【国外标准】 Standard Specification for Straight-Beam Ultrasonic Examination of Rolled Steel Plates for Special Applications

This procedure covers the standard and acceptance standards for straight-beam, pulse-echo, ultrasonic examination of rolled carbon and alloy steel plates. The amplitude linearity of the apparatus to be used shall be checked by positioning the transducer over the depth resolution notch in the IIW or similar block. The inspection shall be performed in an area free of operations that interfere with proper performance of the test. The test shall be performed either by direct contact, immersion, or liquid column coupling. Grid scanning shall be conducted along a continuous perpendicular line on the center. All discontinuities causing complete loss of reflection shall be recorded.1.1 This specification2 covers the procedure and acceptance standards for straight-beam, pulse-echo, ultrasonic examination of rolled carbon and alloy steel plates, 3/8 in. [10 mm] in thickness and over, for special applications. The method will detect internal discontinuities parallel to the rolled surfaces. Three levels of acceptance standards are provided. Supplementary requirements are provided for alternative procedures.1.2 Individuals performing examinations in accordance with this specification shall be qualified and certified in accordance with the requirements of the latest edition of ASNT SNT-TC-1A or an equivalent accepted standard. An equivalent standard is one which covers the qualification and certification of ultrasonic nondestructive examination candidates and which is acceptable to the purchaser.1.3 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.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.