SIST EN 12681-1:2018
(Main)Founding - Radiographic testing - Part 1: Film techniques
Founding - Radiographic testing - Part 1: Film techniques
This European Standard gives specific procedures for industrial X ray and gamma radiography for discontinuity detection purposes, using NDT (Non-destructive testing) film techniques. This part of EN 12681 specifies the requirements for film radiographic testing of castings.
Films after exposure and processing become radiographs with different area of optical density. Radiographs are viewed and evaluated using industrial radiographic illuminators.
This part of EN 12681 describes the recommended procedure for the choice of operating condition selection and radiographic practice.
These procedures are applicable to castings produced by any casting process, especially for steel, cast iron, aluminium, cobalt, copper, magnesium, nickel, titanium, zinc and any alloys of them.
NOTE This European Standard complies with EN ISO 5579.
This part of this European Standard does not apply to:
- radiographic testing of castings for aerospace applications (see prEN 2002-21);
- radiographic testing of welded joints (see EN ISO 17636-1);
- digital radiography (see prEN 12681-2);
- radioscopy (see EN 13068, all parts).
Gießereiwesen - Durchstrahlungsprüfung - Teil 1: Filmtechniken
Diese Europäische Norm legt die besonderen Vorgehensweisen für die industrielle Durchstrahlungsprüfung mit Röntgen- und Gammastrahlen zum Nachweis von Ungänzen mit NDT-Filmtechniken (en: Non-destructive testing, NDT) fest. Dieser Teil von EN 12681 legt die Anforderungen an die Durchstrahlungsprüfung mit Filmen von Gussstücken fest.
Nach der Aufnahme und dem Entwickeln sind die Filme Durchstrahlungsbilder, die Bereiche unterschied-licher optischer Dichte aufweisen. Die Durchstrahlungsbilder werden mit Betrachtungsgeräten für die industrielle Radiographie betrachtet und bewertet.
Dieser Teil von EN 12681 legt die empfohlene Vorgehensweise für die Wahl der Betriebsbedingungen und der Durchstrahlungstechnik fest.
Diese Vorgehensweisen gelten für nach einem beliebigen Gießverfahren hergestellte Gussstücke, insbesondere aus Stahl, Gusseisen, Aluminium, Cobalt, Kupfer, Magnesium, Nickel, Titan, Zink und deren Legierungen.
ANMERKUNG Diese Europäische Norm berücksichtigt EN ISO 5579.
Dieser Teil der Europäischen Norm gilt nicht für:
die Durchstrahlungsprüfung von Gussstücken für Anwendungen in der Luft- und Raumfahrt (siehe prEN 2002-21);
die Durchstrahlungsprüfung von Schweißverbindungen (siehe EN ISO 17636-1);
die Durchstrahlungsprüfung mit digitalen Detektoren (siehe EN 12681-2);
die radioskopische Prüfung (siehe EN 13068, alle Teile).
Fonderie - Contrôle par radiographie - Partie 1 : Techniques à l'aide de films
La présente Norme européenne décrit les procédures spécifiques de radiographie industrielle au moyen
de rayons X et gamma, pour la détection de discontinuités, selon des techniques employant des films
radiographiques pour END (essais non destructifs). La présente partie de l'EN 12681 spécifie les
exigences relatives au contrôle par radiographie de pièces moulées à l'aide de films.
Les films, après exposition et traitement, deviennent des radiogrammes comportant des zones de
densité optique différente. Les radiogrammes sont examinés et évalués à l'aide de négatoscopes utilisés
en radiographie industrielle.
La présente partie de l'EN 12681 spécifie la procédure recommandée pour le choix des conditions
d'utilisation et la pratique radiographique.
Ces procédures sont applicables aux pièces moulées, fabriquées par tous les procédés de moulage,
particulièrement pour les aciers, les fontes, l'aluminium, le cobalt, le cuivre, le magnésium, le nickel, le
titane, le zinc et leurs alliages.
NOTE La présente Norme européenne tient compte de l'EN ISO 5579.
Cette partie de la présente Norme européenne ne s'applique pas :
— au contrôle par radiographie des pièces moulées pour applications aérospatiales (voir le
prEN 2002-21) ;
— au contrôle par radiographie des assemblages soudés (voir l'EN ISO 17636-1) ;
— à la radiographie à l'aide de détecteurs numériques (voir l'EN 12681-2) ;
— au contrôle par radioscopie (voir toutes les parties de l'EN 13068).
Livarstvo - Radiografsko preskušanje - 1. del: Filmske tehnike
Ta evropski standard določa posebne postopke za industrijsko radiografijo z rentgenskimi ali gama žarki za namene odkrivanja prekinitev na podlagi filmskih tehnik NDT (neporušitveno preskušanje). Ta del standarda EN 12681 določa zahteve za filmsko preskušanje ulitkov z radiografijo. Filmi po izpostavljenosti in obdelavi postanejo radiografske slike z različnimi območji optične gostote. Radiografske slike so pregledane in ovrednotene na podlagi industrijskih radiografskih osvetljevalcev. Ta del standarda EN 12681 opisuje priporočen postopek izbire pogojev delovanja in radiografske prakse. Ti postopki se uporabljajo za ulitke, ki nastanejo pri postopku litja, zlasti za jeklo, lito železo, aluminij, kobalt, baker, magnezij, nikelj, titan, cink in njihove zlitine. OPOMBA: Ta evropski standard je v skladu s standardom EN ISO 5579. Ta del tega evropskega standarda se ne uporablja za: – radiografsko preskušanje ulitkov za uporabo v vesoljskih plovilih (glej prEN 2002-21); – radiografsko preskušanje varjenih spojev (glej EN ISO 17636-1); – digitalno radiografijo (glej prEN 12681-2); – radioskopijo (glej EN 13068, vsi deli).
