Non-destructive testing (END; in English, NDT, from nondestructive testing) is called any type of test carried out on a material that does not permanently alter its physical, chemical, mechanical or dimensional properties). Non-destructive testing is opposed to destructive testing in that it involves imperceptible or no damage. The different methods are based on the application of physical phenomena such as electromagnetic, acoustic, elastic waves, emission "Emission (physics)") of subatomic particles, capillarity, absorption "Absorption (chemistry)") and any type of test that does not involve considerable damage to the sample examined.
The terms non-destructive inspection, non-destructive testing, non-destructive examination and non-destructive evaluation are commonly used synonymously.
In general, nondestructive testing provides less accurate data about the state of the variable to be measured than destructive testing. However, they are usually cheaper for the owner of the piece to be examined, since they do not involve its destruction. Sometimes, non-destructive tests only seek to verify the homogeneity and continuity of the analyzed material, which is why they are complemented with data from destructive tests.
The wide application of non-destructive testing methods on materials is summarized in the following three groups:
• - Defectology. It allows the detection of discontinuities, evaluation of corrosion and deterioration due to environmental agents, determination of stresses, detection of leaks.
• - Characterization. Evaluation of the chemical, structural, mechanical and technological characteristics of the materials; physical properties (elastic, electrical and electromagnetic); heat transfers and isotherm tracing.
Nondestructive testing has been practiced for many decades. There has been a record since 1868 when work with magnetic fields began. One of the most used methods was the detection of superficial cracks in railway wheels and axles. The pieces were immersed in oil, and then cleaned and sprinkled with a powder. When a crack was present, the oil that had leaked into the discontinuity wetted the dust that had spread, indicating that the component was damaged. This led to the formulation of new oils that would be used specifically to perform these and other inspections, and this inspection technique is now called penetrant testing (PT).
Surface integrity test
Introduction
Non-destructive testing (END; in English, NDT, from nondestructive testing) is called any type of test carried out on a material that does not permanently alter its physical, chemical, mechanical or dimensional properties). Non-destructive testing is opposed to destructive testing in that it involves imperceptible or no damage. The different methods are based on the application of physical phenomena such as electromagnetic, acoustic, elastic waves, emission "Emission (physics)") of subatomic particles, capillarity, absorption "Absorption (chemistry)") and any type of test that does not involve considerable damage to the sample examined.
The terms non-destructive inspection, non-destructive testing, non-destructive examination and non-destructive evaluation are commonly used synonymously.
In general, nondestructive testing provides less accurate data about the state of the variable to be measured than destructive testing. However, they are usually cheaper for the owner of the piece to be examined, since they do not involve its destruction. Sometimes, non-destructive tests only seek to verify the homogeneity and continuity of the analyzed material, which is why they are complemented with data from destructive tests.
The wide application of non-destructive testing methods on materials is summarized in the following three groups:
• - Defectology. It allows the detection of discontinuities, evaluation of corrosion and deterioration due to environmental agents, determination of stresses, detection of leaks.
• - Characterization. Evaluation of the chemical, structural, mechanical and technological characteristics of the materials; physical properties (elastic, electrical and electromagnetic); heat transfers and isotherm tracing.
However, with the development of production processes, the detection of discontinuities was no longer sufficient. It was also necessary to have quantitative information on the size of the discontinuity, to use it as a source of information, in order to perform mathematical calculations and thus be able to predict the mechanical life of a component. These needs led to the emergence of Non-Destructive Evaluation (NDE) as a new discipline. As a result of this technological revolution, a series of events would arise in the field of PND that would establish its current condition.
In 1941, the American Society for Non-Destructive Testing (ASNT) was founded, which is the largest technical society in the world for non-destructive testing. This society promotes the exchange of technical information on PND, as well as educational materials and programs. It is also the creator of standards and services for the qualification and certification of personnel who perform non-destructive testing, under the American scheme.
Below are a series of dates related to historical events, discoveries, advances and applications of some non-destructive tests.
• - 1868: First attempt to work with magnetic fields.
• - 1879: David Hughes establishes a testing field.
• - 1879: David Hughes studies Foucault currents.
• - 1895: Wilhelm Röntgen studies the cathode ray tube.
• - 1895: Wilhelm Röntgen discovers X-rays.
• - 1896: Henri Becquerel discovers gamma rays.
• - 1900: Beginning of penetrating liquids in FFCC.
• - 1911: ASTM establishes the MT Technique Committee.
• - 1928: Industrial use of magnetic fields.
• - 1930: Theodore Zuschlag") obtains a patent based on eddy currents.
• - 1931: First installed industrial system based on eddy currents.
• - 1941: Fluorescent liquids appear.
• - 1945: Dr. Floyd Firestone") works with ultrasound.
• - 1947: Dr. Elmer Sperry applies ultrasound testing in industry.
