ausblenden:
Schlagwörter:
Alloyed steels; Partitioning step; Quenching-partitioning-tempering; Retained austenite; Ultimate tensile strength, Bainite; Elongation; Manganese; Martensitic steel; Mechanical properties; Microstructure; Quenching; Silicon; Tempering, Carbides
Zusammenfassung:
A novel quenching-partitioning-tempering (Q-P-T) process was employed in a Mn-Si-Cr alloyed steel to obtain a triplex microstructure comprising carbide-free bainite, martensite and retained austenite. The carbide-free bainite formed during the quenching step (rather than partitioning step) of Q-P-T process can enhance the mechanical properties (e.g. the product of strength and elongation, ~31.4. GPa) by extending the partitioning time up to 30. min. A good combination of strength and elongation (Ultimate tensile strength: ~1655. MPa; Elongation: ~19) has been realized for the Mn-Si-Cr alloyed high strength steel without expensive alloying, e.g. Ni, Mo, Nb in previous QP/Q-P-T processes. The enhanced mechanical properties could be attributed to the various types of retained austenite in the Q-P-T treated carbide-free bainite/martensite/austenite triplex microstructure. © 2012 Elsevier B.V.
