Comparison of Microstructure and Mechanical Properties of Additively Manufactured and Conventional Maraging Steel

Abstract

Maraging steel is an iron-nickel steel alloy, which achieves very good material properties like high toughness, hardness, good weldability, high strength and dimensional stability during heat treatment. In this work, maraging steel 18Ni-300 was manufactured by selective laser melting. It is a method of additive manufacturing (AM) technology, which produces prototypes and functional parts. Sample of additively manufactured and conventional steel with the same chemical composition were tested after in three different states – heat treated (as-built/as-received), solution annealed and precipitation hardened. Resulting microstructures were analysed by light and scanning electron microscopy and mechanical properties were obtained by hardness measurement and tensile test. Cellular martensitic microstructures were observed in additively manufactured samples and conventional maraging steel consisted of lath martensitic microstructures. Very similar mechanical properties were obtained for both steels after the application of the same heat treatment. Ultimate tensile strengths reached 839 – 900 MPa for samples without heat treatment and heat treated by solution annealing, the samples after precipitation hardening had tensile strengths of 1577 – 1711 MPa.

Microstructure-Properties Characterization of Selective Laser Melted Biomedical Co-28Cr-6Mo Alloy

“…Additive manufacturing is an alternative route of Co-28Cr-6Mo alloy fabrication [13]. Selective laser melting (SLM) (also known as Laser Powder Bed Fusion) is reported to be applied for a wide range of alloys including biomedical alloys [14 -16].…”