Compared with Nb and V microalloyed steel, Ti microalloyed steel has the lowest cost, so a low-carbon Ti microalloyed hot roll strip steel has been designed. The microstructure and mechanical properties of the steels with different coiling temperature were investigated by utilizing SEM and TEM. The results show that the coiling temperature has a considerable influence on both the microstructure and mechanical properties. The microstructure was lath bainite and granular bainite when coiled at 300 ℃, and was granular bainite when coiled at 400 and 470 ℃. The yield strength and the tensile strength of the steel decrease first, and then increase with the increasing of coiling temperature, while the elongation appears opposite law. The changes of the mechanical properties were mainly depended on the phase transformation strengthening, precipitation hardening, as well as the size and shape of the M-A island. When the steel was coiled at 470 ℃, the yield strength and tensile strength reached 700 and 865 MPa respectively, and the elongation reached 18.9%.%与铌钒微合金化钢相比，钛微合金化钢有更低的成本，因此设计了一种低碳钛微合金化热轧高强钢，并利用扫描电镜（ SEM）和透射电镜（ TEM）等仪器研究了不同卷取温度对实验钢组织和性能的影响．结果表明：卷取温度对实验钢的组织与力学性能有较大的影响，300℃卷取时得到板条贝氏体和粒状贝氏体的混合组织，400和470℃卷取时得到粒状贝氏体组织；实验钢的屈服强度和抗拉强度均随卷取温度的升高呈现出先下降再上升的规律，延伸率呈现出先升高再下降的规律，分析认为力学性能的变化主要由相变强化、析出强化以及M-A岛的尺寸和形态共同决定；470℃卷取时实验钢有较好的综合力学性能，屈服强度和抗拉强度分别达到了700和865 MPa，延伸率达到了18．9％．
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