en 12680-3_2003

8/20/2019 EN 12680-3_2003

http://slidepdf.com/reader/full/en-12680-32003 1/20

BRITISH STANDARD BS EN12680-3:2003

Founding — Ultrasonicexamination —

Part 3: Spheroidal graphite cast ironcastings

The European Standard EN 12680-3:2003 has the status of aBritish Standard

ICS 77.040.20

opyright British Standards Institutionovided by IHS under license with BSI - Uncontrolled Copy Licensee=Alstom Industrial GAs Turbines/5941029100

Not for Resale, 11/24/2006 02:38:01 MSTo reproduction or networking permitted without license from IHS

--`,,,,`,,``,,`,,`,`,,,``,,`,`,-̀-`,,`,,`,`,,`---

8/20/2019 EN 12680-3_2003


BS EN 12680-3:2003

This British Standard waspublished under the authorityof the Standards Policy andStrategy Committee on5 February 2003

© BSI 5 February 2003

ISBN 0 580 41200 8

National foreword

This British Standard is the official English language version ofEN 12680-3:2003.

The UK participation in its preparation was entrusted to Technical CommitteeISE/NFE/9, Foundry technology, which has the responsibility to:

A list of organizations represented on this committee can be obtained onrequest to its secretary.

Cross-references

The British Standards which implement international or Europeanpublications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, orby using the “Search” facility of the BSI Electronic Catalogue or of BritishStandards Online.

This publication does not purport to include all the necessary provisions of acontract. Users are responsible for its correct application.

Compliance with a British Standard does not of itself confer immunityfrom legal obligations.

— aid enquirers to understand the text;

— present to the responsible international/European committee anyenquiries on the interpretation, or proposals for change, and keep theUK interests informed;

— monitor related international and European developments andpromulgate them in the UK.

Summary of pagesThis document comprises a front cover, an inside front cover, the EN title page,pages 2 to 16, an inside back cover and a back cover.

The BSI copyright date displayed in this document indicates when thedocument was last issued.

Amendments issued since publication

Amd. No. Date Comments



--`

, , , ,`

, ,` `

, ,`

, ,`

,`

, , ,` `

, ,`

,`

,-` -`

, ,`

, ,`

,`

, ,` ---

8/20/2019 EN 12680-3_2003


EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORM

EN 12680-3

January 2003

ICS 77.040.20

English version

Founding - Ultrasonic examination - Part 3: Spheroidal graphitecast iron castings

Fonderie - Contrôle par ultrasons - Partie 3: Piècesmoulées en fonte à graphite sphéroïdal

Gießereiwesen - Ultraschallprüfung - Teil 3: Gussstückeaus Gusseisen mit Kugelgraphit

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 EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards 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 translationunder the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the officialversions.

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 UnitedKingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATIONC O M I T É E U R O P É E N D E N O R M A L I S AT I O NEUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: rue de Stassart, 36 B-1050 Brussels

© 2003 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.

Ref. No. EN 12680-3:2003 E



- -

` , , , ,

` , ,

` `

, ,

` , ,

` ,

` , , ,

` `

, ,

` ,

` ,

- `

- `

, ,

` , ,

` ,

` , ,

` - - -

8/20/2019 EN 12680-3_2003


EN 12680-3:2003 (E)

2

Contents

page

Foreword......................................................................................................................................................................31 Scope ..............................................................................................................................................................4

2 Normative references ....................................................................................................................................4

3 Terms and definitions....................................................................................................................................4

4 Requirements .................................................................................................................................................54.1 Order information ..........................................................................................................................................54.2 Extent of examination....................................................................................................................................54.3 Maximum permissible size of discontinuities.............................................................................................54.4 Personnel qualification .................................................................................................................................54.5 Wall section zones.........................................................................................................................................5

5 Test method....................................................................................................................................................55.1 Principles ........................................................................................................................................................55.2 Material............................................................................................................................................................55.3 Equipment, coupling medium, calibration and sensitivity ........................................................................65.4 Preparation of casting surfaces for examination .......................................................................................85.5 Examination procedure.................................................................................................................................85.6 Examination report ......................................................................................................................................10

Bibliography ..............................................................................................................................................................16



- -

` , , , ,

` , ,

` `

, ,

` , ,

` ,

` , , ,

` `

, ,

` ,

` ,

- `

- `

, ,

` , ,

` ,

` , ,

` - - -

8/20/2019 EN 12680-3_2003


EN 12680-3:2003 (E)

3

Foreword

This document (EN 12680-3:2003) 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 orby endorsement, at the latest by July 2003, and conflicting national standards shall be withdrawn at the latest byJuly 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 12680-3, Founding — Ultrasonic examination — Part 3: Spheroidal graphite cast iron castings.

