Influence of coiling temperature on microstructure and mechanical properties of a hot-rolled high-strength steel microalloyed with Ti,Mo and V  

作　　者：Zhi-xiang Fu Geng-wei Yang Ru-yang Han Yao-wen Xu Xin-ping Mao Si-qian Bao Gang Zhao 

机构地区：[1]Hubei Provincial Key Laboratory for New Processes of Iron Making and Steel Making,Wuhan University of Science and Technology,Wuhan,430081,Hubei,China [2]The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan,430081,Hubei,China [3]Collaborative Innovation Center of Steel Technology,University of Science and Technology Beijing,Beijing,100083,China

出　　处：《Journal of Iron and Steel Research International》2022年第3期484-493,共10页

基　　金：supported by the National Key R&D Program of China(No.2017 YFB0305100);the Key Research and Development Program of Hubei Province(No.2020BAB057);the Natural Science Foundation and Major Technology Innovation of Hubei Province(No.2017AAA113).

摘　　要：Influence of coiling temperature(CT)on the microstructure and mechanical properties of a hot-rolled high-strength steel microalloyed with Ti,Mo and V was elucidated.The precipitation behavior of nano-sized particles was investigated by theoretical calculation and quantitative analysis.And the results revealed that V-enriched(Ti,Mo,V)C precipitated in the ferrite matrix.As the CT decreased,the site fractions of Ti in(Ti,Mo,V)C changed little,the site fractions of Mo increased,and the site fractions of V decreased accordingly.Moreover,the low CT could refine the microstructure and precipitated particles but suppress the precipitation of(Ti,Mo,V)C particles simultaneously,leading to the volume fraction of(Ti,Mo,V)C significantly decreasing,consequently causing an increment of grain refinement strengthening and a reduction in precipitation hardening.When the CT was 600℃,the steel characterized by fine polygonal ferrite,a small amount of bainite and nano-sized(Ti,Mo,V)C precipitates exhibited the optimum mechanical properties with the ultimate tensile strength of 870 MPa,yield strength of 807 MPa and elongation to fracture of 17%.

关 键 词：Ti-Mo-V complex microalloying Coiling temperature PRECIPITATION Strengthening mechanism Microstructure 

分 类 号：TG13[一般工业技术—材料科学与工程]