Magnetization mechanisms for the non-destructive evaluation of early-stage thermal oxidation (corrosion) in low-carbon steels

Low-carbon steel undergoes corrosion during its service life, bringing about failures and substantial financial losses. Magnetic non-destructive testing techniques are used to assess changes occurring on the surface and subsurface when subjected to highly corrosive environments. In this work, magnetic responses including the magnetic hysteresis cycle (MHC), Magnetic Barkhausen Noise (MBN) and Magnetic Incremental Permeability (MIP) are measured at the early stage of corrosion to identify the technique and indicators with the most distinguishable response to changes in steel properties. The most responsive indicators are established through linear Pearson correlation coefficients comparing them with weight change and corrosion destructive observations.