Cavitation erosion resistance of 1.2709 alloy produced via Laser-Powder Bed Fusion

Abstract

Maraging steels, like 1.2709 (18Ni-300), are attractive materials for the aerospace, automotive, tooling, and bearing gear industries because of their high yield, tensile strength, and good toughness. The low-carbon martensite matrix and nanoscale intermetallic precipitates combine to provide distinctive mechanical properties. In particular, due to their low carbon content, these steels are easily weldable and are therefore appropriate for additive manufacturing (AM) processes like laser-based powder bed fusion (LPBF). The tooling and molding industry has just lately started using this fabrication technique to create inserts with conformal cooling channels that can extend the lifetime of the insert and core while boosting the cast quality. These parts are frequently exposed to high levels of stress, wear, and even aggressive conditions. In this context, this research focuses on a peculiar, and thus understudied, erosion phenomenon known as cavitation erosion. According to the ASTM G32 standard, the cavitation erosion resistance of 1.2709 maraging steel samples produced by additive manufacturing as well as by forging was investigated. Microstructural analyses were carried out to evaluate the effect of the different microstructures resulting from the different manufacturing techniques on erosion behavior. When compared to the forged maraging steel, the AM one shows less resistance to the initiation of the erosion phenomenon. Nevertheless, the wear rates of the two materials are comparable.