Analysis of austenitic stainless steels (AISI 303 and AISI 316Ti) regarding crack driving forces and creep responses

摘要

Two types of austenitic stainless steels, AISI 303 and AISI 316Ti, were investigated experimentally and numerically in this paper in order to determine some of the material characteristics important for material selection in engineering design process. Ultimate tensile strength, yield strength, and modulus of elasticity for room and selected elevated temperatures have been experimentally obtained. Improved heat resistance of AISI 316Ti can be noticed when comparing yield and tensile strength values of mentioned materials. Also, a comparison of material creep responses for selected temperatures and stress levels is presented. It can be noticed that at the same relative stress level AISI 303 exhibits higher strain percentage than AISI 316Ti. Also, as the temperature rises, AISI 316Ti holds stable strain percentage growth when compared to AISI 303. In addition, a numerical procedure of determining crack driving force is performed using J-integral as a measure. Obtained J values are plotted versus specimen crack growth size (Delta a) for different specimen geometries (a/W) and for different specimen types. Higher resulting values of J-integral for AISI 303 than AISI 316Ti can be noted. Although this procedure differs from experimental analysis, results can be useful as fracture parameter in fracture toughness assessment.