Magnetic properties of as-built and heat treated M789 and M300 maraging steels produced via laser powder bed fusion

This paper reports on the magnetic characteristics of maraging steels additively produced through laser powder bed fusion with a focus on two specific grades, namely M789 and M300. Magnetic material properties, including magnetization curve, magnetic hysteresis, and loss, are systematically examined for both grades. The effect of a solution annealing plus aging heat treatment is explored to determine how these properties differ between the asbuilt and heat-treated conditions. The findings illustrate a substantial improvement in magnetic properties postheat treatment. Specifically, an increase in maximum magnetic permeability by 73 % for M789 and 56 % for M300 is measured. Additionally, reductions in hysteresis loss were observed, with a decrease of 29 % for M300 and 35 % for M789. The knowledge of these properties will be crucial for applying additive manufacturing on high-speed rotors, magnetic gears or magnetic bearings components where maraging steels are already, sometimes, utilized.