Pràctiques de Materials_DAVID FENOLLAR

David Fenollar Belda

01/04/2014

Pràctiques de Materials 0

Assajos No Destructius (NDT)

01/04/2014 EPS Alcoi David Fenollar Belda

David Fenollar Belda

01/04/2014

Contingut Pràctica 1: Líquids Penetrants .................................................................................................... 2 Resum .................................................................................................................................... .................................................................................................................................... 2 Introducció ............................................................................................................................ 2 Objectius ............................................................ ............................................................................................................................... ................................................................... 2 1

Fase Experimental ................................................................................................................. ................................................................................................................. 2 Resultats i Discussió .............................................................................................................. .............................................................................................................. 6 Conclusions .................................................................... ........................................................................................................................... ....................................................... 7 Practice 2: Ultrasounds................................................................... ............................................................................................................... ............................................ 8 Abstract ................................................................................................................................. ................................................................................................................................. 8 Introduction ................................................................... .......................................................................................................................... ....................................................... 8 Objectives .............................................................................................................................. .............................................................................................................................. 8 Experimental ......................................................................................................................... 9 Results and Discussion ........................................................................................................ ........................................................................................................ 13 Conclusions .................................................................... ......................................................................................................................... ..................................................... 13 Practice 3: Magnetic Particles .................................................................................................. 14 Abstract ............................................................................................................................... ............................................................................................................................... 14 Introduction ................................................................... ........................................................................................................................ ..................................................... 14 Objectives ............................................................................................................................ ............................................................................................................................ 14 Experimental ....................................................................................................................... 14 Results and Discussion ........................................................................................................ ........................................................................................................ 21 Conclusions .................................................................... ......................................................................................................................... ..................................................... 21 Practice 4: Infrared Camera .................................................................................. ...................................................................................................... .................... 22 Abstract ............................................................................................................................... ............................................................................................................................... 22 Introduction ................................................................... ........................................................................................................................ ..................................................... 22 Objectives ............................................................................................................................ ............................................................................................................................ 22 Experimental ....................................................................................................................... 22 Results and Discussion ........................................................................................................ ........................................................................................................ 23 Conclusions .................................................................... ........................................................................................................................... ....................................................... 2

David Fenollar Belda

01/04/2014

Pràcticà 1: Líquids Penetrànts Resum En la pràctica següent el que es realitzarà la comprovació de les impureses o esquerdes d’una peça escollida degudes a l'ús d'aquesta en servici. Es farà servir el mètode dels líquids 2

penetrants, un mètode que es troba dins dels assajos no destructius per a la detecció d’errades superficials en peces .

Introducció Es planteja una peça (la de la fotografia adjunta) per a determinar els seu estat després d'haver estat en servici durant un temps (també es pot donar el cas d'una peça durant el procés de producció). Considerant que es una peça que ha de continuar en servici posteriorment a l’anàlisi, es realitzarà un assaig no destructiu (NDT) pel qual es determinaran les errades o impureses

d'aquesta sense haver d'afectar a les seues propietats. En concret es realitzarà l’assaig  de líquids penetrants, ja que es un assaig barat, en el que no cal un gran equipament ni fonts d’energia i amb molt bons resultats. Aquest es un assaig basat en el principi de capil·laritat dels líquids .

Objectius Aconseguir la visualització de les impureses i errades en una peça amb el mètode, d’assajos no destructius, dels líquids penetrants.

Fase Experimental Materials: o

Dissolvent orgànic potent

o

Cetona

o

Paper higiènic o drap de

Dissolvent

cotó o

Líquid penetrant

o

Pols reveladora

o

Elements de protecció

Liquid penetrant

organic

(careta, guants, bata i si cal ulleres)

Revelant Netejant menys agressiu

David Fenollar Belda

01/04/2014

Desenvolupament Experimental: 

Neteja: és la primera fase, amb la qual s’eliminen grasses i òxids procedents del servici

del material o bé del procés de producció de la peça. Aquesta etapa es la més important ja que s’han d’eliminar les restes d’impureses que puguem tenir en les esquerdes o en les imperfeccions. Normalment per a aquesta fase s’utilitzen dissolvents orgànics ja que normalment les peces aquestes peces contenen restes de 3

materials orgànics. S’haurien d’utilitzar raspalls o altre tipus de dissolvents en el cas de

tenir òxids o altre tipus de brutesa. La peça quedarà com segueix després d’haver -la netejat amb el dissolvent i un drap.



