1 Scope
This standard specifies the magnetic particle examination method and magnetic particle indication defect evaluation of steel forgings.
This standard is applicable to the testing of cracks and other defects on or near the surfaces of steel forgings.
2 Normative References
The following standards contain provisions which, through reference in this text, constitute provisions of this standard. At the time of publication, all editions indicated are valid. All standards are subject to revision, and Parties concerned are encouraged to discuss the possibility of applying the latest edition of the following standards.
GB 9445-88 Qualification and certification for nondestructive testing personnel
GB/T 12604.5-90 Non-destructive testing - Terminology - Terms used in magnetic particle testing
3 Definitions
The following definitions are adopted according to GB/T 12604.5:
3.1 Magnetic particle indication
It refers to the magnetic particle accumulation formed by magnetic leakage due to the defects or other factors.
3.2 Magnetic particle examination method
It refers to the non-destructive testing method to discover the discontinuity on or near the surfaces of test specimens with the magnetic leakage and appropriate examination media.
3.3 Noncorrelation indication
It refers to the indication not caused by the discontinuity.
3.4 Threadiness magnetic particle indication
It refers to the magnetic particle indication whose length is not less than three times of the width and not less than 1.6mm.
Note: this definition is from Article 3.1.2 of ASTM A275/A275M-90.
4 Application Criteria
4.1 The supply and demand parties enter into an agreement on the following items of the forgings need magnetic particle examination according to the requirements of the contract or technical conditions:
a) Positions need magnetic particle examination on the forgings;
b) Types, size, quantity, positions and directions of magnetic particle indication regarded as the defects;
c) Current types, magnetic particle applying methods, demagnetization requirements and magnetic field intensity, etc.
4.2 Acceptance standard.
