The strain rate sensitive flow stresses and constitutive equations of a selective-laser-melt and an annealed-rolled 316L stainless steel: A comparative study

The strain rate dependent compressive flow stresses of a Selective-Laser-Melt 316L (SLM-316L) alloy and commercial (annealed-extruded) (C-316L) were determined, for comparison, between 1x10-4 ∼2500 s-1 ∼2800 s-1, respectively. Johnson Cook stress material model parameters both alloys also determined. microstructural examinations the deformed cross-sections tested specimens (interrupted tests) showed twinning-induced-plasticity in SLM-316L martensitic transformation-induced-plasticity C-316L alloy. Twin martensite formations detected microscopically higher dynamically until about 0.22 strain, while twin decreased at increasing strains due to adiabatic heating. sensitivity was determined slightly than that within quasi-static range (1x10-4 1x10-2 s-1), sensitivities similar quasi-static-high ∼2500-2800 s-1) low strains. A more rapid decrease found range. activation volumes alloys, corresponding dislocation intersections, indicated thermally activated deformation process involvement alloys.