Title: Investigation of as-quenched and tempered commercial steels by Magnetic Barkhausen Noise method

Authors: C. Hakan Gur, ibrahim Cam

Addresses: Department of Metallurgical and Materials Engineering, Middle East Technical University, 06531 Ankara, Turkey. ' Central Lab., Middle East Technical University, 06531 Ankara, Turkey

Abstract: This study aims to characterise as-quenched and tempered steels by the Magnetic Barkhausen Noise method, and to contribute to optimisation of heat treatment processes. Identical austenitisation and quenching procedures were applied to SAE 1040 and SAE 4140 specimens to eliminate the effect of grain size. Samples were tempered at 200°C and 600°C for 2 hours. Microstructures were characterised by metallographic examinations and hardness measurements. Amplitude, position and frequency spectrum of signals were evaluated using a commercial system. As the tempering temperature increases, in contrast to the reduction in hardness, magnetic response increases due to the enhancement of domain wall displacement.

Keywords: steel components; quenching; tempering; microstructure; magnetic Barkhausen noise; MBN; heat treatment; austenitisation; metallography; hardness; temperature; magnetic response; domain wall displacement.

DOI: 10.1504/IJMMP.2006.010627

International Journal of Microstructure and Materials Properties, 2006 Vol.1 No.2, pp.208 - 218

Published online: 09 Aug 2006 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article