1、BRITISH STANDARDBS EN 14977:2006Copper and copper alloys Detection of tensile stress 5 % ammonia testThe European Standard EN 14977:2006 has the status of a British StandardICS 77.150.30g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g5
2、5g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 14977:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 29 September 2006 BSI 2006ISBN 0 580 49163 3National forewordThis British Standard was publi
3、shed by BSI. It is the UK implementation of EN 14977:2006.The UK participation in its preparation was entrusted to Technical Committee NFE/34, Copper and copper alloys.A list of organizations represented on NFE/34 can be obtained on request to its secretary.This publication does not purport to inclu
4、de all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 14977June 2006I
5、CS 77.150.30English VersionCopper and copper alloys - Detection of tensile stress - 5 %ammonia testCuivre et alliages de cuivre - Dtection des contraintes detraction - Essai lammoniaque 5 %Kupfer und Kupferlegierungen - Auffinden vonZugspannungen - 5 % AmmoniakprfungThis European Standard was approv
6、ed by CEN on 15 May 2006.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 nationalstandar
7、ds may be obtained on application to the Central Secretariat 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
8、Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, P
9、oland, Portugal, Romania,Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2006 CEN All rights of exploitation in any form and by a
10、ny means reservedworldwide for CEN national Members.Ref. No. EN 14977:2006: EEN 14977:2006 (E) 2 Contents Page Foreword3 Introduction .4 1 Scope 5 2 Principle5 3 Terms and definitions .5 4 Test solution.5 5 Test pieces .6 6 Procedure .6 7 Test requirements6 8 Test report 6 Bibliography7 EN 14977:200
11、6 (E) 3 Foreword This document (EN 14977:2006) has been prepared by Technical Committee CEN/TC 133 “Copper and copper alloys”, 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 endorsemen
12、t, at the latest by December 2006, and conflicting national standards shall be withdrawn at the latest by December 2006. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium,
13、 Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 14977:2006 (E) 4 Introduction Thi
14、s test was developed to achieve three aims in particular: firstly to avoid health and environmental risks which are associated with the use of media other than ammonia, (e.g. with the use of compounds of mercury and recovery of mercury polluted test pieces), but with a similar sensitivity as the tes
15、t according to EN ISO 196; secondly to combine a test on tensile stress with a test on stress corrosion cracking; thirdly to reduce the test duration from usually 24 h, as specified in ISO 6957, to 16 h. It is not intended to replace and withdraw EN ISO 196 in favour of this standard. In so far as a
16、 rapid result is required, the test according to EN ISO 196 can be used. EN 14977:2006 (E) 5 1 Scope This standard specifies a medium-duration test using an ammonical atmosphere for the purpose of detecting the presence of tensile stress, residual or applied, in grades of copper or copper-alloy prod
17、ucts that might bring about failure of a component in service or storage through stress corrosion cracking. The field of application of this standard is specified in the technical delivery specifications of semi-finished or finished products in grades of copper and copper alloys, or by prior agreeme
18、nt between purchaser and supplier. 2 Principle Exposure of test pieces to an ammoniacal atmosphere for 16 h, followed by examination at a magnification of 6 to 10, e.g. for cracks. 3 Terms and definitions For the purposes of this European Standard, the following terms and definitions apply. 3.1 stre
19、ss corrosion cracking cracking of metals under the combined action of corrosion and tensile stress, residual or applied 3.2 applied stress tensile stress that is set up and exists in a body during application of an external load 3.3 residual stress tensile stress that remains within a body as a resu
20、lt of plastic deformation 4 Test solution 4.1 General Use only reagents of recognised analytical grade and distilled or deionised water for the test solution. 4.2 Test solution No. 1 The test solution is an aqueous solution containing approx. 50 g NH3per litre of solution, density at 20 C: 0,976 g/m