Aplicació del líquid penetrant: es tracta d’aplicar una fina capa de líquid (suficient per

a que penetri) bé per deposició o per submersió de la peça en el mateix. Aquests líquids han d’acomplir una sèrie de condicions que els faran aptes per a aquesta

aplicació (com baixa volatilitat, facilitat de penetració, facilitat de neteja, o baixa toxicitat i que ser químicament inert, entre altres). Després de l’aplicació es deixarà al

voltant de 20 minuts (depenent de la morfologia de la peça) per afavorir la correcta penetració d’aquest a totes les impureses i esquerdes superficials. S’ha  de tenir en compte que la utilització d’un o altre penetrant dependrà de la

morfologia i el material de la peça a analitzar, ja que un material químicament inert (orgànic) no danyarà el material mentre que un en dissolució aquosa si es tracta de materials com l’alumini si que pot ocasionar xicotets punts d’oxidació que a la llarga afectaran de forma negativa la peça. En aquest cas s’ha utilitzat un dissolvent orgànic amb color roig intens com el que apareix a l a fotografia, i com que es tracta d’una peça d’una geometria molt senzilla doncs no cal fer l’espera de 20 minuts, però si suficients

per a deixar penetrar el líquid.

David Fenollar Belda

01/04/2014

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

Neteja del líquid de la superfície:  aquesta neteja ha de ser el menys agressiva

possible, ja que no s’ha d’eliminar el líquid penetrant dels llocs a analitzar, per tant cal fer-la amb compte, utilitzant un drap i un dissolvent poc agressiu com la cetona. Si es tractés d’un líquid en dissolució aquosa caldria eliminar-lo mitjançant un xorro d’aigua

aplicat amb certa inclinació perquè no incideixi directament en l’esquerda .

David Fenollar Belda

01/04/2014

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CETONA



Aplicació del revelador: Aquesta etapa és molt important realitzar-la correctament, ja

que de la correcta realització depèn la trobada de les imperfeccions buscades. En aquesta etapa s’aplica una capa de pols blanca per a facilitar , pel fenomen de la tensió superficial, l’eixida  del líquid aplicat amb anterioritat i que després de netejar-lo ja

només en queda en les esquerdes. Cal realitzar-la correctament perquè si es diposita excessiva pols reveladora en la superfície de la peça aleshores no apareixeran les esquerdes xicotetes, mentre que si no es diposita la suficient aleshores una esquerda gran i moltes xicotetes tacarien de la mateixa forma la superfície de la pols. Es poden encontrar dos tipus de reveladors: un en el que la pols es troba en dissolució, per la qual cosa s’evita la utilització d’elements de protecció com caretes, i un altre que es

tracta de pols seca, per al qual cosa cal la protecció, be amb caretes o be realitzant el procediment en una campana extractora.

2 Aplicació

de la pols reveladora

1Vista

de la peça una vegada aplicada aquesta pols

David Fenollar Belda

01/04/2014

Una vegada aplicat el revelador, el qual es tractava d’una pols en dissolució, s’observa com queda la peça amb una capa blanca. A continuació cal deixar uns minuts per a que el líquid penetrant puge cap a la superfície de la pols i el qual quedarà com veiem en les fotos inferiors:

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4 Cara

A de la peça després d'aplicar el revelant 

3 Cara

B de la peça després d'aplicar el revelant 

La inspecció de la peça s’ha fet  baix llum natural, ja que el líquid penetrant escollit no es tracta d’un líquid fluorescent, de la segona forma s’hauria hagut d’inspeccionar-la amb llum

ultraviolada. 

