Stress assessment from magnetic measurements

Residual stresses play a pivotal role in determining the performance, integrity, and service life of structural steels Residual stresses are usually analysed by X-Ray diffraction. This technique may not be adapted for high-speed production, but the evaluation of internal stresses enables the anticipation of potential breakdown and degradation. Magnetic measurements are an alternative non-destructive technique, employed to characterize industrial components. The exploration of its ability to evaluate residual stresses is a promising line of research.

This study provides an investigation into the effects of tensile stress on the magneto-elastic behaviour of iron-silicon (FeSi) single crystals, highlighting the fundamental mechanisms governing their magnetization response. Four key experimental techniques were employed to explore these interactions: magnetization hysteresis loops Ba(Hsurf) to assess global magnetic response, magnetic Barkhausen noise MBNenergy(Hsurf) measurements to probe domain wall dynamics, incremental permeability MIP(Hsurf) measurement to probe domain wall bulking and magnetostriction measurements ε_µ(Hsurf), to quantify strain behaviour and magneto-elastic coupling under applied stress. By exploring new stress evaluation techniques, this study contributes to the development of more reliable and efficient diagnostic methods for monitoring the integrity of ferromagnetic components in production.