General Information
Relations
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Livarstvo - Radiografsko preskušanje - 1. del: Filmske tehnikeGießereiwesen - Durchstrahlungsprüfung - Teil 1: FilmtechnikenFonderie - Contrôle par radiographie - Partie 1 : Techniques à l'aide de filmsFounding - Radiographic testing - Part 1: Film techniques77.040.20Neporušitveno preskušanje kovinNon-destructive testing of metalsICS:Ta slovenski standard je istoveten z:EN 12681-1:2017SIST EN 12681-1:2018en,fr,de01-februar-2018SIST EN 12681-1:2018SLOVENSKI
STANDARDSIST EN 12681:20031DGRPHãþD
SIST EN 12681-1:2018
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 12681-1
November
t r s y ICS
y yä r v rä t r Supersedes EN
s t x z sã t r r uEnglish Version
Founding æ Radiographic testing æ Part
sã Film techniquesFonderie æ Contrôle par radiographie æ Partie
s ã Techniques à l 5aide de films
Gießereiwesen æ Durchstrahlungsprüfung æ Teil
sã Filmtechniken This European Standard was approved by CEN on
s x July
t r s yä
egulations which stipulate the conditions for giving this European Standard the status of a national standard without any alterationä Upætoædate lists and bibliographical references concerning such national standards may be obtained on application to the CENæCENELEC Management Centre or to any CEN memberä
translation under the responsibility of a CEN member into its own language and notified to the CENæCENELEC Management Centre has the same status as the official versionsä
CEN members are the national standards bodies of Austriaá Belgiumá Bulgariaá Croatiaá Cyprusá Czech Republicá Denmarká Estoniaá Finlandá Former Yugoslav Republic of Macedoniaá Franceá Germanyá Greeceá Hungaryá Icelandá Irelandá Italyá Latviaá Lithuaniaá Luxembourgá Maltaá Netherlandsá Norwayá Polandá Portugalá Romaniaá Serbiaá Slovakiaá Sloveniaá Spainá Swedená Switzerlandá Turkey and United Kingdomä
EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre:
Avenue Marnix 17,
B-1000 Brussels
9
t r s y CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Membersä Refä Noä EN
s t x z sæ sã t r s y ESIST EN 12681-1:2018
EN 12681-1:2017 (E) 2 Contents Page European foreword . 4 Introduction . 5 1 Scope . 6 2 Normative references . 6 3 Terms and definitions . 7 4 Symbols and abbreviations . 8 Table 1 — Symbols and abbreviations . 8 5 Classification of radiographic techniques . 9 6 General preparations and requirements . 9 6.1 General preparations . 9 6.1.1 Protection against ionizing radiation . 9 6.1.2 Surface preparation and stage of manufacture . 9 6.2 Agreements . 9 6.3 Personnel qualification . 10 7 Test arrangements . 10 7.1 General . 10 7.2 Single wall radiography of plane areas . 10 7.3 Single wall radiography of curved areas . 10 7.4 Double wall radiography of plane and curved areas . 10 7.5 Choice of test arrangements for complex geometries . 11 7.6 Acceptable test area dimensions . 11 8 Choice of tube voltage and radiation source . 16 8.1 X-ray devices up to 1 000 kV . 16 8.2 Other radiation sources . 17 9 Film systems and metal screens . 18 10 Reduction of scattered radiation . 20 10.1 Metal filters and collimators . 20 10.2 Interception of backscattered radiation. 20 11 Source-to-object distance . 20 12 Optical density D of radiograph . 23 13 Film processing and viewing . 23 13.1 Processing . 23 13.2 Film viewing conditions . 23 14 Techniques for increasing the covered thickness range . 23 14.1 General . 23 14.2 Multiple film technique . 24 14.3 Contrast decreasing by higher radiation energy . 25 14.4 Contrast decreasing by beam hardening . 25 14.5 Contrast decreasing by thickness equalization. 26 SIST EN 12681-1:2018
EN 12681-1:2017 (E) 3 15 Requirements on radiographs . 26 15.1 Identification of radiograph, test area, film position plan. 26 15.2 Marking of the test areas . 26 15.3 Overlap of films . 26 16 Verification of image quality . 26 17 Influence of crystalline structure . 27 18 Acceptance criteria . 27 18.1 General . 27 18.2 Severity levels . 27 18.3 Wall section zones . 27 19 Test report . 28 Annex A (normative)
Minimum image quality values . 30 Annex B (normative)
Severity levels for steel castings . 33 Annex C (normative)
Severity levels for cast iron castings . 36 Annex D (normative)
Severity levels for aluminium alloy and magnesium alloy castings . 39 Annex E (normative)
Severity levels for copper alloy castings . 43 Annex F (normative)
Severity levels for titanium and titanium alloy castings . 45 Annex G (informative)
Significant technical changes between this European Standard and the previous edition . 47 Bibliography . 48
SIST EN 12681-1:2018
EN 12681-1:2017 (E) 4 European foreword This document (EN 12681-1:2017) has been prepared by Technical Committee CEN/TC 190 “Foundry technology”, the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by May 2018, and conflicting national standards shall be withdrawn at the latest by May 2018. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 12681:2003. Within its programme of work, Technical Committee CEN/TC 190 requested CEN/TC 190/WG 10 “Testing for inner discontinuities”: — to revise EN 12681:2003 into EN 12681-1, Founding — Radiographic testing — Part 1: Film techniques; — and to prepare a further standard EN 12681-2, Founding — Radiographic testing — Part 2: Techniques with digital detectors Annex G covers the significant technical changes between this European Standard and EN 12681:2003. According to the CEN-CENELEC Internal Regulations, the national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. SIST EN 12681-1:2018
