1 Prepared by – patel sahil – patel savan patel shani Sub: MSM ( ) Topic Name : NDT-(Non - Destructive Testing) 10 June June June 2016 Guided by – Prof. MANISH K. PRAJAPATI

The use of noninvasive techniques to determine the integrity of a material, component or structure or quantitatively measure some characteristic of an object. Definition of NDT (NDE) Hashmukh Goswami College of Engineering, Vahelal2 College code - 024

 liquid penetration testing(LPT)  Magnetic particles testing(MPT)  Radiography  Ultrasonic testing(UT)  eddy-current testing(ECT) Most common methods of NDT: 3 College code Hashmukh Goswami College of Engineering, Vahelal

Definition: An NDT method that is used to reveal surface breaking flaws through bleedout of a colored or fluorescent dye from the flaw  It is also known as dye penetrant testing.  One of the oldest and most widely used NDT method.  Can be used on metals and nonmetal including glass, rubber, plastics and ceramics. Liquid Penetration Test 4 College code Hashmukh Goswami College of Engineering, Vahelal

Application of LPT : This method is capable of detecting discontinuities open to the surface of the material under test.This method is capable of detecting discontinuities open to the surface of the material under test. These are cracks, laps, seams, porosity, etc. Detected easily.These are cracks, laps, seams, porosity, etc. Detected easily. This method is much reliable for detecting fatigue cracks which occur during the service life of a material.This method is much reliable for detecting fatigue cracks which occur during the service life of a material. 5 College code Hashmukh Goswami College of Engineering, Vahelal

 Cleaning : the surface to be cleaned by tested is cleaned to remove any dirt, dust particles, oil film, paint.the surface to be cleaned by tested is cleaned to remove any dirt, dust particles, oil film, paint. if these are not removed they do not to entire into the defects and may create wrong indications.if these are not removed they do not to entire into the defects and may create wrong indications. Cleaning can be done by solvents, alkaline, vapour degreasing.Cleaning can be done by solvents, alkaline, vapour degreasing. Fig. cleaning and drying of test surface 6 College code Hashmukh Goswami College of Engineering, Vahelal

Application of penetrant: This usually includes dye by spraying, compete immersion of specimen in dye container.This usually includes dye by spraying, compete immersion of specimen in dye container. During this step the fluid should spread freely & evenly over the surface and move into the crack/cavity.During this step the fluid should spread freely & evenly over the surface and move into the crack/cavity. It depends on the environment of testing area such as temperature & surface inclination.It depends on the environment of testing area such as temperature & surface inclination. This time is called as ‘dwell time’. Usually smaller flaws will take more dwell time.This time is called as ‘dwell time’. Usually smaller flaws will take more dwell time. Fig. Application Of penetrant 7 College code Hashmukh Goswami College of Engineering, Vahelal

 Inspection : With the help of visible light or radiation can be used to observe the indication provided by the test by an inspectorWith the help of visible light or radiation can be used to observe the indication provided by the test by an inspector Indication : The color of the dye oozed out on the surface of the specimen can be seen as an indication of the presence of some defect open to the surface.The color of the dye oozed out on the surface of the specimen can be seen as an indication of the presence of some defect open to the surface. 8 College code Hashmukh Goswami College of Engineering, Vahelal

Removal of excess penetrant : The excess penetrant removal is required for the reason that this excess penetrant will hide the actual indications.The excess penetrant removal is required for the reason that this excess penetrant will hide the actual indications. It must be removed from the specimen surface.It must be removed from the specimen surface. The method of removing is depended on the penetrant used.The method of removing is depended on the penetrant used. Common removers are simple water wash, using oil or chlorine based solvent.Common removers are simple water wash, using oil or chlorine based solvent. The cleaning method is mainly depend on the size, shape, material of the components.The cleaning method is mainly depend on the size, shape, material of the components. Fig. Removal of excess penetrant 9 College code Hashmukh Goswami College of Engineering, Vahelal

Application of developer : Usually a white color developer is applied on the surface for a better contrast with red color of dye.Usually a white color developer is applied on the surface for a better contrast with red color of dye. Developer including dry powder, water soluble, water suspendible are in use.Developer including dry powder, water soluble, water suspendible are in use. The developer may be applied by spraying, complete immersion of specimen in containerThe developer may be applied by spraying, complete immersion of specimen in container Fig. Application of Developer 10 College code Hashmukh Goswami College of Engineering, Vahelal

This method is used for materials which can This method is used for materials which can be magnetized easily, i.e. ferromagnetic be magnetized easily, i.e. ferromagnetic materials include iron, nickel, and cobalt alloys and many of pricipitation hardening steels. and many of pricipitation hardening steels. Magnetic Particle Testing 11 College code Hashmukh Goswami College of Engineering, Vahelal