21、l to 0,978 g/ml. The solution can be used several times, provided that NH3concentration is maintained. 4.3 Test solution No. 2 Dissolve 107 g of pure NH4Cl, suitable for analysis, in approx. 0,75 l of distilled or deionised water, add a solution of 440 g of NaOH per litre until a pH of 10 ( 0,1) at
22、22 C is achieved. Dilute the solution with distilled water to one litre. This does not modify significantly the pH. The test solution can be reused several times, provided the pH is checked at least every two weeks, and corrected if necessary. Because of the consumption of NH4Cl, after every three m
23、onths a new test solution shall be prepared. EN 14977:2006 (E) 6 5 Test pieces The test pieces shall be at least 150 mm long and shall be degreased. Oxide layers, if any, shall be removed by means of 10 %-sulphuric acid solution (mass fraction), produced by diluting 62 ml of concentrated sulphuric a
24、cid ( = 1,84 g/ml), with water up to 1 000 ml. The test pieces shall not be deformed and shall be free from identification stamping or any other mechanical damage. The test pieces shall be dry when the test begins. 6 Procedure Pour the test solution into a desiccator or an air-tight vessel, maintain
25、 the ratio between the volume of the test vessel and the volume of the test solution between 10 : 1 and 20 : 1. The test pieces shall be arranged in the vessel and above the solution so that the vapour can act from all sides. The test pieces shall neither touch each other nor come into direct contac
26、t with the solution. The test temperature shall be between 20 C and 25 C and shall remain constant. The duration of the test shall be 16 h. At the end of the test period, the test pieces shall be briefly pickled in 10 %-sulphuric acid solution (mass fraction) produced by diluting 62 ml of concentrat
27、ed sulphuric acid ( = 1,84 g/ml), with water up to 1 000 ml or 36 %-nitric acid solution (mass fraction), produced by diluting 440 ml of concentrated nitric acid, ( = 1,43 g/ml), with water up to 1 000 ml, dried and examined for cracking under a magnifying glass. The magnification should be between
28、6 and 10. Before inspection, it may be necessary to deform the test piece slightly so that fine cracks are opened up and are more readily seen. Light-gauge test pieces, i.e. pieces with a thickness of less than 2 mm, shall be tested with solution No. 2. Test pieces with a thickness of equal to or gr
29、eater than 2 mm shall be tested with solution No. 1. 7 Test requirements The interpretation of the visual appearance of the test pieces (e.g. existence of cracks) after testing is a matter for the product specification and/or has to be agreed between the purchaser and the supplier, e.g. no crack sha
30、ll be visible on the surface of the test piece when examined under low power magnification. Cracks within a 5 mm wide zone along cut or sawn edges, or around stamped markings, originating from the test piece preparation shall be disregarded. 8 Test report The test report shall include the following
31、information: a) identification of the sample, and the location of the test piece in the sample if the test was carried out on a test piece taken from the sample, rather than on the sample itself; b) reference of the test method used; c) pH-value of the solution producing the ammonical atmosphere; d)
32、 exposure temperature; e) number of replicate test pieces tested; f) test results: cracks or no cracks (as required in the appropriate product specification); g) any unusual features noted during the determination; h) any operation not included in this European Standard or in the document to which r
33、eference is made or regarded as optional; i) date of the test and/or date of preparation or signature of the test report. EN 14977:2006 (E) 7 Bibliography In the preparation of this European Standard, use was made of a number of documents for reference purposes. The relevant publications are listed
34、hereafter. 1 ASTM G 37 98, Standard Practice for Use of Mattssons Solution of pH 7.2 to Evaluate the Stress-Corrosion Cracking Susceptibility of Copper-Zinc Alloys 2 EN ISO 196, Wrought copper and copper alloys Detection of residual stress Mercury(I)nitrate test (ISO 196:1978). 3 ISO 6957, Copper al
35、loys Ammonia test for stress corrosion resistance. 4 Mattsson, E., Holm, R. and Hassel, L.: Ammonia Test for Stress Corrosion Resistance of Copper Alloys 5 Sick, H., Werkstoffe und Korrosion 38, 356-358 (1978). BS EN 14977:2006BSI389 Chiswick High RoadLondonW4 4ALBSI British Standards InstitutionBSI
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