分析了三代核电技术EPR压水堆型机组主泵螺栓的结构特性和磁特性，并根据主泵螺栓在役运行过程中螺纹区易产生的横向缺陷，制定了分段磁化及线圈剩磁法的磁粉检测工艺。检测结果表明，制定的分段磁化线圈剩磁法工艺优于国外核电站的线圈连续法工艺。

Through analyzing structural property and magnetic property of the primary pump bolts in the third generation nuclear power plant EPR pressurized water reactor and based on the fact that the primary pump bolts are liable to produce transverse crack in service, it is proposed that the primary pump bolts of threaded area are inspected by using segmental magnetization and coil residual magnetic method. The results show that the above-mentioned method is superior to the continuous magnetizing method used in foreign nuclear power station.