中文摘要：

通过实验室热轧试验，研究了不同终轧温度下低硅含磷系热轧TRIP钢的组织特征及性能特点。结果表明：终轧温度由900℃降低到790℃，铁素体体积分数增加，贝氏体体积分数降低，残余奥氏体体积分数变化不太明显；终轧温度900和820℃时，得到贝氏体为基体的室温组织；终轧温度降低到790℃时，低温变形促进了奥氏体到铁素体的相变率，基体组织尺寸为约4．5μm的细小均匀的等轴状铁索体晶粒，而且存在大量位错。与其他工艺相比，终轧温度790℃时具有优良的综合力学性能：抗拉强度825MPa，断后总伸长率21．5％，屈强比0．64。

英文摘要：

The microstructure and mechanical properties of different finishing temperatures for hot rolled low silicon containing phosphorus TRIP steel were investigated using a laboratory hot rolling mill. The results show that when finishing temperature is decreased from 900 to 790 ℃, the volume fraction of ferrite is increased; the volume fraction of bainite is decreased; and the volume fraction of retained austenite has no evident changes. When finishing temperature are 900 and 820 ℃, hainite is used as matrix microstructure. Lower temperature deformation enhances the transformation rate of austenite to ferrite, also the fine, uniform and equiaxed ferrite grains can be obtained as matrix microstructure, the average ferrite grain size is about 4.5μ m, and the dislocations is observed in matrix, when finishing temperature is decreased to 790 ℃. Compared with other kind of processes, the steels have excellent mechanical properties when finishing temperature is 790 ℃： ultimate tensile strength, elongation and yield/strength ratio are 825 MPa, 21.5% and 0.64 respectively.