EN 12681-1:2017 (E) 5 Introduction Radiography can be used to detect internal discontinuities in a casting. The discontinuities can be gas holes, non-metallic inclusions, shrinkage, cracks, inserts or chills or inclusions that have lower or higher densities than the parent metal. This European Standard gives acceptance criteria through severity levels. SIST EN 12681-1:2018
EN 12681-1:2017 (E) 6 1 Scope This European Standard gives specific procedures for industrial X-ray and gamma radiography for discontinuity detection purposes, using NDT (Non-destructive testing) film techniques. This part of EN 12681 specifies the requirements for film radiographic testing of castings. Films after exposure and processing become radiographs with different area of optical density. Radiographs are viewed and evaluated using industrial radiographic illuminators. This part of EN 12681 specifies the recommended procedure for the choice of operating conditions and radiographic practice. These procedures are applicable to castings produced by any casting process, especially for steel, cast iron, aluminium, cobalt, copper, magnesium, nickel, titanium, zinc and any alloys of them. NOTE This European Standard considers EN ISO 5579. This part of this European Standard does not apply to: — radiographic testing of castings for aerospace applications (see prEN 2002-21); — radiographic testing of welded joints (see EN ISO 17636-1); — radiography with digital detectors (see EN 12681-2); — radioscopic testing (see EN 13068, all parts). 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 12543, Non-destructive testing — Characteristics of focal spots in industrial X-ray systems for use in non-destructive testing (all parts) EN 12679, Non-destructive testing - Determination of the size of industrial radiographic sources - Radiographic method EN 25580, Non-destructive testing - Industrial radiographic illuminators - Minimum requirements (ISO 5580:1985) EN ISO 5579:2013, Non-destructive testing - Radiographic testing of metallic materials using film and X- or gamma rays - Basic rules (ISO 5579:2013) EN ISO 9712, Non-destructive testing - Qualification and certification of NDT personnel (ISO 9712) EN ISO 11699-1, Non-destructive testing - Industrial radiographic film - Part 1: Classification of film systems for industrial radiography (ISO 11699-1) EN ISO 11699-2, Non-destructive testing - Industrial radiographic films - Part 2: Control of film processing by means of reference values (ISO 11699-2) EN ISO 19232-1, Non-destructive testing - Image quality of radiographs - Part 1: Determination of the image quality value using wire-type image quality indicators (ISO 19232-1) SIST EN 12681-1:2018
EN 12681-1:2017 (E) 7 EN ISO 19232-2, Non-destructive testing - Image quality of radiographs - Part 2: Determination of the image quality value using step/hole-type image quality indicators (ISO 19232-2) ISO 5576, Non-destructive testing — Industrial X-ray and gamma-ray radiology — Vocabulary ASTM E 1320:2010, Reference Radiographs for Titanium Castings 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 5576, EN ISO 5579 and the following apply. 3.1 wall thickness t thickness as measured on the casting 3.2 nominal wall thickness tn thickness as specified on the drawing 3.3 penetrated thickness w thickness of material in the direction of the radiation beam calculated on the basis of the real thicknesses of all penetrated walls 3.4 source size d size of the radiation source or focal spot size [SOURCE: EN ISO 5579:2013, definition 3.4] 3.5 object-to-film distance b largest (maximum) distance between the source side of the radiographed part of the test object and the film surface measured along the central axis of the radiation beam 3.6 source-to-object distance f distance between the source of radiation and the source side of the test object, most distant from the film, measured along the central axis of the radiation beam SIST EN 12681-1:2018
EN 12681-1:2017 (E) 8 3.7 source-to-film distance SFD distance between the source of radiation and the film measured in the direction of the beam Note 1 to entry: SFD = f + b where f source-to-object distance; b object-to-film distance. [SOURCE: EN ISO 5579:2013, definition 3.5, modified – description in words presented as formula] 4 Symbols and abbreviations For the purposes of this document, the symbols and abbreviations given in Table 1 apply. Table 1 — Symbols and abbreviations Symbol or abbreviation Term Clause, Figure, Annex b object-to-film distance 3.5 d source size 3.4 D optical density of film Clause 12 14.2 Figure 16 Figure 15 f source-to-object distance 3.6 F Film Figure 1 IQI image quality indicator Clause 16 Annex A S source of radiation Figure 1 SFD source-to film-distance 3.7 t wall thickness 3.1 Figure 1 tn nominal wall thickness 3.2 Annexes B to F w penetrated thickness 3.3 SIST EN 12681-1:2018