This is one of three European Standards for ultrasonic examination. The other standards are:

EN 12680-1, Founding — Ultrasonic examination — Part 1: Steel castings for general purposes.

EN 12680-2, Founding — Ultrasonic examination — Part 2: Steel castings for highly stressed components.

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, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal,Slovakia, Spain, Sweden, Switzerland and the United Kingdom.



--`

, , , ,`

, ,` `

, ,`

, ,`

,`

, , ,` `

, ,`

,`

,-` -`

, ,`

, ,`

,`

, ,` ---

8/20/2019 EN 12680-3_2003


EN 12680-3:2003 (E)

4

1 Scope

This European Standard specifies the requirements for the ultrasonic examination of spheroidal graphite cast ironcastings and the methods for determining internal discontinuities by the pulse-echo technique.

This European Standard does not deal with the ultrasonic examination of the nodularity of spheroidal graphite castirons.

This European Standard does not cover the transmission technique.

NOTE The transmission technique has insufficient sensitivity to detect the discontinuities found in spheroidal graphite castiron castings and is used in exceptional cases only.

2 Normative references

This European Standard incorporates by dated or undated reference, provisions from other publications. Thesenormative references are cited at the appropriate places in the text, and the publications are listed hereafter. Fordated references, subsequent amendments to or revisions of any of these publications apply to this EuropeanStandard only when incorporated in it by amendment or revision. For undated references the latest edition of thepublication 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 583-3, Non-destructive testing — Ultrasonic examination — Part 3: Transmission technique.

EN 583-5, Non-destructive testing — Ultrasonic examination — Part 5: Characterization and sizing of discontinuities.

EN 1330-4, Non-destructive testing — Terminology — Part 4: Terms used in ultrasonic testing.

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).

NOTE Informative references to documents used in the preparation of this standard, and cited at the appropriate places inthe text, are listed in the bibliography.

3 Terms and definitions

For the purposes of this European Standard, the terms and definitions given in EN 1330-4 apply.



- -

` , , , ,

` , ,

` `

, ,

` , ,

` ,

` , , ,

` `

, ,

` ,

` ,

-

` -

` , ,

` , ,

` ,

` , ,

` - - -

8/20/2019 EN 12680-3_2003


EN 12680-3:2003 (E)

5

4 Requirements

4.1 Order information

The following information shall be available at the time of enquiry and order (see also EN 583-1):

the areas of the casting and the number or percentage of castings to which the ultrasonic examination require-ments apply;

the severity levels in accordance with Tables 1 and 2 to be applied to the various areas of the casting;

requirements for a written examination procedure.

4.2 Extent of examination

The areas of the casting to be examined shall be agreed. This agreement shall state how these areas are to beexamined, i.e. point testing or scanning, and in which directions.

NOTE These areas should be preferably indicated on the casting drawing.

For wall thicknesses outside of the range 10 mm to 500 mm, agreement shall be made between the parties con-cerned on the examination procedure and also on the recording and acceptance levels.

4.3 Maximum permissible size of discontinuities

Unless otherwise agreed between the parties concerned, the maximum permissible sizes of discontinuities shallnot exceed those of the severity level given in either Table 1 (shrinkage) and/or Table 2 (dross).

4.4 Personnel qualification

It is assumed that ultrasonic examination is performed by qualified and capable personnel. In order to prove thisqualification, it is recommended to certify personnel in accordance with EN 473.

4.5 Wall section zones

The wall section shall be divided into zones as shown in Figure 1.

NOTE These wall sections relate to the dimensions of the casting ready for assembly (finish machined).

5 Test method

5.1 Principles

The principles given in EN 583-1, EN 583-2 and EN 583-3 shall apply.

5.2 Material

The suitability of a material for ultrasonic examination is assessed by comparison with the echo height of a refer-ence reflector (usually the first back wall echo) and the noise signal. This assessment shall be carried out on se-lected casting areas which are representative of the surface finish and of the total thickness range. The assess-ment areas shall have parallel surfaces.

