针对700MPa级热轧高强带钢同卷力学性能出现波动的问题，采用扫描电镜、透射电镜观察，EBSD分析以及物理化学相分析等手段，同时通过拉伸试验及温度测定等措施对波动现象进行了研究。结果表明，钢卷沿轧制方向力学性能分布不均，头部、尾部的强度偏差较大，中间强度相对稳定。头部、中间、尾部沉淀强化，位错强化以及细晶强化效果的不同，决定了钢卷不同部位的强化差别较大，为实际生产高强钢提供了理论依据。

In accordance with the problem of strength fluctuation with the same high strength hot strip roll, by means of SEM, TEM, EBSD and chemical phase analysis, the phenomenon of strength fluctuation has been studied through these experiments of tensile test and temperature detection. The results show that mechanical properties of hot rolled high strength steel are uneven. The head and tail of steel are very different, while the middle part is even. This phenonmen is decided by difference of precipitation strengthening, dislocation strengthening and fine crystal grain strengthening in the different parts of the same coil. So it can supply the help to manufacture high strength steel with the field produce.