EN 12681-1:2017 (E) 9 5 Classification of radiographic techniques The radiographic techniques are divided into two classes: — Class A: basic techniques; — Class B: improved techniques. It is recommended to perform the testing according to class A, if not otherwise specified in the order. Class B techniques will be used when class A might be insufficiently sensitive. If, for technical or industrial reasons, it is not possible to meet one of the conditions specified for class B, such as the type of radiation source or the source-to-object distance f, it may be agreed by contracting parties that the condition selected may be what is specified for class A. In film radiography the loss of sensitivity shall be compensated by an increase of minimum optical density to 3,0 or by selection of a two class better film system. The other conditions for class B remain unchanged, especially the image quality achieved. Because of the better sensitivity compared to class A, the test specimen may be regarded as being examined to class B. This does not apply if the special SFD reductions as specified in Clause 11 for test arrangements Figure 3 and Figure 4 are used. 6 General preparations and requirements 6.1 General preparations 6.1.1 Protection against ionizing radiation Local, national or international safety precautions shall be strictly applied, when using ionizing radiation. WARNING — Exposure of any part of the human body to X-rays or gamma-rays can be highly injurious to health. Wherever X-ray equipment or radioactive sources are in use, appropriate legal requirements shall be applied. 6.1.2 Surface preparation and stage of manufacture In general, surface preparation is not necessary, but where surface imperfections can cause difficulty in detecting discontinuities, the surface shall be ground smooth. Unless otherwise specified radiography shall be carried out after the final stage of manufacture, e.g. after grinding or heat treatment. NOTE For some aluminium and magnesium alloy castings, radiography can be carried out before heat treatment. 6.2 Agreements Castings with a complex geometry can include areas which cannot be tested by radiography or can only be partly tested. Such areas shall be identified before starting the radiographic testing. Areas which cannot be tested by radiography shall be noted by all contracting parties and be marked on the film position plan. The following items shall be agreed between the contracting parties by the time of acceptance of the order: a) manufacturing stage at which castings are to be tested; b) extent of radiographic testing; SIST EN 12681-1:2018
EN 12681-1:2017 (E) 10 c) test areas; d) surface condition; e) testing class; f) information about the film position plan; g) marking of test areas on the casting; h) image quality; i) marking of the radiographs; j) acceptance criteria; k) any additional items; l) any special requirements. 6.3 Personnel qualification Unless otherwise agreed, testing shall be performed by personnel qualified in accordance with EN ISO 9712 or equivalent to an appropriate level in the relevant industrial sector. 7 Test arrangements 7.1 General The test arrangements to be used shall be in accordance with: — Figures 1 to 4: for single wall radiography; — Figures 5 to 7: for double wall radiography; — Figures 8 to 12: for test areas of complex section. NOTE For an explanation of the symbols in the figures, see Table 1. If these arrangements are not applicable, other arrangements may be used. 7.2 Single wall radiography of plane areas The test arrangement for single wall radiography of plane areas shall be in accordance with Figure 1. 7.3 Single wall radiography of curved areas The test arrangement for single wall radiography of curved areas shall be in accordance with either Figures 2, 3 or 4. NOTE Rigid cassettes can be used if the corresponding increase of b is considered for the calculation of the distance f between the source and source side of the test object (see Clause 11). 7.4 Double wall radiography of plane and curved areas The test arrangement for double wall radiography of plane and curved areas shall be in accordance with either Figures 5, 6 or 7. SIST EN 12681-1:2018
EN 12681-1:2017 (E) 11 In the case of test arrangements according to Figure 5, the distance of the source from the surface of the test area shall be minimized provided that the requirements of IQI are met. In the case of test arrangements according to Figures 6 and 7, the discontinuities shall be classified with reference to the single wall thickness. In the case of different wall thicknesses the reference shall be the smaller one. Double wall radiography shall be used, as an overview technique according to Figure 7, if the geometrical conditions make other test arrangements difficult to apply or if there is a better sensitivity for detecting discontinuities by using this technique. It shall be ensured that unacceptable discontinuities are detected with sufficient certainty. The required image quality shall be met. 7.5 Choice of test arrangements for complex geometries Unless otherwise agreed, the test arrangements for complex geometry areas shall be in accordance with Figures 8 to 12 (as appropriate). 7.6 Acceptable test area dimensions The test area to be captured with one radiographic film should be limited in a way that the required optical density according to Clause 12, Table 5 is met in the region of interest. In addition to the requirements above, the angle of incident radiation in the entire region of interest shall not exceed 30 °. NOTE This value can be larger, if special orientations of discontinuities can be detected in this way or if it is the only way to test areas otherwise impossible to test.
