Fatigue strength improvement of additively manufactured 316L stainless steel with high porosity through preloading

TY - JOUR

T1 - Fatigue strength improvement of additively manufactured 316L stainless steel with high porosity through preloading

AU - Subasic, Mustafa

AU - Olsson, Mårten

AU - Dadbakhsh, Sasan

AU - Zhao, Xiaoyu

AU - Krakhmale, Pavel

AU - Mansour, Rami

PY - 2024/3

Y1 - 2024/3

N2 - This work investigates the influence of a single tensile preload, applied prior to fatigue testing, on the fatigue strength of 316L stainless steel parts manufactured using laser-based powder bed fusion (PBF-LB) with a porosity of up to 4 %. The specimens were produced in both the horizontal and vertical build directions and were optionally preloaded to 85 % and 110 % of the yield strength before conducting the fatigue tests. The results indicate a clear tendency of improved fatigue life and fatigue limit with increasing overload in both cases. The fatigue limits increased by 25.8 % and 24.6 % for the horizontally and vertically built specimens, respectively. Extensive modelling and experiments confirmed that there was no significant alteration in the shape and size of the porosity before and after preloading. Therefore, the observed enhancement in fatigue performance was primarily attributed to the imposed local compressive residual stresses around the defects.

AB - This work investigates the influence of a single tensile preload, applied prior to fatigue testing, on the fatigue strength of 316L stainless steel parts manufactured using laser-based powder bed fusion (PBF-LB) with a porosity of up to 4 %. The specimens were produced in both the horizontal and vertical build directions and were optionally preloaded to 85 % and 110 % of the yield strength before conducting the fatigue tests. The results indicate a clear tendency of improved fatigue life and fatigue limit with increasing overload in both cases. The fatigue limits increased by 25.8 % and 24.6 % for the horizontally and vertically built specimens, respectively. Extensive modelling and experiments confirmed that there was no significant alteration in the shape and size of the porosity before and after preloading. Therefore, the observed enhancement in fatigue performance was primarily attributed to the imposed local compressive residual stresses around the defects.

KW - 316L stainless steel

KW - Defects

KW - Fatigue strength

KW - Overload

KW - PBF-LB

KW - Porosity

KW - Preload

UR - http://www.scopus.com/inward/record.url?scp=85181121906&partnerID=8YFLogxK

U2 - 10.1016/j.ijfatigue.2023.108077

DO - 10.1016/j.ijfatigue.2023.108077

M3 - Journal article

SN - 0142-1123

VL - 180

JO - International Journal of Fatigue

JF - International Journal of Fatigue

M1 - 108077

ER -