NB/T 20003.5-2021 Non-destructive testing for mechanical components in nuclear island of nuclear power plants - Part 5: Magnetic particle testing
1 Scope
This document specifies the technical requirements for continuous magnetic particle testing of mechanical components in nuclear island of nuclear power plants.
This document is applicable to magnetic particle testing during the manufacturing and installation of ferromagnetic materials, parts and components, and welded joints in mechanical components in nuclear island of nuclear power plants. It is not applicable to the testing of non-ferromagnetic materials.
2 Normative references
The following documents contain requirements which, through reference in this text, constitute provisions 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.
GB/T 4956 Non-magnetic coatings on magnetic substrates - Measurement of coating thickness - Magnetic method
GB 11533 Standard for logarithmic visual acuity charts
GB/T 12604.5 Non-destructive testing - Terminology - Terms used in magnetic particle testing
GB/T 15822.2 Non-destructive testing-Magnetic particle testing - Part 2: Detection media
GB/T 15822.3 Non-destructive Testing - Magnetic Particle Testing - Part 3: Equipment
GB/T 23906 Non-destructive testing - Rings for magnetic particle testing
GB/T 23907 Non-destructive testing - Shims for magnetic particle testing
JB/T 6870 Specifications for the mobile rotating-field flaw detectors
JB/T 7411 Non-destructive testing instruments - Specification of electricity magnetic yoke magnetic particle flaw detector
JB/T 8290 Non-destructive testing instruments - Magnetic particle flaw detectors
NB/T 20003.1-2021 Non-destructive testing for mechanical components in nuclear island of nuclear power plants - Part 1: General requirements
3 Terms and definitions
For the purpose of this document, the terms and definitions given in GB/T 12604.5 and NB/T 20003.1-2021 apply.
3.1
magnetization by electric current flow
establishing a magnetic field by passing electric current (AC, rectified, or DC) through the entire workpiece or a part of it
3.2
magnetization by magnetic flow
establishing a magnetic field in the entire workpiece or a part of it by electromagnetic yoke or indirect induction
3.3
relevant indication
magnetic particle indication formed by the flux leakage field caused by defects attracting magnetic particles during magnetic particle testing, generally referred to as defect indication
3.4
non-relevant indication
magnetic particle indication formed by the flux leakage field caused by changes in cross-section or material permeability attracting magnetic particles during magnetic particle testing
3.5
false indication
magnetic particle indication not formed by the flux leakage field attracting magnetic particles
4 General requirements
4.1 Testing personnel
The testing personnel shall meet the requirements of NB/T 20003.1.
The testing personnel shall undergo vision examination annually. Their uncorrected or corrected near vision shall not be less than 4.8, and the test method shall meet the requirements of GB 11533.
The testing personnel shall undergo color vision examination annually, and such examination shall not reveal color blindness or color weakness.
4.2 Testing documents
The testing procedures, process cards or other testing documents shall meet the requirements of NB/T 20003.1-2021, 5.4. Magnetic particle testing shall be conducted according to effective testing procedures.
The testing procedures shall cover at least the following contents:
——Scope of application: type, size, testing range and material of the tested workpiece;
Foreword i 1 Scope 2 Normative references 3 Terms and definitions 4 General requirements 5 Magnetic particle testing equipment and apparatus 6 Calibration and verification 7 Magnetizing electric currents 8 Testing methods 9 Testing process 10 Testing report Annex A (Normative) System performance verification of fixed magnetic particle flaw detectors Annex B (Normative) Standard test rings, and reference test pieces for performance test of detection media Annex C (Informative) Relationship among peak, average and effective values of several sine wave currents Annex D (Informative) Typical magnetization methods of welded joints