Figure 1 — Test arrangement for single wall radiography of plane areas SIST EN 12681-1:2018
EN 12681-1:2017 (E) 12
a) with flexible cassette b) with rigid cassette Figure 2 — Test arrangement for single wall radiography of curved areas with the source on the convex side and the film on the concave side of the test area
a) with flexible cassette b) with rigid cassette Figure 3 — Test arrangement for single wall radiography of curved areas with eccentric positioning of the source on the concave side and the film on the convex side of the test area
Figure 4 — Test arrangement for single wall radiography of curved areas with central positioning of the source on the concave side and film on the convex side of the test area SIST EN 12681-1:2018
EN 12681-1:2017 (E) 13
Figure 5 — Test arrangement for double wall radiography of plane or curved test areas; source and film outside the test area, only the film side wall imaged for interpretation
Figure 6 — Test arrangement for double wall radiography of plane or curved test areas; several exposures; source and film outside of the test area; both walls imaged for interpretation
Figure 7 — Test arrangement for double wall radiography of plane or curved test areas; overview exposure; source and film outside of the test area; both walls imaged for interpretation SIST EN 12681-1:2018
EN 12681-1:2017 (E) 14
a) b) should only be used, if a) is not possible. Figure 8 — Examples for edges and flanges
a)
b) should only be used, if a) is not possible. Figure 9 — Examples for ribs SIST EN 12681-1:2018
EN 12681-1:2017 (E) 15
Figure 10 — Example for cross like geometries
Figure 11 — Example for wedge geometries SIST EN 12681-1:2018
EN 12681-1:2017 (E) 16
a)
b) Figure 12 — Example for ribs and supports 8 Choice of tube voltage and radiation source 8.1 X-ray devices up to 1 000 kV To maintain good detection sensitivity, the X-ray tube voltage should be as low as possible. The maximum values of X-ray tube voltage versus thickness are given in Figure 13. SIST EN 12681-1:2018
EN 12681-1:2017 (E) 17
Key 1 copper/nickel and alloys 2 steel and cast irons 3 titanium and alloys 4 aluminium and alloys w penetrated thickness in mm U X-ray voltage in kV Figure 13 — Maximum X-ray voltage U for X-ray devices up to 1 000 kV as a function of penetrated thickness w and material For some casting applications where the thickness changes across the area of test object being radiographed, a modification of technique with a higher voltage may be used, but it should be noted that an excessively high tube voltage will lead to a loss of detection sensitivity. If there are different thicknesses imaged with one exposure, an averaged value of these thicknesses can be used. 8.2 Other radiation sources The penetrated thickness ranges for gamma ray sources and X-ray equipment above 1 MeV are given in Table 2 for steels, cast irons, cobalt, copper and nickel based alloys. For aluminium, magnesium, titanium and zinc testing using Se 75, the penetrated material thickness is 35 mm
¶ w
¶ 120 mm for class A. Gamma rays from Se 75, Ir 192 and Co 60 sources will not produce radiographs having as good detection sensitivity as X-rays used with appropriate technique parameters. However because of the advantages of gamma ray sources in handling and accessibility, Table 2 gives a range of thicknesses for which each of these gamma ray sources may be used when the use of X-ray tubes is difficult. By agreement between the contracting parties, the penetrated material thickness for Ir 192 may be further reduced to 10 mm and reduced to 5 mm for Se 75. For certain applications wider material thickness ranges may be permitted, if sufficient image quality can be achieved. SIST EN 12681-1:2018
EN 12681-1:2017 (E) 18 For gamma rays, the total travel-time to and from the source position shall not exceed 10 % of the total exposure time. Table 2 — Penetrated thickness range for gamma ray sources and X-ray equipment with energy above 1 MeV for steels, cast irons, cobalt, copper and nickel base alloys Radiation source Penetrated thickness wa mm Class A Class B Se 75 10
¶ w
¶ 40 14
¶ w
¶ 40 Ir 192 10
¶ w
¶ 100 20
¶ w
¶ 90 Co 60 40
¶ w
¶ 200 60
¶ w
¶ 150 X-ray equipment with energy from 1 MeV to 4 MeV 30
¶ w
¶ 300 50
¶ w
¶ 180 X-ray equipment with energy from 4 MeV to 12 MeV w
· 50b w
· 70b X-ray equipment with energy above 12 MeV w
· 80b w
· 100b a If there are different thicknesses imaged with one exposure, an averaged value of these thicknesses can be used. b The minimum penetrated wall thickness may be reduced by 10 mm in class A and by 20 mm in class B, if film system class C1 according to EN ISO 11699-1 is used, provided the IQI requirements are met. 9 Film systems and metal screens For radiographic testing film system classes shall be used in accordance with EN ISO 11699-1. For different radiation sources the minimum film system classes are given in Tables 3 and 4. When using metal screens good contact between films and screens are required. This may be achieved either by using vacuum-packed films or by applying pressure. Other screen thicknesses may be also agreed between the contracting parties provided the required image quality is achieved. SIST EN 12681-1:2018
EN 12681-1:2017 (E) 19 Table 3 — Film system classes and metal screens for the radiography of steels, cast irons, cobalt, copper and nickel base alloys Radiation source Penetrated thickness w Film system classa Type and thickness of metal screens Class A Class B Class A Class B X-ray potentials
¶ 100 kV all w C 5 C 3 none or up to 0,03 mm front and back screens of lead X-ray potentials > 100 kV to 150 kV up to 0,15 mm front and back screens of lead X-ray potentials > 150 kV to 250 kV C 4 0,02 mm to 0,15 mm front and back screens of lead X-ray potentials > 250 kV to 500 kV w
¶ 50 mm C 5 C 4 0,02 mm to 0,2 mm front and back screens of lead w > 50 mm C 5 0,1 mm to 0,2 mm front screens of leadb 0,02 mm to 0,2 mm back screens of lead X-ray potentials > 500 kV to 1000 kV w
¶ 75 mm C 5 C 4 0,25 mm to 0,7 mm front and back screens of steel or copperc w > 75 mm C 5 C 5 Se 75 all w C 5 C 4 0,02 mm to 0,2 m
...
SLOVENSKI STANDARD
oSIST prEN 12681-1:2016
01-maj-2016
Livarstvo - Radiografsko preskušanje - 1. del: Filmske tehnike
Founding - Radiographic testing - Part 1: Film techniques
Gießereiwesen - Durchstrahlungsprüfung - Teil 1: Filmtechniken
Fonderie - Contrôle par radiographie - Partie 1 : Techniques à l'aide de films
Ta slovenski standard je istoveten z: prEN 12681-1
ICS:
77.040.20 Neporušitveno preskušanje Non-destructive testing of
kovin metals
oSIST prEN 12681-1:2016 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN 12681-1:2016
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oSIST prEN 12681-1:2016
DRAFT
EUROPEAN STANDARD
prEN 12681-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2016
ICS 77.040.20 Will supersede EN 12681:2003
English Version
Founding - Radiographic testing - Part 1: Film techniques
Fonderie - Contrôle par radiographie - Partie 1 : Gießereiwesen - Durchstrahlungsprüfung - Teil 1:
Techniques à l'aide de films Filmtechniken
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 190.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2016 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 12681-1:2016 E
worldwide for CEN national Members.
