1 Subject content and application scope
This standard specifies the general methods for detecting location and size of welding flaws and evaluating welding flaws, as well as methods for grading quality of welds. These methods use ultrasonic flaw testing with single or double crystal angle beam probe to contact objects for detecting fusion welds between structural steel members and cone heads or sealing plates on bolted spherical joints, as well as detecting butt welds of steel pipes.
This standard is applicable to manual A-scan pulse-echo ultrasonic flaw testing of welds between steel members (common-carbon and low-alloy, with base metal thickness of 3.5 mm~25 mm and pipe diameter of not less than 48 mm) and cone heads or sealing plates, as well as butt welds of steel pipes (with base metal thickness of 3.5 mm~25 mm and pipe diameter of not less than 48 mm), and also applicable to quality grading according to the testing result.
2 Normative references
GB 50205 Code for acceptance of construction quality of steel structures
GB 11345 Method for manual ultrasonic testing and classification of testing results for ferritic steel welds
JGJ 7 Technical specification for design and construction of space grid structures
ZBY 231 Testing methods for performance of probes used in ultrasonic flaw detection
ZBY 232 Technical conditions for No.1 standard test block for ultrasonic crack detection
ZB J04 001 Practice for evaluating performance characteristics of A scope ultrasonic pulse-echo testing system
GB 11533 Standard for logarithmic visual acuity charts
3 Testing personnel
3.1 Testing personnel to perform ultrasonic testing for welding flaws of space grid structures must master the basic knowledge and skills of ultrasonic testing, have experience in surface welding flaws testing, have been trained and assessed in accordance with the relevant national provisions, and hold corresponding qualification and level certificates for non-destructive testing personnel issued by relevant assessment organizations.
3.2 On-site ultrasonic testing for welding flaws must comply with relevant safety regulations. When the testing conditions do not meet the requirements for testing process or the operation conditions are not safe, the testing personnel shall be entitled to stop the testing until the conditions are improved to meet the requirements before testing again.
3.3 The vision of testing personnel shall be checked once a year in accordance with those specified in GB 11533, and the corrected vision shall not be lower than 5.0.
1 Subject content and application scope
2 Normative references
3 Testing personnel
4 Flaw detector, probe and coupling agent
5 Test blocks
6 Preparation before testing
7 Testing methods
8 Flaw evaluation
9 Classification and grading requirements
10 Testing after weld repair
11 Record and report
Annex A (Informative) Shape and size of CSK-IC of steel grid structure
Annex B (Informative) Shape and size of RBJ-1 reference block
Annex C (Informative) Measurement of sensitivity margin of flaw detector
Annex D (Informative) Performance test methods of double-crystal angle beam probe
Annex E (Informative) Ultrasonic flaw detection report and record of steel space grid structures with bolted joints