Neteja de la peça:  Aquest pas és molt important per a garantir la continuïtat de la

peça en el cas en què la vulguem tornar a fer servir en la funció que feia, ja que en aquest pas hem d’intentar eliminar totes les restes de dissolvent ja que si es troba en

dissolució aquosa tenim el perill que ens apareguin oxidacions puntuals que faran de detonant per a l’aparició de noves imperfeccions que ens poden trencar la peça.

En el nostre cas hem escollit líquids orgànics, i per aquesta raó no existeix aquest perill, però encara així hem de fer una correcta neteja amb dissolvents orgànics (nostre cas) i amb draps per a que puguem tornar a fer funcionar la peça i no tenir problemes a mitjan termini.

Resultats i Discussió Com anteriorment es comenta, els resultats han segut, per una banda s’ha obtingut la cara A de la peça amb una xicoteta esquerda a la part dreta en el cantó. En la cara B el que s’ha pogut observar son diverses esquerdes, en les que cal destacar una que es la que ix de la par inferior de la peça cap amunt i que es tracta de la més gran o més profunda. No se sap baix quins esforços estava treballant aquesta peça però el que si se sap es que la majoria de fallades i esquerdes son degudes a treballs sota esforços de fatiga, per aquesta raó es molt probable que aquesta peça treballés sota aquest esforç a més de la forma de les esquerdes, esquerdes continues pròpies de fallades per fatiga . Encara que també es pot trobar que es tracte d’imperfeccions degudes al procés de producció de la mateixa peça, encara que no és probable pel desgast d’aquesta .

David Fenollar Belda

01/04/2014

Conclusions Tot i que el sistema utilitzat no indica de forma quantitativa els resultats es un procés ràpid i sobretot és un procés barat, amb el qual es pot saber si la peça presenta alguna esquerda o alguna impuresa superficial, no se sabrà mai els problemes que presenta a nivell intern, els quals els s’hauran d’observar amb altres processos. 7

Aquesta darrera limitació és important a l ’hora d’aplicar el mètode, ja que no es podrà aplicar a materials porosos, perquè no donaran cap informació. Com que en aquest cas es tractava d’acer, aleshores s’han   visualitzat les esquerdes que contenia la peça, així com també s’ha estimat de forma aproximada la magnitud d’aquestes segons la quantitat de líquid que ha eixit a l’exterior. Per tant es pot afirmar que els nostres

objectius han quedat acomplerts, aconsegui nt visualitzar l’estat superficial de la peça d’estudi . A més, s’ha aconseguit la manipulació i l’aplicació correcta d’aquesta tècnica per part de l’alumne així com observar els avantatges i inconvenients d’usar -la, ja que es tracta d’una

tècnica molt senzilla d’aplicar i ràpida i a més no es calen grans aparells costosos ni grans espais per aplicar-la, encara que no es pot aplicar a tot tipus de materials així com tampoc detecta tot tipus d’imperfeccions, sinó només les de la superfície.

.

David Fenollar Belda

01/04/2014

Pràctice 2: Ultràsounds  Abstract An ultrasonic non-destructive method is used to determinate possible cracks and failures in different pieces, impossible to find using the last method (penetrant liquids). The aim of this 8

work is explain this method. Now, the method and the process to find hide imperfections under the surface is going to be explained.

Introduction To determinate the position and the deep of different slits in a piece, an ultrasound technique is used. Here there is a piece in which have made some subsurface slits. The goal of this article is to find it and determine the height of this using ultrasounds. Ultrasounds is a technique included on the non-destructive tests, based on a piezoelectric material who emits and receive sound waves which are converted in a potential difference, this is observed on a screen of cathodic rays tube. Depending on the received signal, it will be possible to determine both the site and the dimensions of the crack (slits in our case). Before the inspection of the working piece a calibration of the machine is needed. This process consists on inspecting a normalized piece knowing the results and adapt the cathodic rays tube screen to see the result we have

5. Calibration piece and cathodic ray tube machine

to see (this is the main step we have to do when we have to inspect a piece). The process of calibrating the machine is possible to made with 3 kinds of probes. The first one is the normal probe, which sends the ultrasonic wave normal to the surface piece. The second one is the angular probe, that sends the wave forming a specific angle between probe and surface piece. The last one is normal and two glasses, first glass is used to send the wave and second to receive it. Behind the piezoelectric material we have a wave deadening to avoid the vibration of this.

