Development in high-grade dual phase steels with low C and Si design
Tóm tắt
Cold rolled dual phase steels with low C and Si addition were investigated in terms of combination of composition and processing in order to improve mechanical properties and workability including welding and galvanizing. Mo and Cr could be used as alloying elements to partially replace C and Si to assure enough hardening ability of the steels and also give solute-hardening. Mo addition is more effective than Cr addition in terms of obtaining the required volume fraction of martensite and mechanical strength. The ferrite grain was effectively refined by addition of Nb microalloying, which gives optimized mechanical properties. The experimental results show that it is possible to obtain the required mechanical properties of high grade 800 MPa dual phase steel, i.e., tensile strength > 780 MPa, elongation > 15%, and yield/tensile strength ratio < 0.6 in the condition of low carbon (C < 0.11 wt.%) and low silicon design (Si < 0.05 wt.%) through adequate combination of composition and processing.
Tài liệu tham khảo
Hayami S, Frukawa F. Dual phase and trip steels. In: Proceedings of Microalloying 75, Union Carbide, New York, 1975, 311–321
Flaxa V, Shaw J. Material applications in ULSAB-AVC (advanced vehicle concepts). In: International Body Engineering Conference and Exhibition, Paris, France, 2002
Steven E. Review of the state of development of advanced vehicle control systems (AVCS). Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility, 1995, 24(6): 551–595
Debanshu B. Developments in advanced high strength steels. Iron & Steel (Supplement), 2005, 40: 69–75
Zhang Z, Song R, Cheng Z, et al. Research on processing microstructures and properties of 800 MPa cold rolling dual phase steel. Shanghai Metals, 2007, 9(5): 160–163 (in Chinese)
Zhang F, Song R, Liu Y. Research on heat treatment process and properties of 1000 MPa cold rolling dual phase steel. Hot Working Technology, 2008, 37(4): 42–45
Ma X, Tang D, Liu R. Effect of annealing and over-aging temperatures on the microstructure and properties of DP800 coldrolled steel. New Technology & New Process, 2008, 9: 53–56
Huppi G S. An evaluation of the importance of epitaxial ferrite in dual-phase steel microstructures. Scripta Metallurgica, 1980, 14: 1239–1243