The reference echo height shall be at least 6 dB above the noise signal.



- -

` , , , ,

` , ,

` `

, ,

` , ,

` ,

` , , ,

` `

, ,

` ,

` ,

- `

- `

, ,

` , ,

` ,

` , ,

` - - -

8/20/2019 EN 12680-3_2003


EN 12680-3:2003 (E)

6

If the echo height of this smallest detectable flat-bottomed or equivalent side-drilled hole diameter at the end of thetest range to be assessed is less than 6 dB above the grass level, then the ultrasonic testability is reduced. In thiscase, the flat-bottomed or side-drilled hole diameter which can be detected with a signal-noise ratio of at least 6 dBshall be noted in the examination report and the additional procedure shall be agreed between the manufacturerand the purchaser.

NOTE If a distance gain size diagram (DGS) is available, the suitability of castings for ultrasonic examination with normalprobes can be determined for example as follows: with the suppression switched off, the backwall echo is brought to any refer-ence level desired. The amplification according to the DGS diagram is then increased so that the echo signal height from thesubstitute reflector according to 5.3.5.3 reaches the reference level. If the amplification is further increased by 6 dB the back-ground noise level should not exceed the reference height. If necessary, a reference reflector can be used to determine thetesting suitability in areas without the backwall echo.

5.3 Equipment, coupling medium, calibration and sensitivity

5.3.1 Ultrasonic instrument

The ultrasonic instrument shall meet the requirements given in EN 12668-1 and shall have the following character-istics:

range setting, from at least 10 mm to 2 m continuously selectable, for longitudinal and transverse wavestransmitted in steel;

gain, adjustable in 2 dB maximum steps over a range of at least 80 dB with a measuring accuracy of 1 dB;

time-base and vertical linearities less than 5 % of the adjustment range of the screen;

suitability at least for nominal frequencies from 0,5 MHz up to and including 5 MHz in pulse-echo techniquewith 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:

to cover the range of discontinuity types to be detected, the casting can be examined using compression-wavesingle-crystal or twin-crystal probes.

NOTE 1 Twin-crystal probes should be used for the examination of areas close to the test surface.

for special geometrical conditions, angle probes can be used up to a sound-beam path length of about100 mm, preferably with nominal angles between 45° and 70°. The frequency value shall be selected to suitthe examination and shall be within the range 0,5 MHz to 5 MHz. Higher frequencies can be used for examin-ing wall thicknesses of less than 20 mm or areas close to the surface.

NOTE 2 For the detection of near-surface discontinuities, the use of twin-crystal and/or angle probes is recommended.

NOTE 3 Since sound travels at different velocities in steel and spheroidal graphite cast iron, the actual angle of refractiondeviates from the nominal angle of the probe for steel.

If the sound velocity of spheroidal graphite cast iron is known, the angle of refraction of the probe can be deter-mined from the sound velocity according to Figure 2.

Figure 3 shows how the angle of refraction can be determined to an accuracy sufficient for practical purposes usingtwo probes of the same type. The sound velocity of spheroidal graphite cast iron can also be determined from theangle of refraction α as follows:

s

cc α

α

sinsin

2553 ×=C (1)



--`,,,,`,,``,,`,,`,`,,,``,,`,`,--̀`,,`,,`,`,,`---

8/20/2019 EN 12680-3_2003


EN 12680-3:2003 (E)

7

where

C c the sound velocity in the casting in metres per second;

α c is the angle of refraction in the casting in degrees;

α s is the angle of refraction in steel in degrees.

NOTE 4 To simplify examination, special probes can be used, e.g. angle probes for longitudinal waves.

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 allsubsequent examination operations.

NOTE The sound transmission can be checked by ensuring one or more stable backwall echoes in areas with parallelsurfaces.

5.3.5 Calibration of the ultrasonic equipment

5.3.5.1 General

A spheroidal graphite cast iron reference block shall be used for calibration. The thickness of the reference blockshall be comparable to the wall thickness range of the casting to be examined and shall be agreed at the time ofenquiry and order. The reference block shall have the same ultrasonic properties as the casting to be examinedand shall have the same surface finish. The reference block shall contain flat-bottomed holes according to Table 3or equivalent side-drilled holes as substitute reflectors.

