Processing of High‐Carbon Steel by Selective Electron Beam Melting

Abstract

In addition to the production of lost moulds, additive manufacturing (AM) is increasingly used for the direct manufacture of tools, inserts, or parts thereof. Depending on the material and tool geometry, the combination of additive and conventional technologies (hybrid production) are advantageous. Commercially available AM tool inserts have their limits on the kinds of the materials that can be used. High‐carbon, particle‐reinforced, or crack‐prone materials are indispensable for many areas of tool making but so far can hardly be processed using the common laser‐based AM methods, as rapid solidification in these brittle materials results in high residual stresses, which may lead to crack formation. In contrast, selective electron beam melting (SEBM) is working under elevated temperatures of up to 1100 °C and, thus, minimizes thermal stresses. This study shows how such materials can be processed by SEBM. Results are presented for the first‐time production of high‐carbon iron–chromium alloy. Herein, powder properties and their reusability are focused upon, as well as process parameters and their influence on part quality. Investigations on density, microstructure, and hardness are shown to illustrate the potential of the SEBM process. Final heat treatments reveal that a further increase in hardness is possible in this alloy.