Effect of laser‐scan strategy on microstructure and fatigue properties of 316L additively manufactured stainless steel
Abstract
The particular roles of grain morphology and defects, controlled using laser-scan strategies, on the mechanical properties and the fatigue behavior of 316Lstainless steel are investigated. Microstructural characterization and X-raytomography analysis was performed to understand the genesis of polycrystal-line microstructure and defects. Tensile and fatigue tests were performed toanalyze the effect of defect population and microstructural properties on plas-ticity and damage mechanisms during monotonic and cyclic loading. Theeffect of the grain-size and shape and type of defect was carefully investigatedto evaluate the mechanisms driving the mechanical behavior under quasi-static and fatigue loading. It is shown that the laser-scan strategy determinesthe anisotropy in the plane perpendicular to the building direction. Moreover,contrary to the existing literature, for 316L obtained by AM, the grain size andshape does not affect the mechanical properties, and LoF defects drive thefatigue life, independent of the defect/grain size ratio.