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
Influence of coiling temperature on microstructure and mechanical properties of a hot-rolled high-strength steel microalloyed with Ti, Mo and V
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
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 °C, 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%.
Abstract: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 °C, 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%.
Zhi-xiang Fu,Geng-wei Yang,Ru-yang Han, et al. Influence of coiling temperature on microstructure and mechanical properties of a hot-rolled high-strength steel microalloyed with Ti, Mo and V[J]. Journal of Iron and Steel Research International, 2022, 29(3): 484-493.