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Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Symbols and abbreviations . 8
5 Classification of radiographic techniques . 9
6 Requirements . 9
6.1 General preparations . 9
6.1.1 Protection against ionizing radiation . 9
6.1.2 Surface preparation and stage of manufacture . 9
6.2 Agreements . 9
6.3 Personnel qualification . 10
7 Test arrangements . 10
7.1 General . 10
7.2 Single wall radiography of plane areas . 10
7.3 Single wall radiography of curved areas . 10
7.4 Double wall radiography of plane and curved areas . 10
7.5 Choice of test arrangements for complex geometries . 11
7.6 Acceptable test area dimensions . 11
8 Choice of tube voltage and radiation source . 16
8.1 X-ray devices up to 1 000 kV . 16
8.2 Other radiation sources . 17
9 Film systems and metal screens . 17
10 Reduction of scattered radiation . 19
10.1 Metal filters and collimators . 19
10.2 Interception of backscattered radiation. 19
11 Source-to-object distance . 20
12 Optical density D of radiograph . 22
13 Film processing and viewing . 22
13.1 Processing . 22
13.2 Film viewing conditions . 22
14 Techniques for increasing the covered thickness range . 23
14.1 General . 23
14.2 Multiple film technique . 23
14.3 Contrast decreasing by higher radiation energy . 24
14.4 Contrast decreasing by beam hardening . 24
14.5 Contrast decreasing by thickness equalization. 25
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15 Radiographs . 25
15.1 Identification of radiograph, test area, film position plan. 25
15.2 Marking of the test areas . 25
15.3 Overlap of films . 25
16 Verification of image quality . 25
17 Influence of crystalline structure . 26
18 Acceptance criteria . 26
18.1 General . 26
18.2 Severity levels . 26
18.3 Wall section zones . 26
19 Test report . 27
Annex A (normative) Minimum image quality values . 29
Annex B (normative) Severity levels for steel castings . 32
Annex C (normative) Severity levels for iron castings . 35
Annex D (normative) Severity levels for aluminium alloy and magnesium alloy castings . 38
Annex E (normative) Severity levels for copper alloy castings . 42
Annex F (normative) Severity levels for titanium and titanium alloy castings . 44
Annex G (informative) Significant technical changes between this European Standard and
the previous edition . 46
Bibliography . 47
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European foreword
This document (prEN 12681-1:2016) has been prepared by Technical Committee CEN/TC 190
“Foundry Technology”, the secretariat of which is held by DIN.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 12681:2003.
Within its programme of work, Technical Committee CEN/TC 190 requested CEN/TC 190/WG 10
“Inner defects” to revise and to split the following standard:
EN 12681:2003, Founding — Radiographic testing
into:
— prEN 12681-1, Founding — Radiographic testing — Part 1: Film techniques
(replacement for EN 12681:2003)
— prEN 12681-2, Founding — Radiographic testing — Part 2: Techniques with digital detectors
(new issue and part of EN 12681:2003)
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Introduction
Radiography can be used to detect internal discontinuities in a casting. The discontinuities can be gas
holes, non-metallic inclusions, shrinkage, cracks, inserts or chills or inclusions that have lower or higher
densities than the parent metal. This European Standard gives acceptance criteria through severity
levels.
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1 Scope
This European Standard gives specific procedures for industrial X-ray and gamma radiography for
discontinuity detection purposes, using NDT (Non-destructive testing) film techniques. This part of
EN 12681 specifies the requirements for film radiographic testing of castings.
Films after exposure and processing become radiographs with different area of optical density.
Radiographs are viewed and evaluated using industrial radiographic illuminators.
This part of EN 12681 specifies the recommended procedure for the choice of operating condition
selection and radiographic practice.
These procedures are applicable to castings produced by any casting process, especially for steel, cast
iron, aluminium, cobalt, copper, magnesium, nickel, titanium, zinc and any alloys of them.
NOTE This European Standard complies with EN ISO 5579.
This part of this European Standard does not apply to:
— radiographic testing of castings for aerospace applications (see prEN 2002-21);
— radiographic testing of welded joints (see EN ISO 17636-1);
— radiography with digital detectors (see prEN 12681-2);
— radioscopic testing (see EN 13068, all parts).
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
EN 12543, Non-destructive testing — Characteristics of focal spots in industrial X-ray systems for use in
non-destructive testing (all parts)
EN 12679, Non-destructive testing - Determination of the size of industrial radiographic sources -
Radiographic method
EN 25580, Non-destructive testing - Industrial radiographic illuminators - Minimum requirements (ISO
5580:1985)
EN ISO 5579:2013, Non-destructive testing - Radiographic testing of metallic materials using film and X-
or gamma rays - Basic rules (ISO 5579:2013)
EN ISO 9712, Non-destructive testing - Qualification and certification of NDT personnel (ISO 9712)
EN ISO 11699-1, Non-destructive testing - Industrial radiographic film - Part 1: Classification of film
systems for industrial radiography (ISO 11699-1)
EN ISO 11699-2, Non-destructive testing - Industrial radiographic films - Part 2: Control of film processing
by means of reference values (ISO 11699-2)
EN ISO 19232-1, Non-destructive testing - Image quality of radiographs - Part 1: Determination of the
image quality value using wire-type image quality indicators (ISO 19232-1)
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EN ISO 19232-2, Non-destructive testing - Image quality of radiographs - Part 2: Determination of the
image quality value using step/hole-type image quality indicators (ISO 19232-2)
EN ISO 19232-4, Non-destructive testing - Image quality of radiographs - Part 4: Experimental evaluation
of image quality values and image quality tables (ISO 19232-4)
ISO 5576, Non-destructive testing — Industrial X-ray and gamma-ray radiology — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 5576, EN ISO 5579 and the
following apply.
