This test method covers the procedures for the standard practice of performing ultrasonic shear and longitudinal wave examinations on turbine-generator steel retaining rings. A pulsed reflection-type ultrasonic instrument shall be used for the tests. Scanning of steel specimens may be performed by either the contact (stationary) or immersion (rotating) methods, both of which may be executed in either the axial or circumferential directions. Tests shall be performed after specimens have gone through final processing and heat treatment for properties, and the circumferential and axial faces machined flat and parallel to one another. Also prior to testing, surface examinations shall be made for surface roughness and tears, loose scales, machining or grinding particles, paint, and other foreign and extraneous matter. Suitable couplant liquids, capable of conducting ultrasonic vibrations, shall be used to couple the transducer to test surfaces.

1.1 This practice covers the procedures to be followed when performing ultrasonic shear and longitudinal wave tests on turbine-generator retaining rings with an inside diameter to wall thickness ratio equal to or greater than 5:1 and with wall thicknesses from 1 to 4 in. (25 to 102 mm).

1.2 Although this practice describes methods of ultrasonically testing retaining rings by either the contact or immersion method, it shall not restrict the use of improved inspection methods as they are developed. It is recognized that techniques for examination and evaluation may be chosen in order to enhance or improve the results or to accommodate variations in procedures, equipment, or capabilities. Considering these characteristics, forgings may be inspected by a combination of both the contact and the immersion methods, as mutually agreed upon between the manufacturer and the purchaser.

1.3 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.

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 and health practices and determine the applicability of regulatory limitations prior to use.