Uniform Elongation and the Stress-Strain Flow Curve of Steels Calculated from Hardness Using Empirical Correlations

An empirical relationship between the hardness and uniform elongation of non-austenitic hypoeutectoid steels has been developed. This new hardness-elongation relationship was combined with previously developed correlations of hardness and strength (yield and ultimate tensile strength) to predict the stress-strain flow curve from a single hardness test. The current study considers both power law hardening behavior and exponential hardening behavior. Reasonable agreement was observed between the experimental and predicted flow curves of a high strength, low alloy steel. Additionally, an empirical correlation of the flow strength at instability with hardness is provided.