Influence of Microstructure and Defects on Mechanical Properties of AISI H13 Manufactured by Electron Beam Powder Bed Fusion

Electron beam powder bed fusion (E-PBF) is a well-known additive manufacturing process. Components are realized based on layer-by-layer melting of metal powder. Due to the high degree of design freedom, additive manufacturing came into focus of tooling industry, especially for tools with sophisticated internal cooling channels. The present work focuses on the relationships between processing, microstructure evolution, chemical composition and mechanical properties of a high alloyed tool steel AISI H13 (1.2344, X40CrMoV5-1) processed by E-PBF. The specimens are free of cracks, however, lack of fusion defects are found upon use of non-optimized parameters finally affecting the mechanical properties detrimentally. Specimens built based on suitable parameters show a relatively fine grained bainitic/martensitic microstructure, finally resulting in a high ultimate strength and an even slightly higher failure strain compared to conventionally processed and heat treated AISI H13.

Automated summary

The study investigates the relationships between processing parameters, microstructure evolution, chemical composition, and mechanical properties of a high alloyed tool steel AISI H13 processed by E-PBF. Specimens without fusion defects but free of cracks show improved ultimate strength and failure strain when optimized processing parameters are used. The fine grained bainitic/martensitic microstructure obtained from suitable processing parameters leads to enhanced mechanical properties compared to conventionally processed AISI H13.