BS-ISO-27831-2-2008.pdf
BS ISO 27831-2:2008 ICS 25.220.20; 25.220.40 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BRITISH STANDARD Metallic and other inorganic coatings Cleaning and preparation of metal surfaces Part 2: Non-ferrous metals and alloys Licensed CopyChinese University of Hong Kong, 11/04/2009 08:53, Uncontrolled Copy, (c) BSI This British Standard was published under the authority of the Standards Policy and Strategy Committee on 28 February 2009 © BSI 2009 ISBN 978 0 580 60151 4 Amendments/corrigenda issued since publication DateComments BS ISO 27831-2:2008 National foreword This British Standard is the UK implementation of ISO 27831-2:2008. The UK participation in its preparation was entrusted to Technical Committee STI/33, Electrodeposited and related coatings. A list of organizations represented on this committee can be obtained on request to its secretary. 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 cannot confer immunity from legal obligations. Licensed CopyChinese University of Hong Kong, 11/04/2009 08:53, Uncontrolled Copy, (c) BSI BS ISO 27831-2:2008 Reference number ISO 27831-2:2008(E) © ISO 2008 INTERNATIONAL STANDARD ISO 27831-2 First edition 2008-10-15 Metallic and other inorganic coatings Cleaning and preparation of metal surfaces Part 2: Non-ferrous metals and alloys Revêtements métalliques et autres revêtements inorganiques Nettoyage et préparation des surfaces métalliques Partie 2: Métaux non ferreux et alliages Licensed CopyChinese University of Hong Kong, 11/04/2009 08:53, Uncontrolled Copy, (c) BSI BS ISO 27831-2:2008 ISO 27831-2:2008(E) PDF disclaimer This PDF file may contain embedded typefaces. 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ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii © ISO 2008 All rights reserved Licensed CopyChinese University of Hong Kong, 11/04/2009 08:53, Uncontrolled Copy, (c) BSI BS ISO 27831-2:2008 ISO 27831-2:2008(E) © ISO 2008 All rights reserved iii Contents Page Foreword. vii Introduction. viii 1 Scope . 1 2 Normative references. 2 3 Terms and definitions. 3 4 Essential information to be supplied by the purchaser to the processor 3 5 Requirements 4 6 Standard cleaning methods. 5 7 Non-corrosion-resisting steels, cast irons and pure irons 5 8 Corrosion-resisting and heat-resisting steels. 6 9 Pretreatment of metals prior to powder coating . 6 10 Cleaning and preparation processes 6 11 Aluminium and aluminium alloys 6 11.1 General. 6 11.2 General degreasing and cleaning. 6 11.3 Removal of corrosion products 6 11.4 Preparation prior to anodizing 7 11.5 Preparation prior to oxide removal treatment (process O) or filming treatment . 7 11.6 Preparation prior to adhesive bonding of unanodized items 7 11.7 Preparation prior to electroplating 7 11.8 Preparation prior to autocatalytic nickel plating. 7 11.9 Preparation prior to conversion coating 7 11.10 Preparation prior to metal spraying 7 11.11 Preparation prior to vitreous enamelling . 8 11.11.1 Sheet, extrusions and items made from casting alloys 8 11.11.2 Other castings. 8 11.12 Preparation prior to supplementary treatments on physically vapour deposited aluminium 8 12 Copper and copper alloys 8 12.1 General degreasing and cleaning. 8 12.2 Preparation prior to electroplating 9 12.3 Preparation prior to autocatalytic nickel plating. 9 12.4 Preparation prior to hot tinning (TRI process) 10 12.5 Preparation prior to vitreous tinning 10 13 Nickel alloys 10 13.1 General degreasing and cleaning. 10 13.2 Preparation prior to electroplating 10 13.3 Preparation prior to autocatalytic deposition 11 13.4 Preparation prior to vitreous enamelling . 11 14 Titanium and titanium alloys . 11 14.1 General degreasing and cleaning. 11 14.2 Preparation prior to electroplating 12 14.3 Preparation prior to autocatalytic nickel plating. 12 15 Magnesium alloys. 12 15.1 General degreasing and cleaning prior to electroplating and conversion coating. 