This national standard specifies the general methods for testing the defects in the weld joints/heat-affected zone, determining the defect position/size and evaluating the defects, as well as classifying the testing results.
This national standard is applicable to manual ultrasonic testing under complete-penetration butt-weld impulse reflection method for the ferrite steel whose thickness of base metal is no less than 8 mm.
This national standard is not applicable to the welds of the cast steel and Austenitic stainless steel, the butt welds of the steel tube whose external diameter is less than 159 mm, the fillet welds of tube base whose internal diameter is less than or equal to 200 mm, and the longitudinal welds of the tube whose external diameter is less than 250mm and internal-external diameter ratio is less than 80%.
1. Subject content and application scope
2. Normative References
3. Terms and Definitions
3.1 Simplified Horizontal Distance, l’
3.2 Defect’s indicated length, △l
3.3 Breadth of the probe interface, W
3.4 Longitudinal defect
3.5 Transverse defect
3.6 Geometric critical angle, β
3.7 Parallel Scan
3.8 Oblique parallel scan
3.9 Defect detection section
3.10 Benchmark line of tandem
3.11 Reference line
3.12 Tandem scan of transverse squareness
3.13 Tandem scan of vertical squareness
4. Test personnel
5. Defect detector, probe and system performance
5. 1 Defect detector
5.2 Probe
5.3 System performance
5.4 Defect detector, probe and system performance and periodic inspection
6. Test block
7. Inspection classification
7.1 Inspection classification
7.2 Inspection scope of the inspection grades
8. Inspection preparation
8.1 Defect detection surface
8.2 Testing frequency
8.3 Probe angle
8.4 Couplant
8.5 Testing of base metal
9. Adjustment and inspection of the instrument
9.1 Adjustment of the baseline scan
9.2 Drawing of the distance amplitude curve (DAC)
9.3 Verifying of the adjustment of instrument
10. Initial testing
10.1 General requirements
10.2 Testing of the slab butt weld
10.3 Testing of the butt weld of curved surface work-pieces
10.4 Testing for joints of other structures
11 Specified testings
11.1 General requirements
11.2 Determination of the maximal reflected wave amplitude
11.3 Determination of location parameter
11.4 Determination of the size parameter
12 Evaluation of defect
13 Grade classification of inspection result
14 Record and report
Annex A Supplementary) Shape and size of standard test block
Annex B (Supplementary) Shape and size of standard test blocks
Annex C (Supplementary) Tandem scan detection method
Annex D (Supplementary) Plotting of Distance-Amplitude Curve (DAC)
Annex E (Supplementary) Determination of the acoustic energy transmission loss error