Objectives Finding the hided imperfections under the surface of a number of pieces and indicate the approximate height of this using the non-destructive test called Ultrasounds.

David Fenollar Belda

01/04/2014

Experimental Materials

In the experimental phase of this pieces test, we are going to need the following materials:

9

o

Probe

o

Cathodic rays tube machine

o

Calibration piece

o

Normative relating to Ultrasonic NDT

o

Vaseline and spreader

o

Pen

o

A calliper gauge

Calliper Gauge Normative

Cathodic rays tube machine

Probes and Pencil Vaseline and Spreader

Calibrating Piece Testing Piece

Spreader 6. Material used to do the ultrasound test

David Fenollar Belda

01/04/2014

Experimental

The first step, like it was commented previously, is to calibrate the machine which allow us to view the changing of material detected by the probe. Firstly the background noise of the machine must to be detected. Then it’s going to adjust the screen rank until convert the noise in a straight line (in the 10

screen). Now it’s time to   connect the probe and put the double glass mode (or any other), taking the calibrating piece and known the whole measures and that this piece hasn’t got any imperfection, it’s

known the results we have to view in the cathodic

screen

depending

on

the

7. Adjusting the noise

position of the probe. Firstly, the Vaseline is put on the piece and then the probe will be put on the piece to verify and adjust the measures of the screen. If the expected results in the screen are viewed (according to the normative), the screen axes have to be adjusted to our results (because we need an impulse whenever the screen mark the piece thickness and we have to adjust the dimension of the screen to obtain this results, because if it is not adjusted we are obtaining a peak each 2 times the piece thickness), and then we are able to begin the Testing Piece test.

Probe and Vaselin

Calibrating Piece

8. Calibrating the cathodic tube machine

David Fenollar Belda

01/04/2014

The machine calibration is needed because it’s  needed to know if the

probe is worn down or if it is OK (the screen

parameters

have

to

be

adjusted differently in order to have the same final results according to the 11

normative). This are the expected results according to the normative UNE:

Now, the test piece is going to be tested. At first it’s necessary to measure the piece thickness to

Alarm

Peak

know which is the maximum

Peak

distance between 2 consecutive impulses, after that, vaseline is put on the piece surface, then it will be able to put the probe on the surface and start testing (we put vaseline between surface and probe

to

avoid

the

wearing

down). Now the probe is put

Surface

9. One peak that shows an imperfection

through the whole piece surface, looking to the cathodic tube machine screen waiting for a peak before the peak which indicates the other surface (in the machine, we have the option to put an alarm when a peak appears in a delimited zone that we have delimited before). Now some peak not hope is being detected and this could be measured by looking to the screen and moving the probe in all directions being sure that the peak is still in the screen. While the peak is in the screen it means that the imperfection is still under the surface, so it’s possible to mark the beginning and the finish of the peak and we will have the dimensions of the imperfection. Here we have a picture showing the results:

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01/04/2014

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10. Tested piece and marks of the crack

Would have to be repeated this process along the surface to verify that the piece is free of imperfections. When it’s finished with the normal probe, it’s necessary to test the piece with

an angular probe because may have angular imperfections or cracks, not possible to detect with a normal probe like shows the following picture:

11. Angular and normal probe comparison

*If it’s going to test melting, it’s recommended to do this wi th an angular probe. In order to avoid the wrong indications, it’s necessary   to be careful with the test and do all steps according to the normative. It’s needed to be careful with: electrical interferences or different kinds of parasites due to the probe or the piece.

