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采用膨胀法结合金相分析建立微合金低碳Ｍｎ－Ｂ钢的动态ＣＣＴ曲线，在二辊实验轧机和控冷设备上模拟热连轧、快速冷却及卷取工艺。实验结果表明：变形后以１０～２５℃／ｓ的速度冷却，获得针状铁素体（ＡＦ）＋多边形铁素体（ＰＦ）组织。轧后以平均冷速８℃／ｓ快冷至６２０℃装炉缓冷模拟卷取，抗拉强度达到４９０ＭＰａ，显微组织由多边形铁素体＋针状铁素体和少量珠光体构成，具有良好的冷成形性和较低的屈强比。
The dynamic CCT curves of microalloyed low carbon Mn-B steels were established by the expansion method and the metallographic analysis. The hot rolling, rapid cooling and coiling were simulated on the two-roll experimental rolling mill and controlled cooling equipment. The experimental results show that acicular ferrite (AF) + polygonal ferrite (PF) structure is obtained after being deformed by cooling at 10-25 ℃ / s. After cooling with an average cooling rate of 8 ℃ / s fast cooling to 620 ℃ loading slow cooling simulated coiling, the tensile strength of 490MPa, the microstructure of polygonal ferrite + acicular ferrite and a small amount of pearlite composition, with Good cold formability and low yield ratio.