Influence of nitrogen addition on phase stability and mechanical properties of advanced medium-Mn steels

• Grant number: 23/08368-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2023
• End date: June 30, 2025
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Principal Investigator: Lucas Barcelos Otani
• Grantee: Hans Steinern Krystian Von Lang
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

Advanced high-strength steels (AHSS) are materials whose focus is on increasing the mechanical strength in order to enable a reduction in the thickness of sheets for structural applications. Among the distinct possible chemical compositions, medium and high-Mn steels stand out for presenting an excellent combination of ductility and mechanical strength. Most of the studies and potential applications focus on austenitic microstructure due to the fact that it can present induced plasticity mechanisms, such as the TRIP effect (Transformation Induced Plasticity) and the TWIP effect (Twinning Induced Plasticity). The effect of carbon is still under debate in the literature because recent studies indicate that there is the possibility of increase not only in ductility, but also in mechanical strength through the addition of this element. The main effect is on the Stacking Fault Energy (SFE), main property that describes the mechanical behavior of alloys with a face-centered cubic structure (FCC). Within this subject, it is noticed that there are few studies that evaluate the effect of nitrogen, both on the final microstructure and on the mechanical behavior. It is believed that this element can generate an effect similar to carbon, thus ensuring greater potential for alloy design and final properties. From all the above, the objective of this scientific initiation project is to study two compositions with different nitrogen contents, in order to verify its influence both in the formed phases after the thermomechanical processing, as well as in the final mechanical behavior via tensile test.