1、BSI Standards PublicationBS ISO 3160-2:2015W a t c h - c a s e s a n d a c c e s s o r i e s Gold alloy coveringsPart 2: Determination of fineness, thickness,corrosion resistance and adhesionBS ISO 3160-2:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 316
2、0-2:2015.It supersedes BS ISO 3160-2:2003 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee STI/53, Specifications and test methods for jewellery andhorology.A list of organizations represented on this committee can beobtained on request to its secretary.
3、This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2015.Published by BSI Standards Limited 2015ISBN 978 0 580 86134 5ICS 39.040.10Compliance with a British Standard cannot confer
4、immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 December 2015.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dBS ISO 3160-2:2015 ISO 2015Watch-cases and accessories Gold alloy coverin
5、gs Part 2: Determination of fineness, thickness, corrosion resistance and adhesionBotes de montres et leurs accessoires Revtements dalliage dor Partie 2: Dtermination du titre, de lpaisseur, de la rsistance la corrosion et de ladhrenceINTERNATIONAL STANDARDISO3160-2Fourth edition2015-12-15Reference
6、numberISO 3160-2:2015(E)BS ISO 3160-2:2015ISO 3160-2:2015(E)ii ISO 2015 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2015, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means,
7、electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Ve
8、rnier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 3160-2:2015ISO 3160-2:2015(E)Foreword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 General 25 Determination of gold fineness . 25.1 General . 25.2 Methods of gold f
9、ineness determination 26 Determination of thickness . 37 Determination of the corrosion resistance . 37.1 Forms of corrosion 37.2 Sampling and preparation . 47.2.1 General 47.2.2 Test of finished items (ready-for-use condition) . 47.2.3 Test of coating process (without passivation treatment) . 47.2.
10、4 Non-significant surfaces 47.3 Continuity of the covering (porosity test) . 47.3.1 General 47.3.2 Test for a copper-containing base metal with or without nickel, and die-cast zinc-based alloys 47.3.3 Test a ferrous base metal 57.3.4 Non-determination of base metal . 67.3.5 Testing with nitric acid
11、vapour 67.4 Synthetic perspiration test . 67.4.1 Test vessel 67.4.2 Test solution. 67.4.3 Position of the sample . 67.4.4 Temperature during the test 67.4.5 Duration of the test 67.5 Neutral saline mist test 77.5.1 General 77.5.2 Criteria 77.6 Test of the effects of agents containing sulfur 77.6.1 T
12、hioacetamide test . 77.6.2 Flowers of sulfur test in a moist atmosphere . 78 Adhesion test 7Annex A (normative) Method of obtaining a sample of gold alloy covering 8Annex B (normative) Implementation of the reference methods for the determination of gold alloy coating fineness 10Annex C (normative)
13、Description of the main tests for determination of the thickness of gold alloy coverings 12Bibliography .14 ISO 2015 All rights reserved iiiContents PageBS ISO 3160-2:2015ISO 3160-2:2015(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standard
14、s bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organiz
15、ations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document and those intended for its fur
16、ther maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directi
17、ves). Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the I
18、ntroduction and/or on the ISO list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related
19、to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for this document is ISO/TC 114, Horology, Subcommittee SC 6, Precious metal cover
20、ings.This fourth edition cancels and replaces the third edition (ISO 3160-2:2003), of which it constitutes a technical revision.ISO 3160 consists of the following parts, under the general title Watch-cases and accessories Gold alloy coverings: Part 1: General requirements Part 2: Determination of fi
21、neness, thickness, corrosion resistance and adhesioniv ISO 2015 All rights reservedBS ISO 3160-2:2015ISO 3160-2:2015(E)IntroductionGold alloy coatings deposited on watch-cases and their accessories have to comply with technical, decorative requirements and have to also satisfy national rules about p
22、recious metals.This part of ISO 3160 aims to specify coating characterization methods to qualify their corrosion resistance and their adhesion to the substrate concerning esthetical and technical aspects, and to specify methods to determine thickness and gold fineness of these coatings to check that
23、 they satisfy the requirements of ISO 3160-1. ISO 2015 All rights reserved vBS ISO 3160-2:2015BS ISO 3160-2:2015Watch-cases and accessories Gold alloy coverings Part 2: Determination of fineness, thickness, corrosion resistance and adhesion1 ScopeThis part of ISO 3160 specifies methods to determine
24、fineness, thickness, corrosion resistance and adhesion for gold alloy coverings on watch-cases and accessories, including bracelets when they are permanently attached to the case.The tests apply only to significant surfaces.This part of ISO 3160 applies to all gold alloy coverings specified in ISO 3
25、160-1.2 Normative referencesThe 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
26、amendments) applies.ISO 1463, Metallic and oxide coatings Measurement of coating thickness Microscopical methodISO 2177, Metallic coatings Measurement of coating thickness Coulometric method by anodic dissolutionISO 3160-1, Watch-cases and accessories Gold alloy coverings Part 1: General requirement
27、sISO 3497, Metallic coatings Measurement of coating thickness X-ray spectrometric methodsISO 3543, Metallic and non-metallic coatings Measurement of thickness Beta backscatter methodISO 3868, Metallic and other non-organic coatings Measurement of coating thicknesses Fizeau multiple-beam interferomet
28、ry methodISO 4538, Metallic coatings Thioacetamide corrosion test (TAA test)ISO 9220, Metallic coatings Measurement of coating thickness Scanning electron microscope methodISO 9227, Corrosion tests in artificial atmospheres Salt spray testsISO 11426, Jewellery Determination of gold in gold jewellery
