AS 2574-2000

Sets out requirements for ultrasonic testing equipment and methods for the testing of specified areas of heat-treated ferritic steel castings (15mm or greater in thickness), using A-scan presentation. The casting wall is divided into three zones and acceptance criteria are specified for three stress levels. Appendices provide guidance on the use of the Standard, guidance on the nature and identification of discontinuities and procedures for the sizing of discontinuities.

This Standard sets out methods for the ultrasonic testing of specified areas of heat-treated ferritic steel castings that are 15 mm or greater in thickness, using A-scan presentation. It employs three evaluation sensitivity levels and divides the casting wall thickness into zones.NOTES: 1 Advice and recommendations on information to be supplied by the purchaser at the time of enquiry and order are contained in the purchasing guidelines set out in Appendix A.2 This Standard does not apply to the testing of austenitic steel castings, unless by agreement, because such castings have a columnar structure which is not amenable to grain refining by heat treatment.3 The level of evaluation of discontinuities is normally specified in relevant product Standards or is determined by agreement between the contracting parties after due consideration of the size, configuration and the service requirements of the casting.4 Steel deposited during repair welding is deemed to be part of the casting.5 This Standard does not include methods for the ultrasonic immersion testing of castings.Procedures described in this Standard enable the test operator to determine the location, size, shape and often, the identification of discontinuities in all specified zones of heat-treated steel castings. To enable the accurate sizing of discontinuities, castings should be machined or ground to provide optimum probe contact. For unmachined castings it is necessary that some form of surface preparation be carried out.The recording requirements and the acceptance criteria, as specified in Sections 3 and 5 respectively, may not apply to complicated castings where heavy indentations or shapes are to be produced by machining, e.g. gear teeth or splines, because the zone parameters (see Section 5) cannot be rigidly applied.NOTE: In such cases the recording/acceptance criteria is subject to negotiation between the purchaser and the supplier.Although the methods outlined in this Standard are intended to be applied to heat-treated castings, they may be used on non heat-treated castings, by agreement, provided that it is recognized that some types of discontinuity may be difficult to detect in structures that have not been grain refined. In this case, an acceptance standard cannot be applied. For non heat-treated castings, where direct comparison with standard fine grained calibration blocks, or the use of recognized distance-gain-size (DGS) principles, is not appropriate, alternative blocks, or sections of the casting itself, should be used to evaluate discontinuities.

Originated as AS 2574-1982.
Second edition 2000.