Low Cycle Fatigue Behaviour of an AISI 316L Stainless Steel Additively Manufactured by Laser Powder Bed Fusion (L-PBF)

The present work deals with the mechanical testing of low-cycle fatigue (LCF) performance and cyclic plasticity response of an AISI 316L stainless steel, produced by laser-powder bed fusion (L-PBF). The outcome of this experimental investigation was compared with those obtained for a wrought AISI 316L steel. Both materials show a cyclic softening. Only for the wrought counterpart a secondary hardening appears. The fatigue life curves were estimated both by a strain-based (Manson-Coffin) and energy-based models. Manson-Coffin and energy-life model show distinct curves for L-PBF and wrought AISI 316L steel. A fractographic analysis on a broken specimen of L-PBF AISI 316L revealed porosities as crack nucleation sites.