3.1
wall thickness
t
thickness as measured on the casting
3.2
nominal wall thickness
t
n
thickness as specified on the drawing
3.3
penetrated thickness
w
thickness of material in the direction of the radiation beam calculated on the basis of the real
thicknesses of all penetrated walls
3.4
source size
d
size of the radiation source or focal spot size
[SOURCE: EN ISO 5579:2013, definition 3.4]
3.5
object-to-film distance
b
largest (maximum) distance between the source side of the radiographed part of the test object and the
film surface measured along the central axis of the radiation beam
3.6
source-to-object distance
f
distance between the source of radiation and the source side of the test object, most distant from the
film, measured along the central axis of the radiation beam
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3.7
source-to-film distance
SFD
distance between the source of radiation and the film measured in the direction of the beam
Note 1 to entry: SFD = f + b
where
f source-to-object distance;
b object-to-film distance.
[SOURCE: EN ISO 5579:2013, definition 3.5, modified – description in words presented as formula]
4 Symbols and abbreviations
For the purposes of this document, the symbols and abbreviations given in Table 1 apply.
Table 1 — Symbols and abbreviations
symbol or Clause,
Term
abbreviation Figure, Annex
b object-to-film distance 3.5
d source size 3.4
Clause 12
14.2
D optical density of film
Clause 16
Figure 15
f source-to-object distance 3.6
F Film Figure 1
Clause 16
IQI image quality indicator
Annex A
S source of radiation Figure 1
SFD source-to film-distance 3.7
3.1
t wall thickness
Figure 1
3.2
t
nominal wall thickness
n
Annexes B to F
w penetrated thickness 3.3
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5 Classification of radiographic techniques
The radiographic techniques are divided into two classes:
— Class A: basic techniques;
— Class B: improved techniques.
It is recommended to perform the testing according to class A, if not otherwise specified in the order.
Class B techniques will be used when class A might be insufficiently sensitive.
If, for technical or industrial reasons, it is not possible to meet one of the conditions specified for class B,
such as the type of radiation source or the source-to-object distance f, it may be agreed by contracting
parties that the condition selected may be what is specified for class A. In film radiography the loss of
sensitivity shall be compensated by an increase of minimum optical density to 3,0 or by selection of a
two class better film system. The other conditions for class B remain unchanged, especially the image
quality achieved. Because of the better sensitivity compared to class A, the test specimen may be
regarded as being examined to class B. This does not apply if the special SFD reductions as specified in
Clause 11 for test arrangements Figure 3 and Figure 4 are used.
6 Requirements
6.1 General preparations
6.1.1 Protection against ionizing radiation
Local, national or international safety precautions shall be strictly applied, when using ionizing
radiation.
WARNING — Exposure of any part of the human body to X-rays or gamma-rays can be highly injurious
to health. Wherever X-ray equipment or radioactive sources are in use, appropriate legal requirements
shall be applied.
6.1.2 Surface preparation and stage of manufacture
In general, surface preparation is not necessary, but where surface imperfections can cause difficulty in
detecting defects, the surface shall be ground smooth.
Unless otherwise specified radiography shall be carried out after the final stage of manufacture, e.g.
after grinding or heat treatment.
6.2 Agreements
Castings with a complex geometry can include areas which cannot be tested by radiography or can only
be partly tested. Such areas shall be identified before starting the radiographic testing. Areas which
cannot be tested by radiography shall be noted by all contracting parties and be marked on the film
position plan.
The following items shall be agreed:
a) manufacturing stage at which castings are to be tested;
b) extent of radiographic testing;
c) test areas;
d) surface condition;
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e) testing class;
f) information about the film position plan;
g) marking of test areas on the casting;
h) image quality;
i) marking of the radiographs;
j) acceptance criteria;
k) any additional items shall be agreed between the contracting parties;
l) any special requirements.
All requirements shall be agreed between the contracting parties by the time of acceptance of the order.
6.3 Personnel qualification
Unless otherwise agreed, testing shall be performed by personnel qualified in accordance with
EN ISO 9712 or equivalent to an appropriate level in the relevant industrial sector.
7 Test arrangements
7.1 General
The test arrangements to be used shall be in accordance with:
— Figures 1 to 4: for single wall radiography;
— Figures 5 to 7: for double wall radiography;
— Figures 8 to 12: for test areas of complex section.
If these arrangements are not applicable, other arrangements may be used.
7.2 Single wall radiography of plane areas
The test arrangement for single wall radiography of plane areas shall be in accordance with Figure 1.
7.3 Single wall radiography of curved areas
The test arrangement for single wall radiography of curved areas shall be in accordance with either
Figures 2, 3 or 4.
NOTE Rigid cassettes can be used if the corresponding increase of b is considered for the calculation of the
distance f between the source and source side of the test object (see Clause 10).
7.4 Double wall radiography of plane and curved areas
The test arrangement for double wall radiography of plane and curved areas shall be in accordance with
either Figures 5, 6 or 7.
Double wall radiography shall be used, as an overview technique according to Figure 7, if the
geometrical conditions make other test arrangements difficult to apply or if there is a better sensitivity
for detecting discontinuities by using this technique. It shall be ensured that unacceptable
discontinuities are detected with sufficient certainty. The required image quality shall be met.