Process of MPT : Magnetic particle testing consists of magnetizing the component, sprinking the magnetic powder particles on to the surface of the same and inspecting defect.Magnetic particle testing consists of magnetizing the component, sprinking the magnetic powder particles on to the surface of the same and inspecting defect. To get maximum sensitivity, magnetizing flux lines should be oriented 90 degree to the defect.To get maximum sensitivity, magnetizing flux lines should be oriented 90 degree to the defect. Method for magnetizing the components are given below:Method for magnetizing the components are given below: 12 College code Hashmukh Goswami College of Engineering, Vahelal

Method for magnetizing the components are given below: 1.Residual method 2.Continuous method 3.Wet method 4.Dry method 5.Longitudinal magnetization method 6.Circular magnetization method 7.Magnetization using DC, AC or HW AC 13 College code Hashmukh Goswami College of Engineering, Vahelal

Advantages of MPT : Principally and relatively simple methodPrincipally and relatively simple method Economical and easy to performEconomical and easy to perform Portable for field testingPortable for field testing Fast for production testingFast for production testing Easy revel/disclose small surface or sub-surface flaws or cracks which may be tight.Easy revel/disclose small surface or sub-surface flaws or cracks which may be tight. 14 College code Hashmukh Goswami College of Engineering, Vahelal

Definition : An not method that utilizes x-rays or gamma radiation to detect discontinuities in material, and to present their image on recording medium.An not method that utilizes x-rays or gamma radiation to detect discontinuities in material, and to present their image on recording medium. Radiography is a nondestructive testing method to inspect the hidden flaws within the materials by using the short wavelength electromagnetic radiations by utilizing their high penetrating power.Radiography is a nondestructive testing method to inspect the hidden flaws within the materials by using the short wavelength electromagnetic radiations by utilizing their high penetrating power. x-rays or gamma rays can be used to get source of radiation.x-rays or gamma rays can be used to get source of radiation. Radiography 15 College code Hashmukh Goswami College of Engineering, Vahelal

Applications of radiography : Radiography can be used to inspect most types of solid material including both ferrous and nonferrous alloys.Radiography can be used to inspect most types of solid material including both ferrous and nonferrous alloys. This method is extensively used for their critical testing to ensure a flaw-free object for casting, weldments and forgings.This method is extensively used for their critical testing to ensure a flaw-free object for casting, weldments and forgings. The methods have limitation to inspect semiconductor devices.The methods have limitation to inspect semiconductor devices. 16 College code Hashmukh Goswami College of Engineering, Vahelal

Advantages of radiography The method is not limited by type of material or density.The method is not limited by type of material or density. It can inspect assembled components.It can inspect assembled components. It does not required any surface preparation.It does not required any surface preparation. The technique can give good response to variation in thickness, corrosion, voids, cracks, or change in material density.The technique can give good response to variation in thickness, corrosion, voids, cracks, or change in material density. Both surface and subsurface defects can be detected.Both surface and subsurface defects can be detected. It gives indications immediately.It gives indications immediately. 17 College code Hashmukh Goswami College of Engineering, Vahelal

Limitations of radiograph for x-rays A special training is to be given to the operator before the testing.A special training is to be given to the operator before the testing. As the radiation used are hazardous, care must be taken for safety against highly intense radiation.As the radiation used are hazardous, care must be taken for safety against highly intense radiation. In most cases, access to sides of the components is required for a correct result.In most cases, access to sides of the components is required for a correct result. A power source is required.A power source is required. The initial cost for equipment is very high.The initial cost for equipment is very high. For determining the depth of a flaw, many exposures from various angles are necessary.For determining the depth of a flaw, many exposures from various angles are necessary. 18 College code Hashmukh Goswami College of Engineering, Vahelal

Limitations for gamma rays : Only one energy level per source is possible.Only one energy level per source is possible. There is always chance for radiation hazard.There is always chance for radiation hazard. Like x-ray radiography, a trained technician would be required.Like x-ray radiography, a trained technician would be required. The gamma ray source loses strength continuously.The gamma ray source loses strength continuously. 19 College code Hashmukh Goswami College of Engineering, Vahelal

The use of sound waves to determine defects is very ancient method.The use of sound waves to determine defects is very ancient method. Ultrasonic testing is a modified method utilizing sound waves above the audible range with a frequency of 1 to 5 million Hz.Ultrasonic testing is a modified method utilizing sound waves above the audible range with a frequency of 1 to 5 million Hz. It is a fast, reliable non destructive testing method which penetrate metal, liquid, and many other material.It is a fast, reliable non destructive testing method which penetrate metal, liquid, and many other material. The ultrasonic sound waves are usually produced by piezoelectric material. these materials undergo a change in physical dimension when subjected to an electric field.The ultrasonic sound waves are usually produced by piezoelectric material. these materials undergo a change in physical dimension when subjected to an electric field. Such a conversion of electric energy to mechanical energy is known as piezoelectric effect.Such a conversion of electric energy to mechanical energy is known as piezoelectric effect. Quartz is a commonly used piezoelectric material.Quartz is a commonly used piezoelectric material. Ultrasonic Testing 20 College code Hashmukh Goswami College of Engineering, Vahelal

