Austenitic stainless steels are widely used in a large number of fields such as energy, petroleum chemistry and biological engineering, due to their good plasticity, nonmagnetic property, biological interchangeability and anticorrosion. Now, austenitic stainless steels account for 70% of the production and application of stainless steels. The recent increase in demand for nickel chrome austenitic stainless steel is depleting nickel resources year by year.
Many researchers made efforts to use cheap elements instead of nickel. Addition of nitrogen element to austenitic stainless steels can raise the strength of austenitic stainless steels and stabilize the austenitic structure.
The Cr17Mn17Mo3NiN steel is a typical low nickel austenitic stainless steel where Mn, Mo and N are used instead of Ni. The Cr17Mn17Mo3NiN steel has improved strength, plasticity and local corrosion resistance.
Accurate prediction of the flow stress of Cr17Mn17Mo3NiN low nickel austenitic stainless steel in hot working processes is of primary importance in economizing the material for new austenitic stainless steel, designing rational hot working processes such as hot rolling and forging, and increasing the processing efficiency.
Jang Kun Song, a student at the Faculty of Material Science and Technology, proposed phenomenological and physical-based constitutive models for the Cr17Mn17Mo3NiN low nickel stainless steel, based on the true stress-strain curves acquired from isothermal uniaxial compression tests, and estimated and compared the prediction accuracy of the proposed constitutive models.
As a result, the flow stresses predicted by the newly modified Johnson-Cook model and the microstructural-based constitutive model were in good consistent with the experimental results. Especially, the prediction accuracy of the microstructural-based constitutive model was the highest.
For more information, you can refer to his paper “Comparison of phenomenological and physical-based constitutive material models for Cr17Mn17Mo3NiN low nickel stainless steel” in “Materials Research Express” (SCI).