The entity that brings together all duly constituted institutions is the International Committee for Non-Destructive Testing (ICNDT) based in Vienna.
Globalization in world markets has marked the development of non-destructive testing, which already has a reach in every corner of the planet, and currently there are non-destructive testing societies in most countries, such as the Argentine Society of Non-Destructive Testing (AAENDE), the Australian Institute for Non-Destructive Testing (AINDT), the Austrian Society of Non-Destructive Testing (OGFZP), the Belgian Association of Non-Destructive Testing (BANT), The Brazilian Society for Non-Destructive Testing (ABENDE), The Canadian Society for Non-Destructive Testing (CSNDT), The Chinese Society for Non-Destructive Testing (ChSNDT), The Mexican Institute of Non-Destructive Testing A.C. (IMENDE A.C.), Mexican Association of Non-Destructive Testing (AMEXEND A.C.).
Applications
Non-destructive testing is used in a variety of branches covering a wide range of industrial activities.
• - In the automotive industry:
Engine parts
Chassis.
• - In aviation and aerospace industry:
Exterior
Chassis
*Generating plants")
Jet engines "Reactor (engine)")
Space rockets.
• - Under construction:
Integrity tests on piles and screens
Structures
Bridges.
• - In manufacturing:
Machine parts.
• - In nuclear engineering:
Containers under pressure.
• - In petrochemicals:
Pipeline transportation
Storage tanks.
• - Miscellaneous
Amusement park attractions
Conservation-restoration of works of art.
Methods and techniques
Contenido
La clasificación de las pruebas no destructivas se basa en la posición en donde se localizan las discontinuidades que pueden ser detectadas, por lo que se clasifican en:.
Superficial non-destructive testing
These tests provide information about the surface health of the inspected materials. Superficial PND methods are:.
• - VT – Visual inspection.
• - PT – Penetrating liquids.
• - MT – Magnetic particles").
• - ET – Electromagnetism.
In the case of using VT and PT, there is the limitation of detecting only superficial discontinuities (open to the surface); and with MT and ET you have the possibility of detecting both superficial and sub-surface discontinuities (those found below the surface but very close to it).
Volumetric non-destructive testing
These tests provide information about the internal health of the inspected materials. The volumetric PND methods are:.
• - RT – Industrial radiography").
• - UT – Industrial ultrasound").
• - AE – Acoustic emission").
These methods allow the detection of internal and subsurface discontinuities, as well as under certain conditions, the detection of surface discontinuities.
Non-destructive leak testing
These tests provide information on the degree to which fluids can be contained in containers, without escaping into the atmosphere or becoming out of control. The PND methods of airtightness are:.
• - Leak tests").
• - Pressure change tests") (pneumatic or hydrostatic).
• - Bubble tests").
• - Tests by mass spectrometer").
• - Leak tests with halogen tracers.
Common non-destructive testing
• - ACFM (Alternative Current Field Measurement) "ACFM (Alternative Current Field Measurement)".
• - Oil analysis.
• - Vibration analysis.
• - Noise analysis").
• - Induced currents").
• - Ferrography.
• - Inspection by penetrating liquids.
• - Inspection by magnetic particles.
• - Weld inspection").
• - Ultrasound inspection.
• - Loss of magnetic flux").
• - X-ray.
• - Thermography.
• - Ultrasound.
• - Integrity tests on piles and screens.
• - Mechanical impedance in deep foundations.
• - Sonic transparency in deep foundations.
• - Materials engineering.
• - Materials testing.
• - Destructive test").
• - Mexican Institute of Non-Destructive Testing A.C.
• - Spanish Association of Non-Destructive Testing.
• - AAENDE - Argentine Association of Non-Destructive Testing.
• - Uruguayan Association of Non-Destructive Testing.
• - The American Society for Nondestructive Testing (in English).
Nondestructive testing has been practiced for many decades. There has been a record since 1868 when work with magnetic fields began. One of the most used methods was the detection of superficial cracks in railway wheels and axles. The pieces were immersed in oil, and then cleaned and sprinkled with a powder. When a crack was present, the oil that had leaked into the discontinuity wetted the dust that had spread, indicating that the component was damaged. This led to the formulation of new oils that would be used specifically to perform these and other inspections, and this inspection technique is now called penetrant testing (PT).
However, with the development of production processes, the detection of discontinuities was no longer sufficient. It was also necessary to have quantitative information on the size of the discontinuity, to use it as a source of information, in order to perform mathematical calculations and thus be able to predict the mechanical life of a component. These needs led to the emergence of Non-Destructive Evaluation (NDE) as a new discipline. As a result of this technological revolution, a series of events would arise in the field of PND that would establish its current condition.
In 1941, the American Society for Non-Destructive Testing (ASNT) was founded, which is the largest technical society in the world for non-destructive testing. This society promotes the exchange of technical information on PND, as well as educational materials and programs. It is also the creator of standards and services for the qualification and certification of personnel who perform non-destructive testing, under the American scheme.
