中文摘要：

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。

英文摘要：

By adding a trace of niobium into B220P2, its influence on the microstructure and properties of hot rolling B220P2 was studied. The microstructure and mechanical properties of B220P2 with and without adding Nb were characterized by metallographic microscope, scanning electron microscope and tensile testing machine. The results show that, adding a trace of niobium into B220P2 can refine the crystalline grain markedly, delay the phase transition of pearlite and increase the tensile strength, yield strength,plastility and toughness of hot rolling B220P2.