NOTE The following formula is used for converting the flat-bottomed hole diameter into the side-drilled hole diameter:

s

D D

×

×=

2

4935,4λ

FBHQ (2)

where

D Q is the side-drilled hole diameter in millimeter;

D FBH is the flat-bottomed hole diameter in millimeter;

λ is the wave length in millimeter;

s is the path length in millimeter.

The formula is applicable for D Q ≥ 2 λ and s ≥ 5 × nearfield length and is only defined for single element probes.

Other substitute reflector sizes or reflector types may be agreed at the time of enquiry and order. All sound of thereference block shall be flat and parallel. If standard steel calibration blocks are used, differences in sound velocity,sound attenuation and surface quality between the casting and the calibration blocks shall be taken into consider-ation.

The equipment can also be set using a DGS diagram [1] (see bibliography) calculated for spheroidal graphite castiron. In this case, the reference block is not necessary and calibration can be done on the casting itself.



- -

` , , , ,

` , ,

` `

, ,

` , ,

` ,

` , , ,

` `

, ,

` ,

` ,

- `

- `

, ,

` , ,

` ,

` , ,

` - - -

8/20/2019 EN 12680-3_2003


EN 12680-3:2003 (E)

8

5.3.5.2 Range setting

Range setting shall be carried out. It can be done either on the reference block or calibration block and checked onthe casting itself or carried out directly on the casting, if its thickness is known and if it has parallel surfaces.

5.3.5.3 Sensitivity setting

The sensitivity shall be set by reflecting sound from a suitable reflector, e.g. the opposite surface of a casting, a flat-bottomed or side-drilled hole of the reference block or the circular segments of the calibration blocks K1 accordingto EN 12223 or K2 according to EN 27963. Account shall be taken of the sound attenuation, surface quality andvelocity of sound through the casting. The transfer correction shall be determined. When determining the transfercorrection, not only the quality of the coupling areas but also the surface quality of the opposite surface shall betaken into consideration. The signal level in the thickness range to be assessed is given by the diameter in millime-tres of any suitable reflector (see 5.3.5.1)

NOTE A reference curve can be taken on the substitute reflectors of the reference block and transferred to the instrumentscreen. In order to prevent incorrect evaluation of the signals for different path lengths, the reference curve should be correctedto take into account different sound attenuations between the reference block and the casting.

5.3.6 Detection sensitivity

The detection sensitivity of the equipment shall ensure at least the setting of the sensitivity in accordance with therequirements of 5.5.3.

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.

NOTE It is recommended that surface condition requirements according to EN 1370 are agreed at the time of enquiry andorder (e.g. as-cast, shot-blasted, fettled or machined surfaces).

5.5 Examination procedure

5.5.1 General

The selection of the incidence direction and of the most suitable probes depends largely on the casting shape andthe nature and position of the casting discontinuities. Therefore, the applicable examination procedure shall bespecified by the manufacture of the casting and the operator as applicable. The method most widely used is verticalincidence with compression wave probes having frequencies within the range 0,5 MHz up to and including 5 MHz.Single-crystal or twin-crystal probes can be used. Oblique incidence (angle probes) can be used for special geo-

metrical conditions, where compression wave probes are not satisfactory. If the intended application of the castingneeds special requirements regarding the examination procedure, the purchaser shall inform the manufacturer ac-cordingly.

NOTE Higher frequencies are normally used to examine castings with small wall thicknesses and high-quality require-ments.

Complete coverage of all areas specified for scanning shall be conducted by carrying out systematicallyover-lapping scans.

If scanning is agreed (see 4.2), the scanning rate shall not exceed 150 mm/s.



- -

` , , , ,

` , ,

` `

, ,

` , ,

` ,

` , , ,

` `

, ,

` ,

` ,

- `

- `

, ,

` , ,

` ,

` , ,

` - - -

8/20/2019 EN 12680-3_2003


EN 12680-3:2003 (E)

9

5.5.2 Sensitivity setting

5.5.2.1 Minimum sensitivity (detection sensitivity)

The sensitivity of the system shall be set in such a way that the echo heights of the flat-bottomed holes given inTable 3 or of the equivalent side-drilled holes shall be at least 40 % of the screen height at the end of the thicknessrange to be examined. If it is not possible to set this minimum sensitivity, the smallest flat-bottomed hole which canbe detected shall be recorded in the examination report. In this case, the purchaser and the manufacturer shallagree on further action.

