EN 12680-1_2003

BRITISH STANDARD BS EN 12680-1:2003 Founding — Ultrasonic examination — Part 1: Steel castings for general purposes The European Standard EN 12680-1:2003 has the status of a British Standard BS EN 12680-1:2003 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 5 February 2003 National foreword This British Standard is the official English language version of EN 12680-1:2003. It supersedes BS 6208:1990 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee ISE/NFE/9, Foundry technology, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. — aid enquirers to understand the text; — present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; — monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 33 and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date Comments --`,,,,`,,````,,,`,,,`,`,,,``,`-`-`,,`,,`,`,,`--- EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN 12680-1 January 2003 ICS 77.040.20 English version Founding - Ultrasonic examination - Part 1: Steel castings for general purposes Fonderie - Contrôle par ultrasons - Partie 1: Pièces moulées en acier pour usages généraux Gießereiwesen - Ultraschallprüfung - Teil 1: Stahlgussstücke für allgemeine Verwendung This European Standard was approved by CEN on 21 November 2002. 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. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Management Centre or to any CEN member. This European Standard exists 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 Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION C O M I T É E U R O P É E N D E N O R M A LI S A T I O N EUR OP ÄIS C HES KOM ITEE FÜR NOR M UNG Management Centre: rue de Stassart, 36 B-1050 Brussels Ref. No. EN 12680-1:2003 E EN 12680-1:2003 (E) 2 Contents page Foreword......................................................................................................................................................................3 1 Scope ..............................................................................................................................................................4 2 Normative references ....................................................................................................................................4 3 Terms and definitions....................................................................................................................................4 4 Requirements .................................................................................................................................................5 4.1 Order information ..........................................................................................................................................5 4.2 Extent of examination....................................................................................................................................6 4.3 Maximum permissible size of discontinuities.............................................................................................6 4.4 Personnel qualification .................................................................................................................................6 4.5 Wall section zones.........................................................................................................................................7 4.6 Severity levels ................................................................................................................................................7 5 Examination....................................................................................................................................................7 5.1 Principles ........................................................................................................................................................7 5.2 Material............................................................................................................................................................7 5.3 Equipment and coupling medium ................................................................................................................8 5.4 Preparation of casting surfaces for examination .......................................................................................8 5.5 Examination procedure .................................................................................................................................9 5.6 Examination report ......................................................................................................................................11 Annex A (informative) Sound-beam diameters .....................................................................................................19 Annex B (informative) Types of indications ..........................................................................................................21 Bibliography ..............................................................................................................................................................33 EN 12680-1:2003 (E) 3 Foreword This document (EN 12680-1:2003) has been prepared by Technical Committee CEN/TC 190 "Foundry Technol- ogy", 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 July 2003, and conflicting national standards shall be withdrawn at the latest by July 2003. Within its programme of work, Technical Committee CEN/TC 190 requested CEN/TC 190/WG 4.10 "Inner defects" to prepare the following standard: EN 12680-1, Founding — Ultrasonic examination — Part 1: Steel castings for general purposes. This is one of three European Standards for ultrasonic examination. The other standards are: EN 12680-2, Founding — Ultrasonic examination — Part 2: Steel castings for highly stressed components. EN 12680-3, Founding — Ultrasonic examination — Part 3: Spheroidal graphite cast iron castings. Annexes A and B are informative. