Design of Fully Austenitic Medium Manganese Steels

20th Chemnitz Seminar on Materials Engineering - 20. Werkstofftechnisches Kolloquium

Luan, G.^1 ; Volkova, O.^1 ; Mola, J.^1

Institute of Iron and Steel Technology, Technische Universität Bergakademie Freiberg, Leipziger St. 34, Freiberg

09599, Germany^1

关键词: Advanced high strength steel;    Austenitic microstructure;    Austenitization temperatures;    Ferritic microstructure;    Martensite start temperature;    Microstructural examination;    Third generation;    Twinning induced plasticity steels;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/373/1/012002/pdf
DOI  :  10.1088/1757-899X/373/1/012002

来源: IOP

【 摘 要 】

Due to their higher ferrite potential compared to high Mn twinning-induced plasticity (TWIP) steels, medium Mn steels usually exhibit austenitic-ferritic microstructures, which makes them suitable for third-generation advanced high-strength steel applications. Nevertheless, the strain hardening characteristics of medium Mn steels are inferior to those of fully austenitic high Mn steels. The present work introduces alloy design strategies to obtain fully austenitic medium Mn steels capable of the TWIP effect. To achieve a fully austenitic microstructure, the martensite start temperature is reduced by raising the C concentration to above 1 mass-%, which in turn facilitates the formation of cementite. The formation of cementite during cooling from austenitization temperature is counteracted by alloying with Al. Microstructural examination of slowly-cooled Fe-Mn-Al-C and Fe-Mn-C steels indicated that Al changes the morphology of intergranular cementite from plate-shaped to equiaxed.