GB/T 43320-2023 in English

《GB/T 43320-2023焊缝无损检测 超声检测 薄壁钢构件自动相控阵技术的应用》由TC55（全国焊接标准化技术委员会）归口，TC55SC3（全国焊接标准化技术委员会焊缝试验和检验分会）执行，主管部门为中国机械工业联合会。

GB/T 43320-2023 Non-destructive testing of welds - Ultrasonic testing - Use of automated phased array technology for thin-walled steel components

1 Scope

This document specifies the application of phased array technology for the semi- or fully automated ultrasonic testing of fusion-welded joints in steel parts with thickness values between 3.2 mm and 8.0 mm. This meets the typical range of tube wall thickness values in boilers, which is an important application of this testing technology. The minimum and maximum value of the wall thickness range can be exceeded, when testing level “D” of this document is applied. This document applies to full penetration welded joints of simple geometry in plates, tubes, pipes, and vessels, where both the weld and parent material are low-alloy and/or fine grained steel.

Note: “Semi-automated testing” encompasses a controlled movement of one or more probes on the surface of a component along a fixture (guidance strip, ruler, etc.), whereby the probe position is unambiguously measured with a position sensor. The probe is moved manually. “Fully automated testing” includes mechanized propulsion in addition.

Where material-dependent ultrasonic parameters are specified in this document, they are based on steels having a sound velocity of (5920 ± 50) m/s for longitudinal waves, and (3255 ± 30) m/s for transverse waves. It is necessary to take this fact into account when testing materials with a different velocity.

This document provides guidance on the specific capabilities and limitations of phased array technology for the detection, location, sizing and characterization of discontinuities in fusion-welded joints. Ultrasonic phased array technology can be used as a stand-alone technique or in combination with other non-destructive testing (NDT) methods or techniques, during manufacturing and testing of new welds/repair welds (pre-service testing).

This document specifies two testing levels:

——level “C” for standard situations;

——level “D” for different situations/special applications.

This document describes assessment of discontinuities for acceptance purposes based on:

——height and length;

——amplitude (equivalent reflector size) and length;

——go/no-go decision.

This document does not include acceptance levels for discontinuities.

2 Normative references

The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 5577 Non-destructive testing - Ultrasonic testing - Vocabulary
Note: GB/T 12604.1-2020, Non-destructive testing - Terminology - Ultrasonic testing (ISO 5577:2017, MOD)
ISO 9712 Non-destructive testing - Qualification and certification of NDT personnel
Note: GB/T 9445-2023, Non-destructive testing - Qualification and certification of NDT personnel (ISO 9712:2012, IDT)
ISO 17640 Non-destructive testing of welds - Ultrasonic testing - Techniques, testing levels, and assessment
Note: GB/T 11345-2023, Non-destructive testing of welds - Ultrasonic testing - Techniques, testing levels and assessment (ISO 17640:2018, IDT)
ISO 18563-1 Non-destructive testing - Characterization and verification of ultrasonic phased array equipment - Part 1: Instruments
ISO 18563-2 Non-destructive testing - Characterization and verification of ultrasonic phased array equipment - Part 2: Probes
ISO 18563-3 Non-destructive testing - Characterization and verification of ultrasonic phased array equipment - Part 3: Combined systems
ISO 23243 Non-destructive testing – Ultrasonic testing with arrays – Vocabulary1)

3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 5577 and ISO 23243 and the following apply.

3.1
phased array image
one- or two-dimensional display, constructed from the collected information of phased array operation

[SOURCE: ISO 23243:2020, 3.3.2.8]

3.2
indication
phased array indication
pattern or disturbance in the phased array image (3.1) which may need further evaluation

3.3
phased array set-up
probe arrangement defined by probe characteristics (e.g. frequency, probe element size, beam angle, wave mode), probe position, and the number of probes, adaptation to the curvature of the test object

[SOURCE: ISO 23243:2020, 3.3.1.3]

3.4
scan increment
distance between successive data collection points in the direction of scanning (mechanically or electronically)

[SOURCE: ISO 23243:2020, 3.3.1.5]

3.5
skewed scan
scan performed with a skewed beam angle

Note: The skewed beam angle can be achieved electronically or by changing the probe orientation.

[SOURCE: ISO 23243:2020, 3.3.1.6]


4 Testing levels

Quality requirements for welded joints are mainly associated with the material, welding process and service conditions. To accommodate all of these requirements, this document specifies two testing levels “C” and “D”. A written procedure is mandatory for both testing levels C and D.

Testing level C applies to the standardized approach for thin-walled components (see Tables 1 and 2), e.g. testing from two sides or testing from one side of the weld with the cap removed.

Testing level D shall be agreed upon for special applications, e.g. tests on wall thickness below 3.2 mm, varying thicknesses (counter bore) and tests at object temperatures outside the range specified in 7.6. For testing level D, verification on test blocks is mandatory.

In general, the testing levels are related to quality levels (given in ISO 5817, for example). The appropriate testing level can be specified by standards for weld testing (e.g. ISO 17635), product standards or other specifications. When ISO 17635 is specified, the recommended testing levels are as given in Table 1.

Table 2 shows the minimum requirements for the individual test modes for testing levels C and D. The set-up shall be verified with reference and/or test blocks; as described in 7.2. In cases where scanning is performed from one scanning surface (e.g. the outer surface of a vessel), at least half and full skip shall be used. If scanning is performed from both scanning surfaces (e.g. top and bottom surfaces), testing at half skip could be sufficient, depending on weld and probe dimensions.

If the evaluation of the indications is based on amplitude only, the deviation of the beam axis from the normal to the weld bevel shall not exceed 6°. In case it is not possible to stay within this 6° value, because of the geometry of the test object (e.g. weld cap, narrow gap weld), the scan plan shall describe the corrective measures and explain how the areas outside the 6° requirement are covered with sufficient sensitivity.