Prediction of the yield strength of a secondary-hardening steel

Based on detailed three-dimensional (3-D) local-electrode atom-probe (LEAP) tomographic measurements of the properties of Cu and M2C precipitates, the yield strength of a high-toughness secondary-hardening steel, BA160, as a function of aging time is predicted using a newly developed 3-D yield strength model. Contributions from each strengthening constituent are evaluated with the model, and superposition laws are applied to add each contribution. Prediction of the yield strength based entirely on 3-D microstructural information is thus achieved. The accuracy of the prediction depends on the superposition laws and the LEAP tomographic measurements, especially the mean radius and volume fraction of M2C precipitates.