Metal additive manufacturing (AM) technologies are ideal for the fabrication of geometrical-complex tooling components. High-carbon steels are established for tooling applications, but not adapted to metal AM technologies, such as the widely used laser powder bed fusion (LPBF). Owing to the layer-by-layer fabrication, which is characteristic for any metal AM technology, feedstock is exposed to a series of rapid melting immediately followed by solidification at ultrahigh cooling rates. Thereby, repetitive and non-uniform cooling conditions with the heat being almost entirely extracted through the underlying material, cause the evolution of residual stresses within the AM-part. This behaviour can be further complicated by alloy-dependent solid phase transformations, such as the austenite-to-martensite transformation as it can occur for high-carbon tool steels.

Here, we present a high-carbon steel developed for LPBF which can be processed without additional base plate pre-heating. An in-depth characterization allows to explore the hierarchical microstructure. In addition to mechanical properties, the abrasive wear behaviour of the LPBF-fabricated components is studied and the appendant underlying mechanisms revealed. The mechanical and wear properties are compared to the commercially available 1.2379 tool steel which serves as reference.

(K. Kosiba et al., J. Mater. Sci. Technol. 156 (2023) 1–19)