This part of GB/T 7233 specifies the terms, definitions and general requirements for the ultrasonic examination of steel castings (with ferritic structure) for highly stressed components, and the methods for determining internal discontinuities by the pulse echo technique.
This part applies to the ultrasonic examination of steel castings which have usually received a grain-refining heat treatment and which have wall thicknesses up to and including 600 mm. For greater wall thicknesses, special agreements apply with respect to the examination techniques and recording limits.
This Part does not apply to austenitic steel.
Foreword i
1. Scope
2. Normative References
3. Terms and Definitions
4. General Requirements
4.1 Order Information
4.2 Extent of Examination
4.3 Maximum Permissible Size of Discontinuities
4.4 Personnel Qualification
4.5 Wall-section Zones
4.6 Severity Levels
5. Examination
5.1 General
5.2 Material
5.3 Equipment, Coupling Medium, Sensitivity and Resolution of Detection
5.4 Preparation of Steel Casting Surfaces for Testing
5.5 Examination Procedure
5.6 Test Report
Appendix A (Normative) Resolution of Detection of the Instrument/Probe Combination
Appendix B (Informative) Sound-beam Diameters
Appendix C (Informative) Types of Discontinuities
Appendix D (Informative) Transfer Correction
Appendix E (Informative) Determination of Coupling Transfer Correction
