Formation of deformation induced martensite in fatigued 316L steels manufactured by selective laser melting (SLM)

Destabilization of originally fully austenitic structure and formation of DIM (deformation induced martensite) were studied in SLMed 316L steels fabricated using different manufacturing systems and fatigued at room temperature in as-built state in two laboratories (TU Kaiserslautern and IPM Brno). Several microscopic techniques were adopted to reveal the distribution and morphology of DIM in the volume of fatigued steels. Results of microstructure investigations are confronted with the ferritescope measurements taken at different locations of fatigued specimens. Some factors which may impact the DIM formation in fatigued SLMed 316L steel are discussed.