本文件规定了厚度为6 mm至300 mm的铁素体钢全熔透焊缝飞行时间衍射技术（TOFD）的验收等级，符合ISO 5817的质量等级。这些验收等级适用于根据ISO 10863分类的指示。

This document specifies acceptance levels for the time‑of‑flight diffraction technique (TOFD) of full penetration welds in ferritic steels from 6 mm up to 300 mm thickness which correspond to the quality levels of ISO 5817. These acceptance levels are applicable to indications classified in accordance with ISO 10863.