Magnetic Barkhausen emission analysis for assessment of microstructures and damage

This paper highlights the application of magnetic Barkhausen emission (MBE) analysis for assessment of microstructures and damage in various materials including carbon steel, Cr-Mo ferritic steels, 17-4 PH steel and metastable austenitic stainless steel. Thermally-induced microstructural changes in Cr-Mo steels have been correlated with MBE, based on a two-stage magnetisation process model. The MBE parameters have also been used to characterise different stages of tensile deformation and to assess tensile strength. Charpy impact energy, quality of induction hardening process, progress of carburisation in reformer tubes and fatigue damage.