5.5.2.2 Search sensitivity

When searching for discontinuities, the amplification shall be set in such a way that the noise level is visible on thescreen (search sensitivity).

If there are local variations in surface quality, the sensitivity can fluctuate widely. In such cases, the search sensi-tivity shall not fall below the minimum sensitivity.

NOTE For discontinuity searching with simultaneous observation of the backwall echo (see Table 4), the use of deviceswith adjustable backwall echo reduction is advantageous.

5.5.3 Consideration of various types of indications

The following types of indications, which are proven not to be due to the casting shape or the coupling, shall betaken into consideration and evaluated in the examination of castings:

reduction of the backwall echo;

intermediate echoes.

NOTE All types of indications can occur alone or together. Backwall echo reduction is expressed as a decrease in backecho in decibels; the height of an echo indication is given as a flat-bottomed hole or side-drilled hole diameter (see EN 583-2).

5.5.4 Evaluation and recording of indications

Unless otherwise agreed, all backwall echo reductions or echo heights reaching or exceeding the limits given inTable 4 shall be evaluated and shall be recorded if their values exceed 75 % of the limits given in Tables 1 and 2.Whenever such indications are found, their location shall be indicated and included in the examination report (see5.6). The location of the indications to be recorded can be described using grids, sketches or photographs.

In case of simultaneous indications according to Tables 1 and 2, the procedure shall be agreed between the con-tracting parties.

5.5.5 Investigation of indications to be recorded

The locations where indications to be recorded have been found (see 5.5.4) shall be investigated more closely withrespect to their type, shape, size and position. This can be achieved by altering the transducer frequency or by al-tering the examination procedure or by using other examination methods such as radiography.

5.5.6 Sizing of discontinuities

5.5.6.1 General

The methods of sizing of the dimensions of discontinuities given in 5.5.6.2 and 5.5.6.3 shall be used according to

EN 583-5.

NOTE The dimensions of a discontinuity determined by ultrasonic examination can only be measured to an accuracy suffi-cient for technical applications under certain preconditions (e.g. knowledge of the type of the discontinuity, simple geometry of



--`,,,,`,,``,,`,,̀,`,,,``,,`,`,-`-̀,,`,,`,`,,`---

8/20/2019 EN 12680-3_2003


EN 12680-3:2003 (E)

10

the discontinuity, optimum impact of the sound beam on the discontinuity). These preconditions are often not present in sphe-roidal graphite cast iron.

5.5.6.2 Determination of the dimensions of discontinuities mainly parallel to the examination surface

In order to determine the dimensions of discontinuities mainly parallel to the examination surface, it is recom-mended that probes with the smallest possible sound-beam diameter at the discontinuity location are used.

For the determination of the dimensions of discontinuities which shall be recorded according to Table 1 on accountof their echo height (see Table 4), the probe shall be moved over the examination area to identify those pointswhere the signal amplitude falls to 6 dB below the last maximum.

For backwall echo reduction, the probe shall be moved over the examination surface to identify those points wherethe backwall echo is reduced by 12 dB or 20 dB according to Table 4.

In both cases, the points shall be marked as accurately as possible (e.g. probe centre for normal probes, probeindex point for angle probes).

The measurable dimensions of the discontinuity are given by a connecting line between the marked points. Withangle probes, the edge points of the discontinuities shall be projected onto the examination surface so far as thecasting geometry allows.

5.5.6.3 Determination of the dimensions of discontinuities in through-wall direction

As far as possible, dimensions of discontinuities in through-wall direction to the examination area are measuredusing normal probes from opposite sides (see Figure 4).

5.6 Examination report

The examination report shall contain at least the following information:

reference to this European Standard (EN 12680-3);

characteristic data of the examined casting;

extent of examination;

type of examination equipment used;

probes used

examination technique with reference to the examined area;

all data necessary for the sensitivity setting;

details of ultrasonic examination suitability;

information on all characteristic features of discontinuities to be recorded (e.g. backwall echo reduction, posi-tion and dimension in through-wall direction, length, area and flat-bottomed hole diameter) and the descriptionof their position (sketch or photograph);

date of the examination and name of the responsible person.



