1 Scope
This standard specifies the time of flight diffraction technique and the imperfection assessment requirements for welded joints of steel structures and equipment in hydroelectric or hydraulic engineering.
This standard is applicable to the time of flight diffraction technique of butt welded joints of non-alloy steel, low alloy steel and alloy steel used for the engineering structures with base metal thickness of 12mm~400mm. Other types of metal materials may refer to this standard.
2 Normative References
The following documents are indispensable for the application of this document. For dated references, only the dated edition is applicable to this document. For undated references, the latest edition (including all the amendments) applies.
GB/T 19799.1 Non-destructive Testing—Ultrasonic Testing—Calibration Block No.1
JB/T 10061 Commonly Used Specification for A-mode Ultrasonic Flaw Detector Using Pulse Echo Technique
3 Terms and Definitions
Foreword II
1 Scope
2 Normative References
3 Terms and Definitions
4 General Requirements
5 Detection System
6 Test Blocks
7 Inspection Level
8 Detection Equipment
9 Setting and Calibration of Detection System
10 Detection
11 Detection Data Analysis
12 Auxiliary Detection on Related Display Discovered by Non-parallel Scan
13 Imperfection Assessment
14 Detection Record and Report
Appendix A (Informative) Commonly Used Non-alloy Steel, Low Alloy Steel and Alloy Steel in Hydroelectric or Hydraulic Engineering
Appendix B (Informative) Reference Blocks
Appendix C (Informative) Calculation of Imperfection Depth and Height and Surface Dead Zone Height
Appendix D (Informative) TOFD Images of Common Welding Imperfections
Appendix E (Informative) TOFD Report of Welds
