GB/T 9444-2019 Steel and iron castings – Magnetic particle inspection
1 Scope
This standard specifies the general requirements, acceptance criteria, classification and evaluation of indication, re-inspection, inspection records and reports of magnetic particle inspection for steel and iron castings.
This standard is applicable to magnetic particle inspection of defects on the surface and near surface of ferro-magnetic steel and iron castings.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB/T 5097 Non-destructive testing - Penetrant testing and magnetic particle testing - Viewing conditions (GB/T 5097-2005, ISO 3059:2001, IDT)
GB/T 9445 Non-destructive testing - Qualification and certification of NDT personnel (GB/T 9445-2015, ISO 9712: 2012, IDT)
GB/T 12604.5 Non-destructive testing Terminology Magnetic particle testing
GB/T 15822.1 Non-destructive testing - Magnetic particle testing - Part 1: General principles (GB/T 15822.1-2005, ISO 9934-1: 2001, IDT)
GB/T 15822.2 Non-destructive testing - Magnetic particle testing - Part 2: Detection media (GB/T 15822.2-2005, ISO 9934-2: 2002, IDT)
GB/T 15822.3 Non-destructive testing - Magnetic particle testing - Part 3: Equipment(GB/T 15822.3-2005, ISO 9934-3: 2002, IDT)
GB/T 23906 Non-destructive testing - Rings for magnetic particle testing
GB/T 23907 Non-destructive testing - Shims for magnetic particle testing
3 Terms and definitions
For the purposes of this standard, the terms and definitions given in GB/T 12604.5 and the following apply.
3.1
non-linear indications
SM
indications when the length (L) is smaller than 3 times the width (b), i.e., L < 3b
3.2
linear indications
LM
indications when the length (L) is greater than or equal to 3 times the width (b), i.e., L ≥ 3b
3.3
aligned indications
AM
indications when 3 or more non-linear indications are on the same line and spaced less than 2 mm
indications where 2 linear indications are on the same line and spaced less than the longest indication length
4 General requirements
4.1 General principle
4.1.1 If not stipulated in this standard, the technical requirements, methods, media, equipment, etc. of magnetic particle inspection shall be implemented in accordance with GB/T 15822.1, GB/T 15822.2 and GB/T 15822.3.
4.1.2 Workplaces shall be well ventilated and away from heat and fire sources, and inspection materials and equipment shall be used in accordance with the manufacturer's instructions.
4.1.3 Standard test piece in GB/T 23907 is used to verify the comprehensive performance of magnetic particle inspection, and the test piece is divided into three types by sensitivity: high, medium and low. The central conductor method shall be verified using the annular test block of GB/T 23906.
4.1.4 Comprehensive performance test shall be carried out before the inspection starts. Generally, standard test pieces or annular test block are used. When there is no provision by users or technical documents, A1-30/100 test pieces are recommended. A more efficient method can also be used to inspect representative workpieces with known defect types, locations, sizes, and distributions. The workpieces shall have been demagnetized and have no residual indication from previous inspections.
4.2 Ordering instructions
When conducting magnetic particle inspection, the manufacturer and the purchaser shall specify the following content:
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 General requirements
5 Acceptance criteria
6 Classification and evaluation of indications
7 Re-inspection
8 Inspection records and reports
Annex A (Informative) Comparison between international standard and original standard in terms of clause/subclause numbers and their reasons
Annex B (Informative) Recommended surface roughness for magnetic particle inspection
Annex C (Informative) Reference figures for quality level in non-linear indications (SM) (isolated)
Annex D (Informative) Reference figures for quality level in linear indication (LM) and aligned indications (AM)
Annex E (Informative) Format of magnetic particle inspection report
Bibliography
