GB/T 7736-2008 in English

《GB/T 7736-2008钢的低倍缺陷超声波检验法》由TC183（全国钢标准化技术委员会）归口，TC183SC14（全国钢标准化技术委员会金相检验方法分会）执行，主管部门为中国钢铁工业协会。
本标准代替GB/T 7736-2001《钢的低倍组织及缺陷超声波检验法》。
本标准规定了钢的低倍缺陷超声波检验的术语和定义、方法原理、检验方法、对比试块的要求与制备、检验设备及其调试、检验条件和步骤、结果评定、检验报告等。
本标准适用于方型、矩型、圆型等简单截面的轧制、锻造钢材（坯）低倍缺陷的超声波检验，也适用于
其他钢制备件、坯料的缺陷检验。
本标准与GB/T 7736-2001相比，主要变化如下：
―――标准名称修改为《钢的低倍缺陷超声波检验法》；
―――本标准将原标准中的公式（1）、公式（2）、公式（3）、公式（4）、公式（5）加了限制条件即“Xs≥3N和Xf≥３N”；
―――将原标准中的“应使扫描区域的宽度大于产品的完整横截面，覆盖率大于２０％”修改为“扫查
间距不得超过探头有效声束宽度的50%~80%”；
―――增加“表4 短横孔判伤界限表”。

1 Scope
This standard specifies terms and definitions of Ultrasonic inspecting method for macro-structure and imperfection of steel, together with the method principle, inspection method, requirements and preparations for reference block, testing apparatus and its debugging, condition for surveys and procedure, result evaluation, inspection report and so on.
This standard is applicable to the rolling of simple sections of square type, moment type, circle type, Ultrasonic inspecting method for macro-structure and imperfection of forging steel (base), and Ultrasonic inspecting of other steel spare parts and blanks.

2 Normative Reference
The following normative documents contain provisions which, through reference in this standard, constitute provisions of this standard. For dated reference, subsequent corrections to, or revisions of, any of these publications do not apply. However, all parties coming to an agreement according to this standard are encouraged to study whether the latest edition of these documents is applicable. For undated normative references, the latest edition is applicable to this standard.