Gleeble热模拟试验表明,低碳Mn系贝氏体钢随着变形温度降低,仿晶界铁素体和粒状贝氏体都发生了细化,冲击韧性显著提高。加Nb后的Mn系贝氏体钢在相同工艺下组织得到了进一步细化。实验室试轧数据表明,含Nb的Mn系贝氏体钢降低终轧温度后,韧性提高的幅度比不含Nb钢更大,工业化前景广阔。 Gleeble thermal simulation tests show that as the deformation temperature decreases, both the grain boundary ferrite and granular bainite have been refined and the impact toughness has been significantly improved. After adding Nb Mn bainitic steels in the same process the organization has been further refined. Laboratory test rolling data show that, Nb-containing bainitic steels reduce the finish rolling temperature, the toughness increases more than the non-Nb steel, industrialization prospects.