ASTM A388/A388-19 pdf free download.Standard Practice for Ultrasonic Examination of Steel Forgings.
1 .1 This practice 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 he regarded separately as standard. The values stated in each system may not he 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 specification 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 he furnished to inch-pound units.
4. 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 he clearly stated as order requirements.
5. Ordering Information
5. 1 When this practice is to be applied to an inquiry, contract, or order, the purchaser shall so state and shall also furnish the following information:
5.1.1 Designation number (including year date),
5.1.2 Method of establishing the sensitivity in accordance with 9.2.2 and 9.3.3 (DGS (Distance Gain Size). Vec- or rectangular-notch).
5.1.2.1 The diameter and test metal distance of the flat- bottom hole and the material of the reference block in accordance with 9.2.2.2,
5.1.3 Quality level for the entire forging or portions thereof in accordance with 12.3, and
5.1.4 Any options in accordance with 1.5, 6.4, 6.5, 7.1, 8.1,
8.2, 9.1.11, 10.1, 10.2. and 12.2.
6. Apparatus
6.1 Elect ronic Apparatus—An ultrasonic. pulsed. reflection type of instrument shall be used for this examination. The system shall have a minimum capability for examining at frequencies from 1 to 5 MHz. On examining austenitic stainless forgings the system shall have the capabilities for examining at frequencies down to 0.4 MHz.
6. 1. 1 Apparatus Qualification (111(1 Calibration—Basic qualification of the ultrasonic test instrument shall be performed at intervals not to exceed 12 months or whenever maintenance is pertormed that affects the equipment function. The date of the last calibration and the date of the next required calibration shall be displayed on the test equipment.
6.1.2 The ultrasonic instrument shall provide linear presentation (within 5 %) for at least 75 % of the screen height (sweep line to top of screen). The 5 % linearity referred to is descriptive of the screen presentation of amplitude. Instrument linearity shall be verified in accordance with the intent of Practice E3 17. Any set of blocks processed in accordance with Practice E3l7 or E428 may be used to establish the specified ±5 % instrument linearity.ASTM A388/A388 pdf download.