The processing conditions during laser powder bed fusion (L-PBF) result in a limited range of materials to be manufactured without undesired cracking. The restricted material spectrum severely limits the potential product range. Within this context, the most utilized hardened and tempered steel is 42CrMo4, which possesses an increased hot-cracking susceptibility when processed via L-PBF.  To reduce or eliminate hot cracking in 42CrMo4 processed parts, a grain refinement by insitu precipitated TiN during gas atomization is provoked.
Within the presentation, experimental results are shown, demonstrating the difference between unmodified and TiN-modified 42CrMo4 specimens processed via L-PBF. The microstructural findings include scanning and transmission electron microscopy. Moreover, the mechanical results cover hardness as well as tensile tests.