Imaging modes of ultrasonic imaging (a) A-scan C-scan B-scan 21 College code Hashmukh Goswami College of Engineering, Vahelal

Equipment for ultrasonic testing : The equipment consists of an electronic consol that the oscillator circuit, timer circuit and a display unit.The equipment consists of an electronic consol that the oscillator circuit, timer circuit and a display unit. The consol is connected through cable to the probe.The consol is connected through cable to the probe. The piezoelectric crustal of the probe converts electrical signals to mechanical waves and vice-versa.The piezoelectric crustal of the probe converts electrical signals to mechanical waves and vice-versa. The probe is used to scan the area to be inspected on the surface of the components.The probe is used to scan the area to be inspected on the surface of the components. 22 College code Hashmukh Goswami College of Engineering, Vahelal

Advantages of ultrasonic testing : Only one accessible surface of the part is needed for testing.Only one accessible surface of the part is needed for testing. At a time very large section thickness can be tested due to more penetrating power.At a time very large section thickness can be tested due to more penetrating power. It is applicable to linear & non-linear components, and surface as well as internal defects can be detected the best.It is applicable to linear & non-linear components, and surface as well as internal defects can be detected the best. The method is relatively portable, highly accurate & sensitive as compared to radiography.The method is relatively portable, highly accurate & sensitive as compared to radiography. As the speed of operation is high, results can be obtained immediately.As the speed of operation is high, results can be obtained immediately. The cost is low as compared to other volumetric test methods.The cost is low as compared to other volumetric test methods. Can be automated for a particular application.Can be automated for a particular application. 23 College code Hashmukh Goswami College of Engineering, Vahelal

Eddy currents are defined as oscillating electrical currents induced in a conductive material by an alternating magnetic field due to electromagnetic induction.Eddy currents are defined as oscillating electrical currents induced in a conductive material by an alternating magnetic field due to electromagnetic induction. Application of ECT : ECT can be used for weld inspection, conductivity testing, surface inspection, corrosion detection and tubing inspection.ECT can be used for weld inspection, conductivity testing, surface inspection, corrosion detection and tubing inspection. It can be used for conductivity, hardness, strength, heat treatments, dimensions, discontinuity, coating thickness etc.It can be used for conductivity, hardness, strength, heat treatments, dimensions, discontinuity, coating thickness etc. On line testing of wires, rods & tubes is possible with wide range of diameters.On line testing of wires, rods & tubes is possible with wide range of diameters. Eddy Current Testing 24 College code Hashmukh Goswami College of Engineering, Vahelal

 Following two laws must be known to ECT : Faraday’s law Oersted law Faraday’s law : “if a magnetic field cuts a conductor or if a conductor cuts a magnetic field, an electrical current flow through the conductor when closed path is provided.” Oersted law : “a magnetic flux exists around a coil carrying current proportional to number of turns in coil & the value of current.” 25 College code Hashmukh Goswami College of Engineering, Vahelal

 Procedure of eddy current testing : Based on application, variation techniques are used.Based on application, variation techniques are used. In probe method, a single probe is moved over the surface of the component for scanning.In probe method, a single probe is moved over the surface of the component for scanning. Properties such as hardness, alloy composition, chemical purity, and heat condition influence the magnetic field and may be measured directly by a single probe.Properties such as hardness, alloy composition, chemical purity, and heat condition influence the magnetic field and may be measured directly by a single probe. 26 College code Hashmukh Goswami College of Engineering, Vahelal

Advantages of ECT : Its sensitivity is relatively good for small parts usually by using point probe with very small diameter.Its sensitivity is relatively good for small parts usually by using point probe with very small diameter. It requires minimum part preparation before testing.It requires minimum part preparation before testing. Test results can be obtained immediately and the method is non- contact type.Test results can be obtained immediately and the method is non- contact type. Equipment is portable, so field inspection can be carried out easily.Equipment is portable, so field inspection can be carried out easily. The method can be used for complex shapes & sizes of conductive materials.The method can be used for complex shapes & sizes of conductive materials. 27 College code Hashmukh Goswami College of Engineering, Vahelal

Refrence  The Collaboration for NDT Education ( )  The American Society for Nondestructive Testing ( ) 28 College code Hashmukh Goswami College of Engineering, Vahelal

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