High performance steels produced by Selective Laser Melting

By an appropriate alloy design, steels with high strength, hardness, wear and corrosion resistance as well as an adequate toughness can be processed via selective laser melting (SLM). This results from a significant refinement of the grains and microstructural constituents as well as extended solid solubility and reduction of quantity and size of phase segregations caused by the rapid solidification during the process.

For a novel developed Fe85Cr4Mo8V1C1 tool steel, non-equilibrium segregation leads to an orderly phase arrangement of complex nanoscale carbides at the boundary of the dendrites surrounded by retained austenite and martensitic matrix. Due to this combination of phases and appropriate morphology, excellent mechanical properties, like a high compressive strength of over 5000 MPa combined with a fracture strain of about 16 % can be obtained without any post-treatment, which presents a significant increase in strength in comparison to the as-cast counterpart. Furthermore, the hardness and wear resistance can be enhanced by processing high performance tool steels via SLM.

These findings show the high potential of processing tailored steels by SLM for high performance applications.