GB/T 5616-1985 Guidelines for the application of conventional non-destructive testing
Some standard content:
National Standard of the People's Republic of China
Guidlines for application of conventional nondestructive testing methodsUDC 620.179.1
GB 5616-85
The purpose of this standard is to guide the correct use of nondestructive testing technology and put forward the rules to be followed when applying conventional nondestructive testing methods. 1 General
1.1 Nondestructive testing is a method of detecting various macroscopic internal or surface defects of materials, components or equipment (tested objects) and judging their location, size, shape and type by using the interaction between sound, light, heat, electricity, magnetism and radiation and matter without damaging the performance of the tested object.
1.2 Conventional nondestructive testing methods include five types: ultrasonic, (x, y) radiography, magnetic powder, penetration and electromagnetic (eddy current). 1.3 Principles of applying nondestructive testing technology
1.3.1 When using nondestructive testing technology to detect products, the applicable testing method standards must be clearly specified and implemented in accordance with these standards. 1.3.2 When accepting products based on nondestructive testing results, the corresponding testing quality standards or technical conditions must be met. If there are no corresponding product testing quality standards, 2.3 of this standard should be followed. 1.3.3 Nondestructive testing personnel engaged in product inspection, equipment maintenance and safety supervision must have a nondestructive testing personnel technical qualification certificate issued by the relevant national competent authorities.
1.3.4 The performance of instruments and equipment used for nondestructive testing should meet the requirements for instruments and equipment in the corresponding testing method standards. 1.3.5 Standard devices used for nondestructive testing, such as standard test blocks for ultrasonic testing, image quality meters for radiographic testing, sensitivity test pieces for magnetic particle testing, and standard test pieces for penetrant testing, should be inspected or supervised by the product quality supervision unit. 1.3.6 When using non-destructive testing methods such as radiography that are harmful to the human body, necessary protective measures and monitoring methods should be available, and the relevant labor protection regulations issued by the labor and health departments should be followed. 2 General principles for determining product non-destructive testing standards 2.1 If a product can be tested according to a general method standard, then the testing method standard for the product should not be formulated. If a special product testing method standard must be formulated, its content must include, in addition to the relevant provisions of the general method standard, the content that specifically needs to be specified for the product.
2.2 When formulating the non-destructive testing acceptance standard for a product, reasonable quality requirements should be considered, and both the reliability of the product within the specified service life and its economic efficiency should be guaranteed.
2.3 If there is no testing method standard and quality acceptance standard for a product, the supply and demand parties may agree to adopt any of the following methods to determine the testing method and quality acceptance standard for the product.
2.3.1 Adopt or formulate a special product testing method and quality acceptance standard. 2.3.2According to the different acceptance levels in the general flaw detection method standards, a certain level is used to accept the product. 2.3.3Use a certain flaw detection method standard and specify specific product acceptance quality requirements. 3. Capabilities and applicable scope of conventional nondestructive flaw detection methods Note: The capabilities and applicable scope of conventional nondestructive flaw detection methods refer to the capabilities of current general methods and equipment. 3.1 Overview
Each nondestructive flaw detection method has its advantages and limitations. The probability of detecting defects by various methods is neither 100% nor completely the same. For example, the ultrasonic flaw detection method and the radiographic flaw detection method will not produce completely consistent flaw detection results for the same object under test. 3.1.1 Among the conventional non-destructive testing methods, ultrasonic and radiographic methods are mainly used to detect internal defects of the inspected object, magnetic powder and electromagnetic (eddy current) methods are used to detect surface and near-surface defects of the inspected object, and penetration methods are only used to detect defects with openings on the surface of the inspected object. 3.1.2 The area defects inside the inspected object, such as cracks, white spots, delamination and lack of fusion in welds, are usually detected by ultrasonic testing, while volume defects such as pores, slag inclusions, shrinkage cavities, looseness, etc. should generally be detected by radiographic testing. 3.2 Ultrasonic testing
3.2.1 Applicable objects and capabilities
3.2.1.1 Forgings: Ultrasonic testing can detect defects such as cracks, white spots, delaminations, large pieces or dense slag inclusions in forgings that are basically perpendicular to the ultrasonic beam. The direct method is usually used to detect internal defects, and its maximum effective detection depth can reach about 1m. The oblique method and surface wave method are used for flaw detection, which can detect defects that are not parallel to the surface or surface defects. Ultrasonic testing can determine the position and relative size of defects, but it is generally difficult to determine the type of defects.
