Microstructure and mechanical properties of Fe–30Mn–9Al–C–3Ni low-density steel manufactured by selective laser melting

Low-density Fe–Mn–Al–C steels are widely used in the automotive and aerospace industries as advanced lightweight materials. In this study, highly spherical Fe–30Mn–9Al–C–3Ni powder with a narrow particle-size distribution, low oxygen content, and good flowability was prepared using the plasma rotating electrode process (PREP). Furthermore, Fe–30Mn–9Al–C–3Ni low-density alloy steel was manufactured for the first time using the selective laser melting (SLM) molding technique. Laser power was found to significantly impact the microstructure and mechanical properties of SLM-printed Fe–30Mn–9Al–C–3Ni alloys. The Fe–30Mn–9Al–C–3Ni alloy prepared at a laser power of 110 W (denoted as P-110) exhibited the best mechanical properties, including a yield strength of 887.1 MPa, tensile strength of 1076.8 MPa, elongation of 40.80%, and a maximum hardness value of 294 HV. This study highlights the potential of SLM molding for fabricating low-density Fe–Mn–Al–C steels with complex geometrical shapes and outstanding comprehensive mechanical properties.