- -

` , , , ,

` , ,

` `

, ,

` , ,

` ,

` , , ,

` `

, ,

` ,

` ,

- `

- `

, ,

` , ,

` ,

` , ,

` - - -

8/20/2019 EN 12680-3_2003


Table 1 — Maximum permissible indicated dimensions of discontinuities — volumetric reflectors

Severity levelFeature Unit

1 2 3 4

Wall thickness,in the examined area mm — < 50 50 to 200 > 200 < 50 50 to 200 > 200 < 50 50 to 200 > 2

Percentage of wallthickness % — 20 25 30

Largest discontinuity inthe rim zone a, b mm 2 c 600 1 000 1 000 1 000 2 000 2 000 — —

Largest discontinuity inthe core zone mm 2 c 10 000 15 000 15 000 15 000 20 000 30 000 20 000 — —

Total area of disconti-nuities as percentage ofexamined surface

% c 10 15 15 15 20 20 15 20

a For dross see Table 2.

b Rim zone, see Figure 1.

c No indications exceeding the limits given in Table 4.

C o p y r i gh

t B r i t i s h

S t an

d ar d

s I n

s t i t u t i on

P r ov i d

e d b y I H

S un

d er l i c

en

s ewi t h B

S I -

U n

c on

t r ol l e

d C o p y

L i c en

s e e=A l s t om I n

d u s t r i al GA

s T

ur b i n

e s / 5 9 4 1

0 2

9 1

0 0

M

--`,,,,`,,``,,`,,̀,`,,,``,,`,`,-`-̀,,`,,`,`,,`---

8/20/2019 EN 12680-3_2003


EN 12680-3:2003 (E)

12

Table 2 — Maximum permissible indicated dimensions of discontinuities — dross

Severity levelFeature

1 2 3 4 5

Percentage of wallthickness in %

a 10 15 20 25

a No indications exceeding the limits given in Table 4.

Table 3 — Requirements for ultrasonic examination suitability

Dimensions in millimetres

Wall thickness of the castingin the examined area

Smallest flat-bottom hole diameterdetectable according to 5.2

> 10 to 20 3

> 20 to 100 5

> 100 to 250 8

> 250 to 500 10

Table 4 — Ultrasonic indications to be evaluated

Evaluation limits

reduction of backwallecho

smallest flat-bottomhole diameter detectable

according to 5.2

echo heightabove noise level a

Wall thicknessof the casting

in the examined area

min. min.

mm dB mm dB

> 10 to 20 12 3

> 20 to 100 5 6

> 100 to 250 8

> 250 to 500

20

1012

a Only for areas where no backwall echo is obtained to the casting geometry.



--`

, , , ,`

, ,` `

, ,`

, ,`

,`

, , ,` `

, ,`

,`

,-` -`

, ,`

, ,`

,`

, ,` ---

8/20/2019 EN 12680-3_2003


EN 12680-3:2003 (E)

13

Key1 Rim zone2 Core zone

t Wall thicknessa t /3 (max. 30 mm)

Figure 1 — Division of wall section into zones

Keya Angle of refraction α c in spheroidal graphite cast ironb Sound velocity of transverse wave c trans in metres per secondc Nominal angle of refraction in steeld Longitudinal and transverse wave simultaneously

Figure 2 — Determination of the nominal angle of refraction in spheroidal graphite cast ironfor an angle probe with known angle of refraction in steel



--`,,,,`,,``,,`,,̀,`,,,``,,`,`,-`-̀,,`,,`,`,,`---

8/20/2019 EN 12680-3_2003


EN 12680-3:2003 (E)

14

t

A

×=

2tanarccα

where

α c is the angle of refraction in the casting;

A is the distance between the probe indexes of the angle probes at maximum signal;

t is the wall thickness.

Key1 Angle beam probes of same type2 Test piece or reference block

Figure 3 — Determination of the angle of refraction in spheroidal graphitecast iron using angle probes



--`

, , , ,`

, ,` `

, ,`

, ,`

,`

, , ,` `

, ,`

,`

,-` -`

, ,`

, ,`

,`

, ,` ---

8/20/2019 EN 12680-3_2003


EN 12680-3:2003 (E)

15

Keya Scanning position Ab Scanning position Bc A scan from scanning position Ae A scan from scanning position B

Dimension in through-wall direction d = t - ( s 1 + s 2)

where

s 1, s 2 are the lengths of the sound-beam paths;

t is the wall thickness.

