Non-Destructive Control (NC) - monitoring the reliability of the basic working properties and parameters of an object or its individual elements / nodes that do not require removal of an object from work or its dismantling.
There is also the concept of destructive testing (for example, crash tests of cars).
Content
Basic methods
The main methods of non-destructive testing are [1] [2] :
- magnetic - based on the analysis of the interaction of the magnetic field with a controlled object. It is used to detect defects in ferromagnetic metals (nickel, iron, cobalt and a number of alloys based on them);
- electric - based on the registration of the parameters of the electric field, interacting with a controlled object or arising in a controlled object as a result of external influence;
- eddy current based on the analysis of the interaction of the electromagnetic field of the eddy current transducer with the electromagnetic field of eddy currents induced in a controlled object;
- radio wave - based on the registration of changes in the parameters of the electromagnetic waves of the radio band, interacting with a controlled object;
- Heat - based on registration of changes in heat or temperature fields of controlled objects caused by defects. The main parameter in the thermal method is the temperature distribution over the object's surface, since it carries information about the features of the heat transfer process, its internal structure, the presence of hidden internal defects and the mode of operation of the object;
- Optical - based on the registration of parameters of optical radiation interacting with a controlled object;
- radiation - based on the registration and analysis of penetrating ionizing radiation after interacting with a controlled object. The word “radiation” may be replaced by a word denoting a specific type of ionizing radiation, for example, X-ray, neutron, etc .;
- acoustic (ultrasonic) - based on the registration of parameters of elastic waves excited or arising in a controlled object. When using elastic waves in the ultrasonic range (above 20 kHz ), it is permissible to use the term “ultrasonic” instead of the term “acoustic”;
- penetrating substances - based on the penetration of substances into the cavity of the defects of a controlled object. The term “penetrating substances” can be changed to “capillary”, and when detecting through defects - to “leak detection”;
- vibroacoustic - based on recording the parameters of a vibroacoustic signal that occurs when a controlled object is operating.
- Visual (VIC) - identification of burrs, dents, rust, burn-through, sagging, and other visible defects.
Control classification
| Type of control | By the nature of the interaction of physical fields with a controlled object | By the primary informative parameter | According to the method of obtaining primary information |
|---|---|---|---|
| Magnetic | Magnetic | Coercivity, Magnetization, Residual Induction, Magnetic Permeability, Barkhausen Effect Tension | Induction, Ferrozondovy, Magnetographic, Ponderomotive, Magnetoresistor |
| Electric | Electric, Triboelectric, Thermoelectric, | Electropotential, Electro capacitance | Electrostatic powder, Electroparametric, Electrospark, Recombination radiation, Exoelectron emission, Noise, Contact potential difference |
| Eddy current | Past Radiation, Reflected Radiation | Amplitude, Phase, Frequency, Spectral, Multifrequency | Transformer, Parametric |
| Radio wave | Past Radiation, Reflected Radiation, Scattered Radiation, Resonant | Amplitude, Phase, Frequency, Time, Polarizing, Geometric | Detector (diode), Bolometric, Thermistor, Interference, Holographic, Liquid crystals, Thermal paper, Thermoluminophores, Photo-controlled semiconductor plates, Calorimetric |
| Thermal | Thermal contact, convective, self-radiation, | Thermometric, Thermometric | Pyrometric, Liquid crystals, Thermal paints, Thermal papers, Thermoluminous materials, Thermodependent parameters, Optical, Interference, Calorimetric |
| Optic | Past Radiation, Reflected Radiation, Scattered Radiation, Induced Radiation | Amplitude, Phase, Frequency, Time, Polarizing, Geometric, Spectral | Interference, Nephelometrichesky, Holographic, Refractometric, Reflexometric, Visual-Optical, |
| Radiation | Past Radiation, Stray Radiation, Activation Analysis, Characteristic Radiation, Field Emission | Energy flux density, spectral | Scintillation, Ionization, Secondary Electrons, Radiographic, Radioscopic |
| Acoustic | Past Radiation, Reflected Radiation (Echo Method), Resonant, Impedance, Free Oscillations, Acoustic Emission | Amplitude, Phase, Time, Frequency, Spectral | Piezoelectric, Electromagnetic-acoustic, Microphone, Powder |
| Penetrating substances | Molecular | Liquid, Gas | Brightness (achromatic), Color (chromatic), Luminescent, Luminescent-color, Filterable particles, Mass spectrometry, Bubble, Gauge, Halogen |
| Vibroacoustic | Mechanical oscillations - the movement of a point or a mechanical system, during which oscillations occur, which characterize scalars | Statistical parameters of the oscillatory process (mechanical vibrations) | Piezoelectric. Electromagnetic Acoustic |
Nondestructive testing ( English Nondestructive testing (NDT) ) is also called a nondestructive evaluation (NDE) reliability test or nondestructive inspection (NDI ). NC is especially important when creating and operating vital products, components and structures. To identify various flaws, such as corrosive, rusting, cracking.
