通过向B220P2中加入微量铌,研究了铌对B220P2热轧组织和性能的影响;利用金相显微镜、扫描电镜和拉伸试验机等设备,对含铌与不含铌的两种B220P2的热轧显微组织和力学性能进行了分析。结果表明,向B220P2中加入微量铌后可显著细化晶粒,推迟珠光体相变,增加了B220P2热轧板的抗拉强度、屈服强度和塑韧性。 By adding niobium to B220P2, the effect of niobium on the microstructure and properties of B220P2 hot-rolled was studied. The hot rolling of B220P2 with and without niobium was studied by means of metallographic microscope, scanning electron microscope and tensile testing machine. Microstructure and mechanical properties were analyzed. The results show that the addition of trace niobium to B220P2 can significantly refine the grain, postpone the pearlite transformation and increase the tensile strength, yield strength and ductility of B220P2 hot-rolled sheet.