Piezomagnetic reversal behavior of anisotropic wire arc additively manufactured steel under tensile stress

In this research, the piezomagnetic reversal behavior of anisotropic steel under tensile stress in different directions was investigated. Tensile tests were performed on wire and arc additively manufactured (WAAM) steel specimens with varying orientations relative to the deposition direction, using a stepwise loading protocol. Magnetic field signals on the surfaces of both smooth and defective specimens under different loads were recordedwith a TSC-2 M-8 magnetometer. The distribution of the piezomagnetic field and its evolution with increasing load w-ere analyzed. Results demonstrate that piezomagnetic signals can be used to identify defects, while the presence of defects significantly alters the distribution of piezomagnetic signals in smooth regions. A comparative study of piezomagnetic signal differences among specimens with different orientations confirmed the anisotropy of piezomagnetic properties. Furthermore, the microscopic mechanism underlying the anisotropic evolution of the piezomagnetic field was discussed. It was found that characteristic parameters quantifying piezomagnetic properties exhibit a strong linear correlation with WAAM steel orientation. Notably, during incremental loading, the relationship between characteristic parameters and specimen directionunderwent a reversal. These findings advance the understanding of piezomagnetic behavior in additively manufactured steel and demonstrate potential for piezomagnetism-based stress assessment and defect detection applications.