Size effect criteria on the small punch test for AISI 316L austenitic stainless steel

The miniature specimen test technique has been extensively studied for quantifying the properties of bulk materials with greatly reduced volume recently. In this paper small punch test (SPT) is used to evaluate effects of specimen thickness, grain size and thickness-to-grain size ratio (TGR) on mechanical properties of 25 samples of type 316L austenitic stainless steel with nearly the same crystallographic texture. Effective SPT yield and maximum loads were measured and correlated with yield and ultimate strengths of conventional tensile test. The results show that SPT is sensitive not only to grain size, but also to thickness and TGR. Size effects exist between SPT and standard-sized samples. The present work gives a size effect criterion of SPT for engineering application. In addition, the underlying mechanisms of these size effects are provided.