paper considers the microstructures in various kinds of steels such as 9Cr-1Mo steel, 2.25Cr-1Mo steel, and 17-4PH stainless steel. The paper explains the instrumentations and test parameters used and the correlation of the parameters with the microstuctural features.