GB/T 29712-2023 Active

This document describes the two acceptance levels (AL 2 and AL 3) for ultrasonic testing of ferritic fully penetrated welded joints according to the B and C grade weld quality requirements specified in ISO 5817:2014. Welds meeting the D grade weld quality requirements described in ISO 5817:2014 are generally not subject to ultrasonic testing, and therefore the corresponding ultrasonic testing acceptance levels for D grade welds are not included in this document. The acceptance levels specified in this document apply to ultrasonic testing performed in accordance with ISO 17640. This document is applicable to ultrasonic testing of ferritic fully penetrated welds with thicknesses ranging from 8 mm to 100 mm. If the detection sensitivity specified in the acceptance levels of this document can be achieved while taking into account the geometry and acoustic properties of the workpiece, this document is also applicable to welds of other types, materials, and thicknesses. Unless material attenuation or higher probe resolution requirements dictate the use of probes operating at other frequencies, the nominal probe frequency used in this document is 2 MHz to 5 MHz. When using probes operating outside this frequency range for detection, careful consideration should be given to the relevance of the acceptance levels.