International Organization for Standardization

Non-destructive testing - Ultrasonic testing - Reference blocks and test procedures for the characterization of contact probe sound beams - Second Edition
 N 12715

Annotation

This International Standard introduces two metal reference blocks, the hemicylindrical-stepped (HS) block and the side-drilled-hole (SDH) block. This International Standard establishes procedures for measuring the sound beam profiles generated by probes in contact with the test object. The probes include straight-beam, angle-beam (refracted compressional and refracted shear wave), focused beam, and dual-element probes. The side dimension of the probe has to be no greater than 25 mm.

The methodology of this International Standard provides guidelines for probes to be used for different metals including forged or rolled steel, aluminium, or titanium alloy products. The frequency range of the probes used in this International Standard extends from 1 MHz to 15 MHz, where 1 MHz to 5 MHz is best suited for steels and 5 MHz to 15 MHz is best for fine grain structured alloys such as aluminium products.

If this International Standard is to be used for materials other than steels, users should be aware of the fact that the wave velocities in these materials can be different from that of steels and the angle-beam probes are normally designed based on the steel applications. Snell's law of refraction is described in this International Standard so that correct angles of refraction in other homogeneous and fine-grained materials can be calculated. This International Standard applies to angle-beam probes of all practical angles (0° to 70°) and to focused and dual-element probes. This International Standard does not address the use of surface (Rayleigh) wave probes.

This International Standard does not address the estimation of equivalent defect sizes which requires reference blocks with flat-bottomed holes. This International Standard establishes no acceptance criteria, but does establish the technical basis for criteria that can be defined by users.