Effect of Post-Process Machining on Surface Properties of Additively Manufactured H13 Tool Steel

The tool steel AISI H13 is characterized by a high wear resistance and a good thermal shock resistance. H13 is mainly employed in applications such as tools for pressure die casting and forging. Processing of H13 by additive manufacturing techniques, such as selective laser melting (SLM), opens up new design possibilities with respect to e.g. internal cooling channels, in order to improve the tool performance during operation. However, due to high surface roughness and insufficient geometric accuracy imposed by SLM, additional cutting or forming processes are often required leading to an alteration of the surface and subsurface properties of the part. The presented work reveals the effect of SLM processing and subsequent face milling and/or deep rolling operations on the development of surface and subsurface properties and highlights adequate process windows.