Abstract：Through chemical composition design and TMCP process control, the effects of different strengthening mechanisms on the yield ratio of high strength Q500qE bridge steel were studied. The result indicated that the yield ratio was effectively lowered by increasing the content of solid solution elements such as Mn and Cr and decreasing the content of precipitation element Nb. Grain refinement was beneficial to the improvement of strength and toughness, but it is detrimental to the yield ratio. In comparison, transformation strengthening was found to be the best way to achieve high strength and low yield ratio. A dual-phase microstructure of ferrite plus bainite could be generated by an interrupted cooling process after hot rolling. The yield ratio could be effectively controlled by adjusting the proportion and hardness of ferrite and bainite phases.
武凤娟, 杨浩, 曲锦波. 强化机制对高强度桥梁钢Q500qE屈强比的影响[J]. 中国冶金, 2020, 30(12): 52-58.
WU Feng-juan, YANG Hao, QU Jin-bo. Effect of strengthening mechanism on yield ratio of high strength Q500qE bridge steel[J]. China Metallurgy, 2020, 30(12): 52-58.
2020, Vol. 30 
