Influence of scanning strategy on magnetic properties of 630 stainless steel fabricated by directed energy deposition method

We investigated how the scanning strategy (SS) influences the magnetic properties of ferromagnetic metal specimens additively manufactured using 630 stainless steel powder and a directed energy deposition machine. The magnetization curves were measured by using B and H coils and a magnetic flux meter. The specific saturation magnetization, coercivity, and specific magnetic susceptibility were calculated from the magnetization curves obtained. Moreover, the martensite fraction, magnetization structure, and martensite structure were measured and visualized using X-ray diffraction, the Bitter method, and electron backscatter diffraction, respectively. The magnetic properties and martensite fraction depended on the SS, and magnetic poles were generated in each sub-block structure. Furthermore, a numerical analysis using a magnetic micromechanics model indicated that the variation in the martensite structure due to the SS produced differences in the magnetic properties.