Effects of Over-Aging Temperatures on Microstructure and Mechanical Properties of Low Cost Cold Rolled Dual Phase Steels
Author(s): LIU Ji-yuan, LUO Zong-an, SHI Ming-hao, ZHU Fu-xian, State Key Laboratory of Rolling and Automation, Northeastern University
Pages: 375-378
Year: 2014 Issue: 3
Journal: Journal of Northeastern University(Natural Science)
Keyword: dual phase steels; low cost; continuous anneal; over-aging temperature; microstructure and mechanical properties;
Abstract: A high strength and ductility dual phase steel was developed from the traditional steel via establishing reasonable processing parameter w indow s,w hich transferred from low to high additional values. The continuous annealing specimen w as prepared from C-Mn steels by hot and cold rolling. The microstructure contained ferrite and martensite w as obtained by the intercritical anneal,controlled cooling and the subsequent different over-aging procedures. The bainite transformation w as avoided w hen the over-aging temperature w as low er than 320 ℃. The volume fraction of the martensite increased w ith the decrease of temperatures. The tensile strength w as proportional to the volume fraction of the martensites,w hereas the yield strength and elongation performanced an inverse relationship. The strength-ductility balance w as 18 254. 6 MPa% in the 320 ℃ over-aging procedure as a better mechanical property.
Pages: 375-378
Year: 2014 Issue: 3
Journal: Journal of Northeastern University(Natural Science)
Keyword: dual phase steels; low cost; continuous anneal; over-aging temperature; microstructure and mechanical properties;
Abstract: A high strength and ductility dual phase steel was developed from the traditional steel via establishing reasonable processing parameter w indow s,w hich transferred from low to high additional values. The continuous annealing specimen w as prepared from C-Mn steels by hot and cold rolling. The microstructure contained ferrite and martensite w as obtained by the intercritical anneal,controlled cooling and the subsequent different over-aging procedures. The bainite transformation w as avoided w hen the over-aging temperature w as low er than 320 ℃. The volume fraction of the martensite increased w ith the decrease of temperatures. The tensile strength w as proportional to the volume fraction of the martensites,w hereas the yield strength and elongation performanced an inverse relationship. The strength-ductility balance w as 18 254. 6 MPa% in the 320 ℃ over-aging procedure as a better mechanical property.
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