采用扫描电镜、透射电镜、金相显微镜、闪光焊接及力学性能测试,对铌微合金化和控冷工艺开发的HRB500钢筋微合金析出强化效果、控冷细晶强化效果、显微组织、焊接性能及时效性等进行了试验研究。结果表明:通过控制钢中铌含量(质量分数)为0.027%～0.035%及合适的轧制温度,Nb(CN)析出量占总铌量的75.67%,析出强化效果明显;钢筋控冷后上冷床温度控制在670～700℃,细晶强化效果明显,抗震性能好;钢筋具有低应变时效性及良好的焊接性能;生产成本和钒氮微合金化工艺相比降低75元/t,经济效益显著。 The microstructure and properties of HRB500 steel microalloyed by Nb microalloying and controlled cooling were studied by SEM, TEM, metallographic microscope, flash welding and mechanical properties test. And timeliness of the experimental study. The results show that the precipitation of Nb (CN) accounts for 75.67% of the total niobium by controlling the niobium content (mass fraction) in the steel from 0.027% to 0.035% and the suitable rolling temperature, and the precipitation strengthening effect is obvious. Cooling bed temperature control at 670 ~ 700 ℃, fine grain strengthening effect is obvious, good seismic performance; steel with low strain aging and good welding performance; production costs and vanadium-nitrogen micro-alloying process compared to reduce 75 yuan / t, the economy Benefit significantly.