Realization of Soft Magnetic Properties in Precipitation Hardening Stainless Steel

A precipitation hardening type soft magnetic stainless steel that has both workability (at low hardness during machining process) and durability (at high hardness during practical use) while maintaining good soft magnetic properties was developed. Precipitation strengthening by NiAl intermetallic compound shows the highest hardness after aging treatment at 550°C, and soft magnetic properties are obtained for compositions in the single phase of ferrite ( δ; bcc structure) region on the Schaeffler diagram. The compositional design of precipitation-hardenable soft-magnetic stainless steels was made possible by using the parameter obtained from the δ limit line in Schaeffler diagram for the microstructure and magnetic properties. And also by using the parameter obtained from the contribution of solution strengthening elements to material strength, the compositional design for hardness after solution treatment and aging treatment was made possible.