GB/T 5777-2008 in English

《GB/T 5777-2008无缝钢管超声波探伤检验方法》由TC183（全国钢标准化技术委员会）归口，TC183SC19（全国钢标准化技术委员会钢产品无损检测分会）执行，主管部门为中国钢铁工业协会。
本标准修改采用ISO 9303：1989（E）《承压无缝和焊接（埋弧焊除外）钢管纵向缺陷的全周向超声波检测》。
本标准规定了无缝钢管超声波探伤的探伤原理、探伤方法、对比试样、探伤设备、探伤条件、探伤步骤、结果评定和探伤报告。
本标准适用于各种用途无缝钢管纵向、横向缺陷的超声波检验。本标准所述探伤方法主要用于检验破坏了钢管金属连续性的缺陷，但不能有效地检验层状缺陷。
本标准适用于外径不小于6mm且壁厚与外径之比不大于0.2的钢管。壁厚与外径之比大于0.2的钢管的检验，经供需双方协商可按本标准附录C执行。
电磁超声探伤可参照此标准执行。
本标准代替GB/T 5777-1996《无缝钢管超声波探伤检验方法》，与GB/T 5777-1996相比主要变化如下：
――范围增加“电磁超声探伤可参照此标准执行”（见第1章）；
――增加了对斜向缺陷的检验及检验方法；
――修改了管端人工槽位置的限制；
――修改了人工缺陷的尺寸和代号；
――探头工作频率由2.5MHz~10MHz修改为1MHz~15MHz。

Scope

This standard specifies the ultrasonic flaw detection principle, flaw detection method, comparison sample, flaw detection equipment, flaw detection conditions, flaw detection steps, result evaluation and flaw detection report of seamless steel tubes. This standard is applicable to ultrasonic inspection of longitudinal and transverse defects of seamless steel tubes for various purposes. The flaw detection method described in this standard is mainly used to detect defects that destroy the metal continuity of steel tubes, but cannot effectively detect laminar defects. This standard is applicable to steel tubes with an outer diameter of not less than 6mm and a ratio of wall thickness to outer diameter of not more than 0.2. For the inspection of steel tubes with a ratio of wall thickness to outer diameter greater than 0.2, it is necessary to negotiate between the supply and demand parties and can be carried out in accordance with Appendix C of this standard. Electromagnetic ultrasonic flaw detection can be carried out in accordance with this standard.