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following coun- tries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Swe- den, Switzerland and the United Kingdom. EN 12680-1:2003 (E) 4 1 Scope This European Standard specifies the requirements for the ultrasonic examination of steel castings (with ferritic structure) for general purposes and the methods for determining internal discontinuities by the pulse-echo tech- nique. This European Standard applies to the ultrasonic examination of steel castings which have usually received a grain refining heat treatment and which have wall thicknesses up to and including 600 mm. For greater wall thicknesses, special agreements apply with respect to test procedure and recording levels. This European Standard does not apply to austenitic steels and joint welds. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text, and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies (including amendments). EN 583-1, Non-destructive testing — Ultrasonic examination — Part 1: General principles. EN 583-2, Non-destructive testing — Ultrasonic examination — Part 2: Sensitivity and range setting. EN 583-5, Non-destructive testing — Ultrasonic examination — Part 5: Characterization and sizing of discon- tinuities. EN 12223, Non-destructive testing — Ultrasonic examination — Specification for calibration block No. 1. EN 12668-1, Non-destructive testing — Characterization and verification of ultrasonic examination equipment — Part 1: Instruments. EN 12668-2, Non-destructive testing — Characterization and verification of ultrasonic examination equipment — Part 2: Probes. EN 12668-3, Non-destructive testing — Characterization and verification of ultrasonic examination equipment — Part 3: Combined equipment. EN 27963, Welds in steel — Calibration block No. 2 for ultrasonic examination of welds (ISO 7963:1985). 3 Terms and definitions For the purposes of this European Standard, the following terms and definitions apply. NOTE Other terms and definitions used in this European Standard are given in EN 583-1, EN 583-2, EN 583-5 and EN 1330-4. 3.1 reference discontinuity echo size smallest indication to be recorded during the assessment phase of an ultrasonic examination, usually expressed as an equivalent flat-bottomed hole diameter EN 12680-1:2003 (E) 5 3.2 point discontinuity discontinuity, the dimensions of which are smaller than or equal to the sound-beam width NOTE Dimensions in this standard relate to length, width and/or dimension in through-wall direction. 3.3 complex discontinuity discontinuity, the dimensions of which are larger than the sound-beam width NOTE Dimensions in this standard relate to length, width and/or dimension in through-wall direction. 3.4 planar discontinuity discontinuity having two measurable dimensions 3.5 volumetric discontinuity discontinuity having three measurable dimensions 3.6 special rim zone outer rim zone part with special requirements (for e.g. machined surfaces, higher stresses, sealing surfaces) 3.7 production welding any welding carried out during manufacturing before final delivery to the purchaser 3.7.1 joint welding production welding used to assemble components together to obtain an integral unit 3.7.2 finishing welding production welding carried out in order to ensure the agreed quality of the casting 4 Requirements 4.1 Order information The following information shall be available at the time of enquiry and order (see also EN 583-1): ¾ the areas of the casting and the number or percentage of castings to which the ultrasonic examination require- ments apply (examination volume, extent of examination); ¾ the severity level to be applied to the various zones or areas of the casting (acceptance criteria); ¾ requirements for a written examination procedure; ¾ whether there are any additional requirements for the examination procedure, see also 5.5.1. EN 12680-1:2003 (E) 6 4.2 Extent of examination The casting shall be examined so that the agreed areas are totally covered (insofar as this is possible from the shape of the casting) by the use of the best applicable examination technique. For wall thicknesses greater than 600 mm, agreement shall be made between the parties concerned on the exami- nation procedure and also on the recording and acceptance levels. 4.3 Maximum permissible size of discontinuities 4.3.1 Limits of acceptance for planar discontinuities mainly orientated perpendicular to the surface The limits of acceptance for planar discontinuities are given in Figure 1. Indications with measurable dimensions are not permissible as severity level 1. The largest dimension in through-wall direction shall not exceed 10 % of wall thickness, except indications with a measurable length £ 10 mm. Such indications shall not exceed a dimension in through-wall direction of 25 % of wall thickness or 20 mm. The greatest distance between indications as criterion for evaluation as single indication or indication area perpen- dicular or lateral to the surface shall be 10 mm. For an area with measurable length and non-measurable dimension in through-wall direction, this non-measurable dimension shall be taken as 3 mm and the area be calculated: A = 3 · L (1) where ¾ A is the area of indication expressed in square millimetres; ¾ 3 is the taken width in millimetres; ¾ L is the measurable length expressed in millimetres. 4.3.2 Limits of acceptance for volumetric discontinuities The limits of acceptance for volumetric discontinuities are given in Table 1. Any discontinuity exceeding one of the criteria shall be considered as unacceptable. 