David Fenollar Belda

01/04/2014

Results and Discussion As we can observe in picture number 11, a crack has been detected and we have been able to measure this. The objective of the article has been done, so it´s possible to conclude that this test allows us to test materials which are working with and needs a review, or materials which are manufacturing and needs a quality control. 13

Conclusions This is a NDT technique that allows us not only to find the imperfection but also measure it. In addition, this technique is also used to evaluate the corrosion, chemical and physical properties and measure the thickness. Although ultrasounds is an expensive equipment technique (compared with penetrating liquids), this is very useful to m easure the dimensions of the imperfection (this feature is not in the penetrating liquids, in which you aren’t able to measure imperfections). But you have to

choose the method carefully because there is so much parameters that makes viable the method (accessibility, shape, accuracy…).

Besides, there has been achieved another objective. This objective is to get freedom with the method like an expert of non-destructive tests. So, in conclusion, there are some economic advantages to use NDT methods to evaluate imperfections of pieces in use and pieces that are in the productive process. We can say that ultrasounds is one of the best methods because gives us an accuracy information.

David Fenollar Belda

01/04/2014

Pràctice 3: Màgnetic Pàrticles  Abstract The aim of this work is to determinate the cracks or imperfection both on the surface and subsurface (not under 20mm) on magnetic pieces. This is going to be possible using the NDT 14

called magnetic particles. This test consists on magnetize the piece and then apply a quantity of magnetic particles which are going to be deposited most of them in the crack.

Introduction Magnetism is a physical phenomenon which allows objects to attract or repulse by a magnetic field. Magnetic particles is a method based on the principle that if an object is magnetized, their imperfections behave as diamagnetic and expulse the field lines. This cause an accumulation of particles, magnetic powder, which are susceptible to be affected by the magnetic field in the imperfection zone. This is the principle used by the magnetic particles method, which allow us to find imperfections on pieces that can be affected by the magnetic field, ferromagnetic materials. This technique is used only to find surface and subsurface imperfections not under 20mm because these imperfections don’t produce enough field deviation to affect the surface.

Objectives Finding the surface and subsurface imperfections and cracks (up to 20 mm) using the magnetic particles method, and get skill using this method.

Experimental Spray

Materials o

Magnetic yoke

o

Dry powder

o

Spray powder

o

Spray ultraviolet powder

o

Ultraviolet light

o

Contrast lacquer

o

Ethanol

o

Permanent magnet

Spray powder

Dry powder

Contrast

ultraviolet

lacquer

powder

David Fenollar Belda

01/04/2014

Magnetic yoke

15 Anode and catode Pieces

Permanent magnet

Experimental

The machine used for this kind of test is a magnetic yoke, this is a machine which is composed by 2 parts. The first one is the electric field generator. The second one is the anode and the cathode which is used to apply an electric field to the piece so that to create a magnetic permanent field on this. This test is based on 3 basic phases: magnetization, particles application and demagnetization. All phases is going to be explained then. First of all is needed to know the different way of magnetizing the piece depending on the orientation of the particles we hope found. The best way to magnetizing the piece is the one which makes more of the magnetic field lines pass through the imperfection. Because is not known the situation of the imperfection, is advisable magnetize the piece in all directions if it is big. The case of study is about small pieces, is for this reason that is not going to do an all directions magnetization.

David Fenollar Belda

01/04/2014

Then, the next step is magnetize the piece. To do this step is needed the magnetic yoke. The magnetization of the piece have to be firstly in one direction and then in others to find all kinds and orientation of the imperfections. The magnetization is done with the magnetic yoke, putting both anode and cathode one in the opposite site of other on the piece. Then an electric field is applied. As a result of the electric field, a magnetic field is generated inside the piece and it will allow the magnetic particles to show the imperfections. 16

