全自动超声波检测技术（AUT）以其高效、精确、环保等优势，成为海底管道环焊缝的首选检测方法，AUT检测技术的相关标准要求应用于海底管道环焊缝检测的AUT工艺必须进行工艺评定，而工艺评定中最重要的环节就是宏观切片试验。加工了6条管径为508 mm，壁厚分别为31.6 mm和28.4 mm的人工缺陷焊缝（共58个人工缺陷）。描述了人工缺陷的宏观切片方法与步骤，包括缺陷标记、绘制参考线、宏观切片、表面处理、切片标记、金相照相、数据分析等。最后，通过对比分析AUT检测数据和宏观切片数据，评定了AUT检测工艺的缺陷高度定量精度。

Automated ultrasonic testing (AUT) method is often the first choice on inspection of the girth welds of the subsea pipeline because of its advantage of efficiency, accuracy and environment-friendly behavior. According to the AUT standard, the AUT system should meet the requirement of system qualification test before its application to the inspection of the girth weld of the subsea pipeline, for which the macro sectioning plays a key role in the AUT system qualification. In the macro sectioning, 6 test coupons (58 defects in total) with the dimension of OD of 508 mm, WT of 31. 6 mm & 28. 4 mm, respectively, have been manufactured. The method of macro sectioning includes: defect identification, scribing the lines, macro section, surface preparation, marking and photographing. Eventually, with the comparison between AUT data evaluation and macro section, the defect height sizing accuracy of AUT system can be qualified.