Below are a series of dates related to historical events, discoveries, advances and applications of some non-destructive tests.
• - 1868: First attempt to work with magnetic fields.
• - 1879: David Hughes establishes a testing field.
• - 1879: David Hughes studies Foucault currents.
• - 1895: Wilhelm Röntgen studies the cathode ray tube.
• - 1895: Wilhelm Röntgen discovers X-rays.
• - 1896: Henri Becquerel discovers gamma rays.
• - 1900: Beginning of penetrating liquids in FFCC.
• - 1911: ASTM establishes the MT Technique Committee.
• - 1928: Industrial use of magnetic fields.
• - 1930: Theodore Zuschlag") obtains a patent based on eddy currents.
• - 1931: First installed industrial system based on eddy currents.
• - 1941: Fluorescent liquids appear.
• - 1945: Dr. Floyd Firestone") works with ultrasound.
• - 1947: Dr. Elmer Sperry applies ultrasound testing in industry.
The entity that brings together all duly constituted institutions is the International Committee for Non-Destructive Testing (ICNDT) based in Vienna.
Globalization in world markets has marked the development of non-destructive testing, which already has a reach in every corner of the planet, and currently there are non-destructive testing societies in most countries, such as the Argentine Society of Non-Destructive Testing (AAENDE), the Australian Institute for Non-Destructive Testing (AINDT), the Austrian Society of Non-Destructive Testing (OGFZP), the Belgian Association of Non-Destructive Testing (BANT), The Brazilian Society for Non-Destructive Testing (ABENDE), The Canadian Society for Non-Destructive Testing (CSNDT), The Chinese Society for Non-Destructive Testing (ChSNDT), The Mexican Institute of Non-Destructive Testing A.C. (IMENDE A.C.), Mexican Association of Non-Destructive Testing (AMEXEND A.C.).
Applications
Non-destructive testing is used in a variety of branches covering a wide range of industrial activities.
• - In the automotive industry:
Engine parts
Chassis.
• - In aviation and aerospace industry:
Exterior
Chassis
*Generating plants")
Jet engines "Reactor (engine)")
Space rockets.
• - Under construction:
Integrity tests on piles and screens
Structures
Bridges.
• - In manufacturing:
Machine parts.
• - In nuclear engineering:
Containers under pressure.
• - In petrochemicals:
Pipeline transportation
Storage tanks.
• - Miscellaneous
Amusement park attractions
Conservation-restoration of works of art.
Methods and techniques
Contenido
La clasificación de las pruebas no destructivas se basa en la posición en donde se localizan las discontinuidades que pueden ser detectadas, por lo que se clasifican en:.
Superficial non-destructive testing
These tests provide information about the surface health of the inspected materials. Superficial PND methods are:.
• - VT – Visual inspection.
• - PT – Penetrating liquids.
• - MT – Magnetic particles").
• - ET – Electromagnetism.
In the case of using VT and PT, there is the limitation of detecting only superficial discontinuities (open to the surface); and with MT and ET you have the possibility of detecting both superficial and sub-surface discontinuities (those found below the surface but very close to it).
Volumetric non-destructive testing
These tests provide information about the internal health of the inspected materials. The volumetric PND methods are:.
• - RT – Industrial radiography").
• - UT – Industrial ultrasound").
• - AE – Acoustic emission").
These methods allow the detection of internal and subsurface discontinuities, as well as under certain conditions, the detection of surface discontinuities.
Non-destructive leak testing
These tests provide information on the degree to which fluids can be contained in containers, without escaping into the atmosphere or becoming out of control. The PND methods of airtightness are:.
• - Leak tests").
• - Pressure change tests") (pneumatic or hydrostatic).
• - Bubble tests").
• - Tests by mass spectrometer").
• - Leak tests with halogen tracers.
Common non-destructive testing
• - ACFM (Alternative Current Field Measurement) "ACFM (Alternative Current Field Measurement)".
• - Oil analysis.
• - Vibration analysis.
• - Noise analysis").
• - Induced currents").
• - Ferrography.
• - Inspection by penetrating liquids.
• - Inspection by magnetic particles.
• - Weld inspection").
• - Ultrasound inspection.
• - Loss of magnetic flux").
• - X-ray.
• - Thermography.
• - Ultrasound.
• - Integrity tests on piles and screens.
• - Mechanical impedance in deep foundations.
• - Sonic transparency in deep foundations.
• - Materials engineering.
• - Materials testing.
• - Destructive test").
• - Mexican Institute of Non-Destructive Testing A.C.
• - Spanish Association of Non-Destructive Testing.
• - AAENDE - Argentine Association of Non-Destructive Testing.
• - Uruguayan Association of Non-Destructive Testing.
• - The American Society for Nondestructive Testing (in English).