Mechanical Properties and Strain-Hardening Models of Supermartensitic Stainless Steels Alloyed to Nitrogen and Vanadium

This work presents a detailed study directed to supermartensitic stainless steels (SMSS) alloyed to nitrogen (UNS S41425) and vanadium (UNS S41427), showing comparison between them by varying their tempering temperature, evaluating the behavior in its mechanical properties, presenting a fractographic and microstructural analysis between these alloys, besides to demonstrate techniques for modeling these strain-hardening results with best coefficients that determine these materials with good predicted values. The Hollomon, Voce and Chaboche models were determined, using an iterative regression method (R²) in order to obtain the best coefficients for each analysis condition. This work concludes by presenting graphic results of the effect of tempering temperature increase on the final mechanical properties, evaluates the differences obtained between these materials and presents an evaluation of the behavior of each coefficient of the models presented separately, showing the best R² fitting results. With the models determined, it is possible to use the results in this work to perform numerical simulations and meet the needs of the engineering on industry.

Keywords:
Supermartensitic stainless steels; heat treatment; slow strain test; mechanical properties; modeling