4.3.3 Maximum permissible discontinuities in the case of radiographic examination of the casting carried out as a supplement to ultrasonic examination Unless otherwise agreed by the time of enquiry and order, when, after conducting the radiographic and the ultra- sonic examination in combination, it has been demonstrated that a discontinuity is situated in the core zone, this additional information makes the discontinuity acceptable at one level less severe, e.g. severity level 3 instead of 2 for radiographic examination, see EN 1559-2. 4.4 Personnel qualification It is assumed that ultrasonic examination is performed by qualified and capable personnel. In order to prove this qualification, it is recommended to certify personnel in accordance with EN 473. EN 12680-1:2003 (E) 7 4.5 Wall section zones The wall section shall be divided into zones as shown in Figure 2. These sections relate to the dimensions of the casting ready for assembly (finish machined). 4.6 Severity levels If the purchaser specifies different severity levels in different areas of the same casting, all of these areas shall be clearly identified on the purchaser's drawing and shall include: ¾ all necessary dimensions for accurate location of zones; ¾ the full extent of all weld preparations and the thickness of any special rim zone. Severity level 1 is only applied to weld preparations and special rim zones. Unless other requirements have been agreed by the time of acceptance of the order, for finishing welds, the re- quirements for the parent metal shall apply. 5 Examination 5.1 Principles The principles of ultrasonic examination given in EN 583-1, EN 583-2 and EN 583-5 shall apply. 5.2 Material The suitability of material for ultrasonic examination is assessed by comparison with the echo height of a reference reflector (usually the first backwall echo) and the noise signal. This assessment shall be carried out on selected casting areas which are representative of the surface finish and of the total thickness range. The assessment areas shall have parallel surfaces. The reference echo height according to Table 2 shall be at least 6 dB above the noise signal. If the echo height of this smallest detectable flat-bottomed or equivalent side-drilled hole diameter at the end of the test range to be assessed is less than 6 dB above the grass level, then the ultrasonic testability is reduced. In this case, the flat-bottomed or side-drilled hole diameter which can be detected with a signal-noise ratio of at least 6 dB shall be noted in the test report and the additional procedure shall be agreed between the manufacturer and the purchaser. NOTE For the definition of an adequate flat-bottomed hole size, the distance gain size system (DGS) or a test block of identical material, heat treatment condition and section thickness containing flat-bottomed holes with a diameter according to Table 2 or equivalent side-drilled holes, can be used. The following formula is used for converting the flat-bottomed hole di- ameter into the side-drilled hole diameter: s D D · · = 2 FBH Q l 4935,4 (2) where DQ is the side-drilled hole diameter in millimetres; DFBH is the flat-bottomed hole diameter in millimetres; l is the wave length in millimetres; - - ` , , , , ` , , ` ` ` ` , , , ` , , , ` , ` , , , ` ` , ` - ` - ` , , ` , , ` , ` , , ` - - - EN 12680-1:2003 (E) 8 s is the path length in millimetres. The formula is applicable for DQ ‡ 2 l and s ‡ 5 · near-field length and is only defined for single element probes. 5.3 Equipment and coupling medium 5.3.1 Ultrasonic instrument The ultrasonic instrument shall meet the requirements given in EN 12668-1 and shall have the following character- istics: ¾ range setting, from at least 10 mm to 2 m continuously selectable, for longitudinal and transverse waves transmitted in steel; ¾ gain, adjustable in 2 dB maximum steps over a range of at least 80 dB with a measuring accuracy of 1 dB; ¾ time-base and vertical linearities less than 5 % of the adjustment range of the screen; ¾ suitability at least for nominal frequencies from 1 MHz up to and including 5 MHz in pulse-echo technique with single-crystal and twin-crystal probes. 5.3.2 Probes and transducer frequencies The probes and transducer frequencies shall be as given in EN 12668-2 and EN 12668-3 with the following excep- tions: ¾ nominal frequencies shall be in the range 1 MHz to 5 MHz; ¾ for oblique incidence, angle probes with angles between 35° and 70° shall be used. NOTE Normal or angle probes can be used for the examination of steel castings. The type of probe used depends on the geometry of the casting and the type of discontinuity to be detected. For examining zones close to the surface, twin-crystal probes (normal or angle) should be preferred. 5.3.3 Checking the ultrasonic examination equipment The ultrasonic examination equipment shall be checked regularly by the operator according to EN 12668-3. 5.3.4 Coupling medium A coupling medium in accordance with EN 583-1 shall be used. The coupling medium shall wet the examination area to ensure satisfactory sound transmission. The same coupling medium shall be used for calibration and all subsequent examination operations. NOTE The sound transmission can be checked by ensuring one or more stable backwall echoes in areas with parallel surfaces. 5.4 Preparation of casting surfaces for examination For the preparation of casting surfaces for examination see EN 583-1. The casting surfaces to be examined shall be such that satisfactory coupling with the probe can be achieved. In the case of single-crystal probes, satisfactory coupling can be achieved if the condition of the surfaces to be ex- amined corresponds at least to the