以X42钢膨胀波纹管为研究对象，利用光学金相和扫描电镜，研究了冷轧后、退火后的显微组织及变化规律。结果表明：热处理前后膨胀波纹管的中部、凸缘部和边部的横纵截面组织相差不大，热处理后不同部位组织相差也不大，但热处理前后焊缝方向靠近外弧带状组织消除状况与其他部位消除状况的不均匀性，分析认为是引起波纹管弯曲变形的因素之一。研究结果为进一步找出膨胀管弯曲变形的原因并形成膨胀波纹管形状稳定性控制方案提供了基础。

The microstructures of X42 expandable convoluted tube was studied by optical microscopy and scanning electron spectroscopy after cold rolling and annealing, respectively. It was found that the microstructures of cross- and longitudinal- sections have not obvious differences, and those in different parts even have not obvious differences, while banded structure of outer part of weld seam was eliminated the most evidently, considering as one factor inducing the bent of expandable convoluted tube. The results provide basis for further revealing the mechanism of the bent and controlling the shape stability.