A comparative study of microstructure and high-temperature mechanical properties of 15-5 PH stainless steel processed via additive manufacturing and traditional manufacturing

In the present study, 15-5 PH Stainless Steel (SS) was produced via an additive manufacturing (AM) technique known as Direct Metal Laser Sintering (DMLS). The microstructure and mechanical properties of the AM alloy were compared with those of a traditionally manufactured (TM) or wrought 15-5 PH SS. Microstructural examination of both materials is performed by optical microscopy, transmission electron microscopy, and electron backscatter diffraction in a scanning electron microscope. A distinct difference was observed between the martensitic structure of the AM and TM alloys with the AM material with smaller grain sizes and round-shaped particles. The Vickers microhardness of the AM material was found to be greater than that of the TM material. Tensile testing at 593 °C exhibited a greater strength for the AM material compared to the TM material. Furthermore, the creep rupture life of the AM material was found to be greater compared to the TM material when tested at a temperature 593 °C and applied stress of 211 MPa. Fractographic examination of the crept and tensile specimens was conducted via scanning electron microscopy.