The power of the electric field is measured as a percent. In the case of study, it’s going to find

the percent of the total electric field looking at both the anode and cathode, searching for a spark. When a spark is viewed, it indicates the electric field is enough. The next step is the application of the magnetic particles. Magnetic particles can be found in 3 types: dry magnetic particles, wet m.p. and ultraviolet m.p. Usually wet m.p. are dissolved on an organic solution or water solution (in the water solution there is a problem related on the temperatures). One of the objectives of this article is determine advantages and disadvantages of using wet method in comparison with dry method. The application of the magnetic particles is very easy, only needs to spread the particles above the piece (wet particles will be spread in spray). When the particles are sloped on the piece, you must move the piece to allow the particles to spread correctly. The particles will take place on the magnetic field distortions caused by the imperfections. The following picture shows the crowding of the particles on the imperfections showing it:

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12. Firstly sloping the particles. Finally the piece with the particles showing the imperfections before shaking the piece.

The way to preceed with wet particles is the same, when the piece is magnetized the only thing is needed is to spray the wet particles above the piece. The result with wet particles is this:

13. Piece with wet magnetic particles.

The result of wet particles is easily to view, the cracks are viewed at the moment, without waiting. It may be possible at first the cr acks can’t be viewed, in this case is needed shake the piece.

David Fenollar Belda

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The last variation of the method is to use ultraviolet particles, this particles becomes yellow when the ultraviolet light influence it. This is a good method because is not needed the contrast liquid, and is observed in the images below that the cracks are perfectly viewed.

20

Finally the last step is demagnetizing the piece. This step will be done with the magnetic yoke, the only thing to do is magnetizing the piece with less power than 60%, downgrading about 10% per time, to finish in 0%. Then the piece will be demagnetized. Another way to demagnetize the piece is heating it to get the Curie temperature, which gives to the material the beginning properties.

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01/04/2014

Results and Discussion The results are easy to view if the pictures above are looked. The cracks and imperfections in the pieces are looked on all cases, wet, dry and ultraviolet. There are some features in the magnetic particles that make it suitable to this test. For example the different sizes that is good to make the biggest lug the smallest. 21

Another feature, now in the piece, which are good for applying the test is the high retentivity of it (because are steel), which endures very good the magnetic field and are very good to magnetize. To view imperfections with wet and dry methods, a contrast applied above the piece is needed (this contrast normally is withe). This contrast is put before the magnetic particles and allows the expert to tell apart the magnetic particles. This contrast is usually given in spray format. If it isn’t possible to apply the spray contrast, ultraviolet particles is a very good option because

when the ultraviolet light is applied to the particles, it becomes yellow and it are very easy to tell apart from the piece. If the saturation power are exceeded all particles will be stuck to the piece surface and it will be impossible to determine where the imperfections are.

Conclusions This is a technique which complements the penetrant liquids method, applicable in ferromagnetic materials, because this technique works under the surface (up to 20mm). The first objective of this work is done, this is the observation of surface and subsurface cracks, as it can be observed in the picture number 12 and 13, and is also easy to conclude that in dark pieces (pieces which are not applied the contrast lacquer) is better to use ultraviolet particles, otherwise it wouldn’t able to view the magnetic particles shape recreating the crack.

Another objective not included in the paragraph ‘objectives’, but not less important is to find the advantages and disadvantages of using the wet or dry method. It can be observed in the wet method the easiest movements of the particles as well as a quick evaporation of the liquid. The dry method is better in so far as the clean of the piece is easier. Finally, to find imperfections inside a cylindrical piece (larger and more thickness than ours), the better way to magnetize this will be a conductive bar (cooper is the most used), and generating an electric field inside of the bar will generate a magnetic field in the inside surface of the tube.

David Fenollar Belda

01/04/2014

Pràctice 4: Infràred Càmerà  Abstract The aim of this work is to find the manufacturing imperfections and cracks in metal pieces, which are performing and are going to continue performing after the test. Many times in 22

industries is needed testing a piece which are performing, and will continue performing after the test if the failure are not big. To achieve this, non-destructive test are needed. There are many kinds of NDT, which are applicable to a lot of pieces and materials. Also there are some tests which are restricted to iron materials or non-porous materials. In this work is going to use infrared camera (belonging to NDT).

