Estimation of mechanical strength for pre-strained 316L austenitic stainless steel by small punch test

Finite Element Analysis on the Temperature- Dependent Burst Behavior of Domed 316L Austenitic Stainless Steel Rupture Disc

“…In the case of 300 K, one could observe some parabolic (elongated) dimples and cleavage features besides equiaxed dimples near the inner surface, as marked by the yellow arrows in Figure 4a. Such features were different from the full equiaxed dimples obtained during the conventional uniaxial tensile tests [21,22] and the small punch tests (SPT) [23,24]. It could be inferred that the severe plastic deformation was first initiated by the rapid tearing stress from the outside surface, and then the final fracture changed to an opening mode caused by the direct stress.…”

Deviations in yield and ultimate tensile strength estimation with the Small Punch Test: Numerical analysis of pre-straining and Bauschinger effect influence

“…It also shows the correlation equations previously obtained for other hypothetical materials (Table 4). Cuesta et al (Cuesta & Alegre, 2012) and Peng et al (Peng et al, 2019) pointed out empirically that pre-strained materials considerably differed from the correlation equations deduced for non-pre-strained materials, showing a greater slope in their correlation. It is worth noting that these differences were more pronounced for the application of the t/10 offset method and less accentuated for the optimized t/10 offset method, being the Mao's and CEN's methods in intermediate positions.…”

“…It was noted that simulations with pre-straining go from locations closed to correlation tendency of materials with n = 10 to the linear tendency of materials without hardening capability (n = ∞). Thus, changes in the correlation coefficients originated by pre-straining (and mentioned in different empirical studies (Cuesta & Alegre, 2012;Peng et al, 2019)) would come from dependency of the correlation methods not just with yield strength, but also with the strain-hardening capability. Considering that the optimized t/10 offset method was designed considering this dual dependency with the strain-hardening coefficient, which is the reason why this correlation method was the one that best estimated yield strength in this study.…”

“…After this first study, which analyzed the influence of the pre-straining in a material with a purely kinematic model (a very pronounced Bauschinger effect), a set of simulations with pre-straining were performed with an isotropic hardening model following the Ramberg-Osgood law and with the mechanical properties included in Table 1. The aim was to give an explanation to the observed behavior in the empirical investigations of Cuesta et al (Cuesta & Alegre, 2012) and Peng et al (Peng et al, 2019). Five simulations of the SPT were performed with tensile pre-straining levels of 0, 1, 3, 5 and 10% in the y-axis.…”

“…It is for this reason that the correlation coefficients were recalculated based on these pre-strained specimens. Peng et al (Peng et al, 2019) carried out a similar study with a stainless Steel AISI 360L. They tested tensile and SPT specimens of annealed material without pre-straining and with different prestraining levels (tensile pre-straining of 5% and 10%).…”