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In the case of test arrangements according to Figures 6 and 7, the discontinuities shall be classified with
reference to the single wall thickness. In the case of different wall thicknesses the reference shall be the
smaller one.
In the case of test arrangements according to Figure 5, the distance of the source from the surface of the
test area shall be minimized provided that the requirements of IQI are met.
7.5 Choice of test arrangements for complex geometries
Unless otherwise agreed, the test arrangements for complex geometry areas shall be in accordance with
Figures 8 to 12 (as appropriate).
7.6 Acceptable test area dimensions
The test area to be captured with one radiographic film should be limited in a way that the required
optical density according to Clause 12, Table 5 is met in the region of interest.
In addition to the requirements above, the angle of incident radiation in the entire region of interest
shall not exceed 30°.
NOTE This value can be larger, if special orientations of discontinuities can be detected in this way or if it is
the only way to test areas otherwise impossible to test.
Figure 1 — Test arrangement for single wall radiography of plane areas
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a) with flexible cassette b) with rigid cassette
Figure 2 — Test arrangement for single wall radiography of curved areas with the source on the
convex side and the film on the concave side of the test area
a) with flexible cassette b) with rigid cassette
Figure 3 — Test arrangement for single wall radiography of curved areas with eccentric
positioning of the source on the concave side and the film on the convex side of the test area
Figure 4 — Test arrangement for single wall radiography of curved areas with central
positioning of the source on the concave side and film on the convex side of the test area
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Figure 5 —Test arrangement for double wall radiography of plane or curved test areas; source
and film outside the test area, only the film side wall imaged for interpretation
Figure 6 — Test arrangement for double wall radiography of plane or curved test areas; several
exposures; source and film outside of the test area; both walls imaged for interpretation
Figure 7 — Test arrangement for double wall radiography of plane or curved test areas;
overview exposure; source and film outside of the test area; both walls imaged for
interpretation
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a) b) should only be used, if a) is not possible.
Figure 8 — Examples for edges and flanges
a)
b) should only be used, if a) is not possible.
Figure 9 — Examples for ribs
Figure 10 — Example for cross like geometries
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Figure 11 — Example for wedge geometries
a)
b)
Figure 12 — Example for ribs and supports
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8 Choice of tube voltage and radiation source
8.1 X-ray devices up to 1 000 kV
To maintain good flaw sensitivity, the X-ray tube voltage should be as low as possible. The maximum
values of X-ray tube voltage versus thickness are given in Figure 13.
Key
1 copper/nickel and alloys
2 steel and cast irons
3 titanium and alloys
4 aluminium and alloys
w penetrated thickness in mm
U X-ray voltage in kV
Figure 13 — Maximum X-ray voltage U for X-ray devices up to 1 000 kV as a function of
penetrated thickness w and material
For some casting applications where the thickness changes across the area of test object being
radiographed, a modification of technique with a higher voltage may be used, but it should be noted that
an excessively high tube voltage will lead to a loss of defect detection sensitivity. If there are different
thicknesses imaged with one exposure, an averaged value of these thicknesses can be used.
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8.2 Other radiation sources
The recommended penetrated thickness ranges for gamma ray sources and X-ray equipment above
1 MeV are given in Table 2 for steel, cobalt, copper and nickel based alloys.
For aluminium, magnesium, titanium and zinc testing using Se 75, the penetrated material thickness is
35 mm ≤ w ≤ 120 mm for class A.
Gamma rays from Se 75, Ir 192 and Co 60 sources will not produce radiographs having as good defect
detection sensitivity as X-rays used with appropriate technique parameters. However because of the
advantages of gamma ray sources in handling and accessibility, Table 2 gives a range of thicknesses for
which each of these gamma ray sources may be used when the use of X-ray tubes is difficult.
By agreement between the contracting parties, the penetrated material thickness for Ir 192 may be
further reduced to 10 mm and reduced to 5 mm for Se 75.
For certain applications wider material thickness ranges may be permitted, if sufficient image quality
can be achieved.
For gamma rays, the total travel-time to and from the source position shall not exceed 10 % of the total
exposure time.
Table 2 — Penetrated thickness range for gamma ray sources and X-ray equipment
with energy above 1 MeV for steel, cast irons, cobalt, copper and nickel base alloys
Radiation source Penetrated thickness
a
w
mm
Class A Class B
Se 75 10 ≤ w ≤ 40 14 ≤ w ≤ 40
Ir 192 10 ≤ w ≤ 100 20 ≤ w ≤ 90
Co 60 40 ≤ w ≤ 200 60 ≤ w ≤ 150
X-ray equipment with energy
30 ≤ w ≤ 300 50 ≤ w ≤ 180
from 1 MeV to 4 MeV
X-ray equipment with energy
b b
w ≥ 50 w ≥ 70
from 4 MeV to 12 MeV
X-ray equipment with energy
b b
w ≥ 80 w ≥ 100
above 12 MeV
a
If there are different thicknesses imaged with one exposure, an averaged value of these thicknesses can be used.
b
The minimum penetrated wall thickness may be reduced by 10 mm in class A and by 20 mm in class B, if film system
class C1 according to EN ISO 11699-1 is used, provided the IQI requirements are met.
9 Film systems and metal screens
For radiographic testing film system classes shall be used in accordance with EN ISO 11699-1.
For different radiation sources the minimum film system classes are given in Tables 3 and 4.
When using metal screens good contact between films and screens are required. This may be achieved
either by using vacuum-packed films or by applying pressure.
Other screen t
...
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