Note: The concepts of relative size determined by different methods are different, and their sizes cannot be compared. 3.2.1.2 Welds: including butt welds and fillet welds of fusion welding. Ultrasonic testing can detect defects such as cracks, incomplete penetration, incomplete fusion, slag inclusions and pores in welds. The oblique projection method is usually used, and the maximum effective detection depth is about 200mm at 2.5MHz. Ultrasonic testing can determine the position and relative size of defects, but it is difficult to determine the type of defects. 3.2.1.3 Profiles: including metal plates, pipes, bars and other profiles. Ultrasonic testing can detect defects such as cracks, folds, delamination, and flaky slag inclusions inside and on the surface of the material. Generally, liquid immersion method or local water flooding method is used for flaw detection. For materials such as pipes and bars, focused oblique projection method is usually required for flaw detection. The position and relative size of defects can be determined, but it is difficult to determine the type of defects. 3.2.1.4 Castings: Cast steel or ductile iron parts with simple shapes, smooth surfaces or processed and trimmed can be inspected by ultrasonic method. It can detect defects such as hot cracks, cold cracks, looseness, slag inclusions, shrinkage cavities, etc. It can determine the location and relative size of defects, but it is difficult to determine the type of defects.
3.2.2 Inapplicable objectsbzxZ.net
Coarse-grained materials: such as austenitic steel castings and welds. a.
b. Workpieces with complex shapes or rough surfaces. 3.3 Radiographic flaw detection
3.3.1 Applicable objects and capabilities
3.3.1.1 Welds: It can detect defects such as incomplete penetration, pores, slag inclusions, etc. in welds. For cracks and lack of fusion, since the gap width is extremely narrow and the direction of the radiation is not easy to be consistent with the direction of the cracks and lack of fusion, it is difficult to detect cracks and lack of fusion in welds by radiographic method. The penetration depth of radiographic flaw detection is mainly determined by the energy of the rays. The thickness of steel that can be penetrated by 400kV x-rays can reach about 85mm, the thickness that can be penetrated by Drill 60 rays can reach about 200mm, and the thickness that can be penetrated by 9MeV linear accelerators can reach about 400mm. Radiographic methods can generally determine the position and size of the plane projection of defects and the types of defects. 3.3.1.2 Castings: can detect shrinkage cavities, slag inclusions, pores, looseness, hot cracks and other defects in castings. Generally, the position and size of the plane projection of defects and the types of defects can be determined. 3.3.2 Inapplicable objects
a. Forgings
b. Profiles
3.4 Magnetic particle inspection
3.4.1 Applicable objects
Ferromagnetic materials and workpieces, including forgings, welds, profiles, castings, etc., can detect surface and near-surface cracks, folds, interlayers, inclusions, pores and other defects. Generally, the position, size and shape of the defect can be determined, but it is difficult to determine the depth of the defect. 3.4.2 Inapplicable objects
Non-ferromagnetic materials, such as austenitic steel, copper, aluminum, etc. 3.5 Penetrant flaw detection (including color flaw detection and fluorescent flaw detection) 3.5.1 Applicable objects
GB 5616-85
Metallic materials and dense non-metallic materials. Surface-opening cracks, folds, looseness, pinholes and other defects can be found. Generally, the position, size and shape of the defect can be determined, but it is difficult to determine the depth of the defect. 3.5.2 Inapplicable objects
Loose porous materials.
3.6 Electromagnetic (eddy current) flaw detection
3.6.1 Applicable objects
Conductive materials, such as ferromagnetic and non-ferromagnetic profiles and parts, graphite products, etc. Surface and near-surface defects such as cracks, folds, pits, inclusions, looseness, etc. can be found. Usually the position and relative size of the defect can be determined, but it is difficult to determine the type of defect. 3.6.2 Inapplicable objects
Non-conductive materials.
Additional remarks:
This standard was proposed by the Ministry of Machinery Industry of the People's Republic of China and is under the jurisdiction of the Shanghai Materials Research Institute of the Ministry of Machinery Industry. This standard was drafted by the Shanghai Materials Research Institute of the Ministry of Machinery Industry. The main drafters of this standard are Jiang Fucai and Chen Zhunian. 285
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