中文摘要：

在带钢连续退火实验机上，对一种含Cu低碳实验钢进行了Q＆P处理，并使用扫描电镜、电子背散射衍射、X射线衍射、透射电镜及室温拉伸实验等手段对其显微组织和力学性能进行了表征．结果表明，富Cu粒子可以在Q＆P处理过程中析出，呈圆球形，直径多为9-20nm，弥散分布于马氏体板条内部．根据Orowan机制，该析出相对强度的贡献量约为134MPa．同时观察到，钢中残余奥氏体的形貌分布各异，主要有薄膜状、小颗粒状和大块状．实验钢的综合力学性能良好，强塑积可达21．2GPa·％，抗拉强度达到1326MPa，延伸率16．0％，其优异的综合力学性能主要得益于残余奥氏体的形变诱发相变，即TRIP效应．

英文摘要：

A low carbon steel containing Cu addition was treated by Q＆P process using a CAS 200 continuous annealing simulator. The microstructure of the steel was characterized by means of SEM, EBSD, XRD and TEM and its mechanical properties were investigated by tensile testing at room temperature. Cu-rich precipitates formed during the Q＆P process were observed as spherical particles in martensitic laths and are 9 nm to 20 nm in diameter. According to the Orowan mechanism, those fine particles may have a contribution to the yield strength of the steel about 134 MPa. Also observed are three different morphologies of the retained austenite phase in the test steel, i.e. thin film-like, fine granular and blocky, formed at different locations. The test steel has a good comprehensive mechanical properties, of which the product of tensile strength and elongation, the tensile strength and the total elongation are as high as 21.2 GPa.%, 1326 MPa and 16.0%, respectively. The excellent combined properties can be attributed to the effect of transformation induced plasticity （TRIP） caused by the retained austenite.