ASTM A388/A388M-23 pdf free standard 钢锻件超声波检验标准实施规程

ASTM A388/A388M-23 pdf free standard,Standard Practice for Ultrasonic Examination of Steel Forgings
钢锻件超声波检验的标准实施规程

Abstract

This practiceASTM A388/A388M-23  covers the examination procedures for the contact, pulse-echo ultrasonic examination of heavy steel forgings by the straight and angle-beam techniques. An ultrasonic, pulsed, reflection type of instrument shall be used and shall provide linear presentation for at least 75% of the screen height. The 5% linearity referred to is descriptive of the screen presentation of amplitude. The electronic apparatus shall contain an attenuator, search units, transducers, couplants, reference blocks, and DGS scales. The forging shall be machined to provide cylindrical surfaces for radial examination in the case of round forgings. The ends of the forgings shall be machined perpendicular to the axis of the forging for the axial examination. Faces of disk and rectangular forgings shall be machined flat and parallel to one another. The procedures to be performed are as follows: ultrasonic examination of the forgings; straight-beam examination with establishment of the instrument sensitivity and calibration either by the reflection, reference-block technique, or DGS method; and angle-beam examination used for rings and hollow forgings.

Scope

1.1 This practice2 covers the examination procedures for the contact, pulse-echo ultrasonic examination of steel forgings by the straight and angle-beam techniques. The straight beam techniques include utilization of the DGS (Distance Gain-Size) method. See Appendix X3.

1.2 This practice is to be used whenever the inquiry, contract, order, or specification states that forgings are to be subject to ultrasonic examination in accordance with Practice A388/A388M.

1.3 Supplementary requirements of an optional nature are provided for use at the option of the purchaser. The supplementary requirements shall apply only when specified individually by the purchaser in the purchase order or contract.

1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.

1.5 This practice and the applicable material specifications are expressed in both inch-pound units and SI units. However, unless the order specifies the applicable “M” specification designation [SI units], the material shall be furnished to inch-pound units.

Significance and Use

4.1 This practice shall be used when ultrasonic inspection is required by the order or specification for inspection purposes where the acceptance of the forging is based on limitations of the number, amplitude, or location of discontinuities, or a combination thereof, which give rise to ultrasonic indications.

4.2 The ultrasonic quality level shall be clearly stated as order requirements.

摘要

本实施规程涵盖了采用直射和角度波技术对重型钢锻件进行接触式、脉冲-回波超声波检验的检验程序。应使用超声波、脉冲、反射型仪器，并在至少75%的屏幕高度提供线性显示。所述的5%线性是指幅度的屏幕显示。电子设备应包含衰减器、探头、换能器、耦合剂、参考块和DGS比例尺。对于圆形锻件，应对其进行加工，以提供用于径向检查的圆柱形表面。对于轴向检查，锻件的末端应垂直于锻件轴加工。圆盘和矩形锻件的表面应加工成平坦且彼此平行的表面。应执行的程序如下：锻件的超声波检查；通过反射、参考块技术或DGS方法建立仪器灵敏度和校准的直射波检查；以及用于环和空心锻件的角度波检查。

范围

1.1 本实施规程涵盖了采用直射和角度波技术对钢锻件进行接触式、脉冲-回波超声波检验的检验程序。直射波技术包括DGS（距离增益-尺寸）方法的应用。请参见附录X3。

1.2 只要询价、合同、订单或规范规定了按照A388/A388M实施规程对锻件进行超声波检验，就应使用本实施规程。

1.3 提供了选择性的补充要求，可由采购方选择使用。这些补充要求仅在采购订单或合同中单独指定时适用。

1.4 以国际单位制（SI）或英制单位表示的数值应分别视为标准。每种制度中所述的数值可能并非完全相等；因此，应独立使用每种制度。将两种制度的值合并可能导致不符合标准。

1.5 本实施规程和适用的材料规范均以英制单位和国际单位制表示。但是，除非订单指定适用的“M”规范编号（国际单位制），否则材料应提供英制单位。

意义与用途

4.1 当订单或检验规范要求超声波检验以确定锻件的接受情况时，应采用本实施规程。其接受与否基于超声波指示所产生的不连续性的数量、幅度或位置的限制，或二者的组合。

4.2 超声波质量等级应明确规定为订单要求。