Figure 4 — Determination of the dimensions of discontinuities in through-wall directionusing normal probes



--`,,,,`,,``,,`,,̀,`,,,``,,`,`,-`-̀,,`,,`,`,,`---

8/20/2019 EN 12680-3_2003


EN 12680-3:2003 (E)

16

Bibliography

[1] Krautkrämer, J. und Krautkrämer, H., Werkstoffprüfung mit Ultraschall, Springer Verlag — Berlin, Heidel-berg, New York, London, Paris, Tokyo, 1986.

[2] EN 473, Non destructive testing — Qualification and certification of NDT personnel — General principles.

[3] EN 1370, Founding — Surface roughness inspection by visualtactile comparators.



- -

` , , , ,

` , ,

` `

, ,

` , ,

` ,

` , , ,

` `

, ,

` ,

` ,

- `

- `

, ,

` , ,

` ,

` , ,

` - - -

8/20/2019 EN 12680-3_2003


blankopyright British Standards Institutionovided by IHS under license with BSI - Uncontrolled Copy Licensee=Alstom Industrial GAs Turbines/5941029100


--`

, , , ,`

, ,` `

, ,`

, ,`

,`

, , ,` `

, ,`

,`

,-` -`

, ,`

, ,`

,`

, ,` ---

8/20/2019 EN 12680-3_2003


BS EN12680-3:2003

BSI

389 Chiswick High Road

London

W4 4AL

BSI — British Standards InstitutionBSI is the independent national body responsible for preparingBritish Standards. It presents the UK view on standards in Europe and at theinternational level. It is incorporated by Royal Charter.

Revisions

British Standards are updated by amendment or revision. Users ofBritish Standards should make sure that they possess the latest amendments oreditions.

It is the constant aim of BSI to improve the quality of our products and services.We would be grateful if anyone finding an inaccuracy or ambiguity while usingthis British Standard would inform the Secretary of the technical committeeresponsible, the identity of which can be found on the inside front cover.Tel: +44 (0)20 8996 9000. Fax: +44 (0)20 8996 7400.

BSI offers members an individual updating service called PLUS which ensuresthat subscribers automatically receive the latest editions of standards.

Buying standards

Orders for all BSI, international and foreign standards publications should beaddressed to Customer Services. Tel: +44 (0)20 8996 9001.Fax: +44 (0)20 8996 7001. Email: [email protected]. Standards are alsoavailable from the BSI website at http://www.bsi-global.com .

In response to orders for international standards, it is BSI policy to supply theBSI implementation of those that have been published as British Standards,unless otherwise requested.

Information on standards

BSI provides a wide range of information on national, European andinternational standards through its Library and its Technical Help to ExportersService. Various BSI electronic information services are also available which give

details on all its products and services. Contact the Information Centre.Tel: +44 (0)20 8996 7111. Fax: +44 (0)20 8996 7048. Email: [email protected].

Subscribing members of BSI are kept up to date with standards developmentsand receive substantial discounts on the purchase price of standards. For detailsof these and other benefits contact Membership Administration.Tel: +44 (0)20 8996 7002. Fax: +44 (0)20 8996 7001.Email: [email protected].

Information regarding online access to British Standards via British StandardsOnline can be found at http://www.bsi-global.com/bsonline .

Further information about BSI is available on the BSI website athttp://www.bsi-global.com.

CopyrightCopyright subsists in all BSI publications. BSI also holds the copyright, in theUK, of the publications of the international standardization bodies. Except aspermitted under the Copyright, Designs and Patents Act 1988 no extract may bereproduced, stored in a retrieval system or transmitted in any form or by anymeans – electronic, photocopying, recording or otherwise – without prior writtenpermission from BSI.

This does not preclude the free use, in the course of implementing the standard,of necessary details such as symbols, and size, type or grade designations. If thesedetails are to be used for any other purpose than implementation then the priorwritten permission of BSI must be obtained.

Details and advice can be obtained from the Copyright & Licensing Manager.Tel: +44 (0)20 8996 7070. Fax: +44 (0)20 8996 7553.Email: [email protected].

--`

, , , ,`

, ,` `

, ,`

, ,`

,`

, , ,` `

, ,`

,`

,-` -`

, ,`

, ,`

,`

, ,` ---

en 12680-3_2003

Documents