Laser Powder Bed Fusion (PBF-LB/M) of austenitic 316L stainless steel generates steep thermal gradients and thus complex residual-stress fields that are critical for cryogenic and hydrogen applications. Surface stresses are typically tensile while the bulk is compressive and triaxial, with magnitudes governed by scanning strategy, interlayer time and heat accumulation. Deep cryogenic treatment of conventionally processed and hydrogen-resistant steels has been shown to relax internal residual stresses by about 50–60% via dislocation rearrangement and grain refinement, often without phase transformation. For PBF-LB/M 316L, however, this relaxation has neither been quantified nor described by a predictive simulation framework. a numerical model describing residual-stress evolution during repeated deep cryogenic cycles between room temperature, 77 K, and 4 K is established, with boundary conditions and validation data obtained from experiments performed in this study. A single PBF-LB/M parameter set is used to fabricate 316L specimens, whose initial residual stresses are characterized by X-ray diffraction at the surface and by the contour method for an internal plane normal stress field. Microstructure (grain morphology, texture, dislocation structures) and porosity are assessed by Electron Backscatter Diffraction, Transmission Electron Microscopy and serial X-ray micro-computed tomography. These data sets are used to calibrate and validate a thermo-elasto-plastic finite-element model with an internal variable describing stress relaxation during cryogenic cycling. The model is driven by measured residual-stress fields and thermal histories, and is constrained by the neutron- and XRD-derived triaxial strains. We use the model to predict how much of the PBF-LB/M-induced residual stress can be relaxed without phase transformation, and how this depends on the initial stress distribution and the cooling protocol. The results support residual-stress modelling of additively manufactured 316L during repeated cryogenic thermal cycling.