Standard Practice for Use of the Ultrasonic Time of Flight Diffraction (TOFD) Technique

Importancia y uso:

4.1 This practice provides general principles for the application of the Time-of-Flight Diffraction technique as a tool for detection and sizing of discontinuities.

4.2 TOFD is a nondestructive ultrasonic examination technique that is not based on amplitude response. However, sufficient sensitivity is required to identify indications for evaluation.

4.3 TOFD techniques are typically applied to welded joints in carbon steel, but the principles may be applicable to other applications including other materials with suitable validation procedures agreeable to the contracting parties.

4.4 In addition to a stand-alone ultrasonic detection technique, TOFD may be used in conjunction with weld examinations such as those described in Practices E164 and E1961 where it may be used to improve sizing estimates of flaws detected by the manual or mechanized pulse-echo techniques and help discriminate between flaws and geometric reflectors.

4.5 The technique has proven effective on thicknesses from 9 mm to 300 mm [0.375 in. to 12 in.]. TOFD has been used on thicknesses outside of this range but special considerations are necessary. Techniques developed outside of this range of thickness shall be demonstrated as capable of meeting the required detection and sizing requirements of the specification used.

Subcomité:

E07.06

Referida por:

E3166-20E01

Volúmen:

03.03

Número ICS:

25.160.40 (Welding joints and welds)

Palabras clave:

flaw-height sizing; flaw sizing; nondestructive testing; time-of-flight-diffraction; TOFD; ultrasonic;