ISO 22825-2012 pdf free download.Non-destructive testing of welds – UIltrasonic testing – Testing of welds in austenitic steels and nickel-based alloys.
In addition to a general knowledge of ultrasonic weld testing, the operators shall be familiar with and have practical experience in testing problems specifically associated with the type of materials and weld joints to be tested. Specific training and examination of personnel should be performed on representative pieces (duplex, austenitic, stainless steel) containing welds and using dual-element longitudinal wave probes. This training and the examination results should be documented.
If this is not the case, specific training and examination should be performed with the finalized ultrasonic testing procedures and selected ultrasonic testing equipment on representative samples containing natural or artificial reflectors similar to those expected. This training and the examination results should be documented.
6 Equipment
The equipment used for testing shall fulfil the requirements of EN 12668-1 and EN 12668-2. The verification of the combined equipment shall be done in accordance with EN 12668-3, with the exception of dual-element compression wave angle beam probes, which can be verified on appropriate reference blocks other than the blocks mentioned in EN 12668-3,
Focal curves shall be available for the dual-element probes to be used, determined on a material representative of the material to be tested.
7 Range setting for compression waves
Range setting shall be carried out on appropriate calibration blocks, e.g. on blocks which are designed to be similar to block No. 2 (see ISO 7963) as shown in Annex B. The dimension of at least one of the radii of the block used shall be close to the focal distance of the probes.
The index point of each probe shall be marked on the probe’s side, after having optimized the echo amplitude on the radius closest to its focal distance. Since echo optimization can be difficult for high-angle probes and creeping wave probes, the shear wave component may be used for optimization instead. In that case, the calibration methodology shall be included in the test procedure.
Optimization of the echoes shall be done on the two radii separately, and by iteration until the signals from the smaller and the larger radius are on their correct positions.
Alternatively, the time base may be set with the aid of a single-element straight beam probe on the width of the calibration block, and subsequent zero point adjustment with the angle probe placed on the calibration block, on the radius which is closest to the probe’s focal distance.
Range setting shall be carried out prior to each testing. Checks to confirm these settings shall be performed at least every 4 h and on completion of testing.
Checks shall also be carried out whenever a system parameter is changed or whenever changes in the equivalent settings are suspected.
If deviations are found during these checks, corrective actions shall be carried out as specified in Table 1.ISO 22825 pdf download.