中文摘要：

根据磁偶极子理论，建立稳恒微弱垂直弱磁场作用下高压管类试件线状缺陷产生的漏磁场模型。根据磁偶极子空间磁场分布，导出了在外部垂直方向弱磁场下管状工件表面细长缺陷产生的弱磁场法向分量的计算公式。分析了不同纵向磁化强度下，作为磁记忆检测方法重要判据的磁场法向零值线形状及分布特点。

英文摘要：

According to the theory of magnetic dipole, the leakage field model of a high-pressure-tube with linear defect was established in vertical low-intensity field. Based on the spatial distribution of magnetic dipole, the equation of the normal component of leakage magnetic field on the tube surface under low-intensity field was derived. Under different longitudinal magnetization, the shape and characteristic of the zero value line of the normal component for the magnetic leakage field which was an important criterion for magnetic memory testing was analyzed.