Quantitative Evaluation of Metallurgical Mechanisms Affecting Strength of Austenitic Stainless Steels

Abstract

Relations predicting the mechanical properties of bars of austenitic stainless steels are already available, but no systematic work has been performed to predict the strength of cold rolled and annealed stainless steels. The tensile properties of a large number of cold rolled and annealed AISI 304 stainless steel are here correlated with their chemical composition and microstructure. Quantitative effects of various strengthening mechanisms such as grain size, δ-ferrite content and solid solution strengthening by both interstitial and substitutional solutes are described. Interstitial solutes have by far the greatest strengthening effect and, among the substitutional solutes, the ferrite-stabilizing elements have a greater effect than the austenitestabilizing elements. Regression equations are developed that predict with good accuracy the proof stress and tensile strength in AISI 304 stainless steels.