冷轧压下率对1180 MPa级复相钢组织性能的影响

利用Gleeble-3500热模拟机模拟1180 MPa级复相钢连续退火过程,利用扫描电镜和拉伸试验机研究冷轧压下率对复相钢组织演变规律及力学性能的影响。结果表明,在相同热处理条件下,随着冷轧压下率的增加,复相钢中马氏体、贝氏体所占比例逐渐减小,铁素体回复再结晶程度逐渐增加,复相结构逐渐减弱;冷轧压下率越大,后续热处理过程中的碳原子扩散能力越强,力学性能逐渐下降;当冷轧压下率为30%时,试验钢组织内部的铁素体、马氏体、贝氏体三相复合结构最完整,此时试验钢具有最优的强度与塑性。

Effect of cold rolling reduction ratio on microstructure and properties of 1180 MPa grade complex phase steel

Continuous annealing process of a 1180 MPa grade complex phase steel was simulated by Gleeble-3500 thermal simulator, and the effect of cold rolling reduction ratio on microstructure evolution and mechanical properties of the complex phase steel was studied by means of scanning electron microscope and tensile testing machine. The results show that under the same heat treatment conditions, as the cold rolling reduction ratio increases, the proportion of martensite and bainite in the complex phase steel gradually decreases, the degree of ferrite recovery and recrystallization gradually increases, and the complex microstructure gradually weakens. The larger the cold rolling reduction ratio is, the stronger the carbon atom diffusion ability is in the subsequent heat treatment process, and the mechanical properties gradually deteriorate. With the cold rolling reduction ratio of 30%, the ferrite+martensite+bainite complex phase microstructure in the steel is the most complete, and the steel has the optimal strength and plasticity.