Introduction The infrared camera test is based on the different conduction of the heat flow obtained depending on the material. Mainly the imperfections in pieces are air, but also titanium or aluminium or other solid materials are found on iron pieces. The property of different materials to conduce heat makes each material to have a different cooling. There are 2 kinds of infrared thermography: firstly passive thermography consists on analyse the different behaviour of the cracks or imperfections without an external heating or cooling. Secondly, active thermography is based on the previous heating of the piece in an oven, or cooling it on a fridge. Belonging to the active thermography, there are 3 different kinds of heating the piece: pulse, step heating and lock-in. Then while the piece are cooling, the infrared camera take the different cooling of the materials in the piece. In the case of this study, is going to use the active method of thermography camera to inspect the imperfections of the piece.

Objectives In this work is going to analyse the imperfections of an iron piece using the infrared camera test belonging to non-destructive test.

Experimental Materials 

Infrared camera



Oven



Pincers

David Fenollar Belda

01/04/2014

Experimental

As it is aforementioned, the method which is going to be used in this work is active thermography. This method consists on heating the piece before the thermic observation. The temperature used to heat the piece is 160ºC in a laboratory oven. Then the piece is removed from the oven and is put in front of the infrared camera. While the piece is cooling down, the camera is having a shoot every 10 seconds because is the way to view the evolution of the 23

cooling down. Finally with the camera software, we are going to be able to know the different temperatures with the different thermic images, as is viewed below in the results. Then, with the infrared camera, is going to view the different facilities which can be inspected by viewing the heat. This facilities are e.g. the distribution panel or the water heater. With the observation of this, is viewed the facilities which consumes more power and if there are any facility with overpower due to a wrong working.

Results and Discussion There is the test piece which have been heated and cooled down. In the image below it is viewed the infrared camera which records the piece while it is cooling down. Moreover is viewed how the picture in the camera screen is a thermic image of the piece.

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01/04/2014

In the image below is viewed the different temperatures on the surface of the testing piece, including the zones composed by air which have a lower cooling down. With the camera software is possible to create tables of points, lines or areas indicating the different temperatures like the tables below. Also is possible to create graphics showing the different temperature of the surface or how much zones are with the same temperatures. All kind of information is showed below: 24

Spot analysis

Value

SP01Temperature

113.0°C

SP01Emissivity

0.85

SP02Temperature

68.6°C

SP02Emissivity

0.85

SP03Temperature

Line analysis

Value

Line01Max

112.6°C

Line01Min

25.4°C

Line01Average

64.7°C

72.5°C

Line01Distance

10.0m

SP03Emissivity

0.85

Line02Max

113.9°C

SP04Temperature

100.4°C

Line02Min

25.9°C

SP04Emissivity

0.85

Line02Average

64.2°C

SP05Temperature

58.4°C Line02Distance

10.0m

SP05Emissivity

0.85

David Fenollar Belda

01/04/2014

1

Area analysis

Value

Area01Max

125.5°C

Area01Min

25.4°C

Area01Average

63.9°C

There are some advantages and disadvantages on this method. On the one hand, this method is quickly and there is not needed to touch the piece. Also this technique allows the expert to find imperfections under the surface, is easy to translate the results and is applicable to a big kind of materials. This technique is not dangerous and is possible to inspect big and small zones depending on the needed. On the other hand there are some drawbacks which makes the technique not recommended depending on the situations. E.g. if the imperfection is far away from the surface, the camera is not going to detect it. If the material of the imperfection have a same emissivity that the piece material, this imperfection is not going to be viewed on the camera.

David Fenollar Belda

01/04/2014

Conclusions As is viewed on the picture below, the zones which not contains steel have a different cooling down. It means that the zones with imperfections (which are constituted by air) are more hot than the zones composed by steel.

2

Thereby the objectives of this work are accomplished. Firstly we viewed the different cooling down in the imperfections and then with the inspection of the different facilities were able to take skill with the using of the infrared camera.