29、 alloys Cupellation method (fire assay)ISO 12687, Metallic coatings Porosity tests Humid sulfur (flowers of sulfur) testISO 14647, Metallic coatings Determination of porosity in gold coatings on metal substrates Nitric acid vapour testISO 27874, Metallic and other inorganic coatings Electrodeposited
30、 gold and gold alloy coatings for electrical, electronic and engineering purposes Specification and test methods3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.INTERNATIONAL STANDARD ISO 3160-2:2015(E) ISO 2015 All rights reserved 1BS ISO 3160-2:20
31、15ISO 3160-2:2015(E)3.1significant surfacepart of the surface which is to receive the gold alloy covering and which is essential to the appearance and serviceability of the componentNote 1 to entry: When there is no agreement between the supplier and customer, a significant surface is considered to
32、be any surface which can be touched by a 5 mm diameter ball.4 GeneralIn the context of this part of ISO 3160, the term “corrosion” includes tarnishing and oxidation, as well as surface penetration and the effects of the penetration of corrosive agents into porosity and micro-discontinuities of the p
33、rotection.It is generally required that, except where specified to the contrary, gold-alloy-covered surfaces should not have suffered any damage after each of the proposed tests. In practice, however, this condition is never strictly fulfilled and certain minor changes are observed, especially at th
34、e edges of the gold-covered parts. Consequently, interpretation of the results requires a certain amount of common sense and, if necessary, agreement between the supplier and customer. The presence of such almost inevitable faults makes it impossible to sell the tested item as new. In this respect,
35、the tests are therefore to be considered to be destructive.The test methods apply to all gold alloy coverings specified in ISO 3160-1.5 Determination of gold fineness5.1 GeneralIf the fineness is measured on a gold alloy covering which is separated from the base metal, the method used to separate th
36、e gold alloy covering from the base metal shall not affect the fineness of the gold covering to a significant extent.For multilayer coverings, the covering content measured is the mean content, which shall be a minimum of 585 parts per thousand, in accordance with ISO 3160-1.The method of separation
37、 of the sample is specified in Annex A.5.2 Methods of gold fineness determinationAny of the following methods shall be used for the determination of contents:a) chemical analysis by reduction in an aqueous solution of, for example, sulfur dioxide or any other suitable reducing agent;b) analysis by1)
38、 cupellation (fire test) as specified in ISO 11426,2) Energy Dispersive Spectroscopy on Scanning Electron Microscopy (SEM/EDS),3) atomic absorption spectrometry,4) spectrophotometry,5) X-ray spectrometry as specified in ISO 3497,6) plasma emission spectrometry (ICP method);c) touchstone method (only
39、 to be used to evaluate the approximate fineness);2 ISO 2015 All rights reservedBS ISO 3160-2:2015ISO 3160-2:2015(E)d) any other physico-chemical method.Any method used shall be capable of giving an indication of fineness to within an accuracy of 50 parts per thousand.In the event of arbitration, cu
40、pellation and SEM/EDS are the reference methods.The implementation of the two reference methods is described in Annex B.6 Determination of thicknessAny of the following test methods for the determination of the thickness of gold alloy coatings shall be used, provided a measuring accuracy of 10 % is
41、guaranteed:a) the microsection method specified in ISO 1463 for a thickness of 5 m (20 %) and above (local thickness);b) the dissolution method and chemical analysis for any thickness of gold alloy covering (average thickness) specified in ISO 27874;c) dissolution and measurement by the micrometer m
42、ethod specified in ISO 1463;d) the beta-ray backscatter method specified in ISO 3543;e) the X-ray spectrometric method (fluorescence) specified in ISO 3497;f) the coulometric method (coulometric method by anodic dissolution) specified in ISO 2177;g) the fizeau multiple-beam interferometry method spe
43、cified in ISO 3868;h) the scanning electron microscope method specified in ISO 9220;i) any other physical-chemical method which can guarantee accuracy.In the event of arbitration, the microsection method specified in ISO 1463 shall be used (local thickness).7 Determination of the corrosion resistanc
44、e7.1 Forms of corrosionThe various forms of corrosion which appear on a gold-alloy-covered article may be divided into three groups.a) Corrosion of the base metal at points where there are gaps in the covering: electrochemical cells may act at these points and accelerate penetration, and also at the
45、 boundary between the covering and the base metal.b) Attack caused by saline agents or possibly by mildly acidic agents (contact with perspiration, packaging, leathers or certain plastics): the products of corrosion may be of various colours, i.e. orange, violet, blue, green or brown.c) Attack cause
46、d by sulfur-containing agents (atmospheric hydrogen sulfide, vulcanized rubber, etc.): such agents may also attack the base metal at points where there are gaps in the protective covering. In addition, they cause changes in the surface colouring, which may even turn matt and black.The proposed tests
47、 make it possible for these various effects to be distinguished to a certain extent. Gold alloy coverings shall be resistant in all the environments described below. According to the nature of the article, the supplier may, with the agreement of the customer, determine the number of items to be subm
48、itted to each test.The development of corrosion is closely allied to the relative humidity of the ambient environment. ISO 2015 All rights reserved 3BS ISO 3160-2:2015ISO 3160-2:2015(E)7.2 Sampling and preparation7.2.1 GeneralAccording to the nature of the article, the supplier may, with the agreeme
49、nt of the customer, determine the number of items to be submitted to each test and the test conditions. The test conditions shall be stated in the test report.The tests for determination of the corrosion resistance are applicable to finished items in the condition in which they are supplied to customers. They can also be applied during manufacture, but any interpretation of results shall take into account the form which the item will take when in its final condition.7.2.2 Test of fini