In international practice, the accepted abbreviations for the types of non-destructive testing (AWS) are given in the table:
| No. p / p | Type of control | Symbol |
|---|---|---|
| one | Acoustic emission control | Aet |
| 2 | Electromagnetic control | ET |
| 3 | Leak control | LT |
| four | Magnetic particle control | MT |
| five | Neutron flaw detection | NRT |
| 6 | Penetrant control | PT |
| 7 | Radiographic control | RT |
| eight | Ultrasound control | UT |
| 9 | Visual control | VT |
| ten | Vibroacoustic | VA |
These conventions are indicated in the drawings.
NK in industry
The purpose of using non-destructive testing in industry is to reliably identify dangerous defects. Therefore, the choice of specific methods of ND is determined by the detection efficiency of such a marriage. In practice, the most widely used ultrasound control , as having high sensitivity, mobility and environmental friendliness, as well as radiation, successfully detecting dangerous defects and objectively fixing the results [3] .
Depending on the tasks, use other methods of control. For example, to search for surface defects - capillary, and to identify end-to-end - leak detection.
Electric, magnetoelectric, magnetic and vortex methods allow to control the properties of conducting media, as a rule, on the surface and in the subsurface layer. More fully non-destructive testing is carried out by a combination of several methods [3] .
NK International Associations
- EFNDT (European Federation for Non Destructive Testing - European Federation of Non-Destructive Testing)
- ICNDT (The International Committee for Non-Destructive Testing - International Committee for Non-Destructive Testing)
- RSNTTD (Russian Society for Non-Destructive Testing and Technical Diagnostics - RSNTTD)
International exhibitions and conferences on NC
- Defectoscopy / NDT Exhibition [4]
- Forum "Territory NDT"
- Exhibition NDT Russia [5]
- All-Russian Conference on Non-Destructive Testing and Technical Diagnostics
- World Conference on Non-Destructive Testing (World NK Conference)
- European Conference on NDT (ECNDT) (European Conference on ND)
Magazines
- "Flaw Detection" (Russian Journal of Nondestructive Testing)
- "In the world of non-destructive testing"
- "Control. Diagnostics"
- “Technical Diagnostics and Non-Destructive Testing” (published by the E. O. Paton Electric Welding Institute )
- "NDT Territory"
Notes
- ↑ GOST 18353-79. Nondestructive control. Classification of species and methods
- ↑ GOST R 56542-2015. Nondestructive control. Classification of species and methods
- ↑ 1 2 V.N. Volchenko , A.K. Gurvich, A.N. Mayorov, L.A. Kashuba, E.L. Makarov, M.H. Khusanov Welding quality monitoring / Ed. V. N. Volchenko. - A manual for engineering universities. - M .: Mashinostroenie, 1975. - 328 p. - 40 000 copies
- ↑ “Defectoscopy” exhibition // Ndtworld.com website Neopr (Inaccessible link) . The appeal date is May 13, 2015. Archived May 7, 2015.
- ↑ International Exhibition of Equipment for Non-Destructive Testing and Technical Diagnostics NDT Russia . www.ndt-russia.ru. The appeal date is September 6, 2016.
See also
- Vibration diagnostics
- Flaw detector
- Flaw Detection (magazine)
- Introscopy
- Defects of welded joints