12 Licensed CopyChinese University of Hong Kong, 11/04/2009 08:53, Uncontrolled Copy, (c) BSI BS ISO 27831-2:2008 ISO 27831-2:2008(E) iv © ISO 2008 All rights reserved 15.2 Preparation prior to electroplating12 15.3 Preparation prior to conversion coating 13 15.3.1 General.13 15.3.2 As-cast castings13 15.3.3 Machined castings14 15.3.4 Forgings.14 15.3.5 Sheets and extrusions14 16 Zinc-based alloys14 16.1 General degreasing and cleaning .14 16.2 Cleaning of corroded items14 16.3 Preparation of zinc alloy die castings prior to electroplating14 16.4 Preparation of zinc alloy castings prior to chromate conversion coating or phosphate treatment14 17 Tin and its alloys.14 18 Tungsten alloys.15 18.1 Preparation prior to electroplating15 18.2 Preparation prior to adhesive bonding.15 19 Lead and its alloys15 20 Zinc-, cadmium-, chromium- and gold-coated items.15 20.1 Preparation of zinc-coated items prior to chromate conversion coating .15 20.2 Preparation of cadmium-coated items prior to chromate conversion coating 15 20.3 Preparation of physically vapour deposited cadmium prior to supplementary treatments .15 20.4 Preparation for chromium-coated parts prior to supplementary treatments .16 20.5 Removal of surface contamination from gold coatings16 21 Pretreatment of metals prior to powder coating16 21.1 Preparation of aluminium prior to powder coating .16 21.2 Preparation of zinc and hot-dip-galvanized steel prior to powder coating.16 21.3 Preparation of copper and brass prior to powder coating .16 22 Cleaning and preparation processes16 22.1 Process A Organic-solvent degreasing and cleaning17 22.1.1 General.17 22.1.2 Method A1 Hot solvent, not water-rinsable .17 22.1.3 Method A2 Cold solvent, not water-rinsable .17 22.1.4 Method A3 Hot solvent, water-rinsable 17 22.1.5 Method A4 Cold solvent, water-rinsable18 22.1.6 Method A5 Petroleum fuel based mixtures containing emulsifying agents 18 22.1.7 Method A6 Ultrasonic cleaning.18 22.2 Process B Alkaline degreasing.18 22.2.1 General.18 22.2.2 Method B1 General-purpose alkaline degreasing.18 22.2.3 Method B2 Mild alkaline degreasing 18 22.2.4 Method B3 Cathodic alkaline degreasing19 22.3 Process C Acid emulsion cleaning.19 22.4 Process D Abrasive cleaning19 22.4.1 General.19 22.4.2 Method D1 Coarse-abrasive blasting . 19 22.4.3 Method D2 Fine-abrasive blasting19 22.4.4 Method D3 Scouring.19 22.4.5 Method D4 Tumbling20 22.4.6 Method D5 Wire brushing20 22.5 Process E Caustic-alkali descaling 20 22.6 Process F Acid pickling without electrolysis20 22.7 Process G Acid dipping.20 22.8 Process H Anodic pickling20 22.8.1 General.20 22.8.2 Method H120 Licensed CopyChinese University of Hong Kong, 11/04/2009 08:53, Uncontrolled Copy, (c) BSI BS ISO 27831-2:2008 ISO 27831-2:2008(E) © ISO 2008 All rights reserved v 22.9 Process J Acid de-rusting. 20 22.10 Process K Alkaline de-rusting 21 22.11 Process L Chemical smoothing and electropolishing of steels . 21 22.12 Process M Passivation and removal of surface contamination from corrosion-resisting steels and surface preparation prior to electroplating. 21 22.13 Process N Acid pickling of aluminium alloys . 21 22.13.1 General. 21 22.13.2 Method N1 21 22.13.3 Method N2 21 22.13.4 Method N3 21 22.13.5 Method N4 22 22.13.6 Method N5 22 22.13.7 Method N6 22 22.14 Process O Oxide removal, i.e. “etching”, treatment of aluminium and aluminium alloys. 22 22.14.1 General. 22 22.14.2 Degreasing and cleaning . 22 22.14.3 Preparation prior to anodizing and adhesive bonding. 23 22.15 Process P Aluminium and aluminium alloys Removal of corrosion products, etching treatment, chemical polishing, electrobrightening and electropolishing. 24 22.15.1 Removal of corrosion products 24 22.15.1.1 Method P1 Immersion 24 22.15.1.2 Method P2 Swabbing . 24 22.15.2 Etching treatment . 24 22.15.2.1 Method P3 Etching by brushing or spray treatment. 24 22.15.2.2 Method P4 Etching and de-smutting treatment using sodium hydroxide 24 22.15.3 Method P5 Chemical polishing. 25 22.15.4 Method P6 Electrobrightening 25 22.15.5 Method P7 Electropolishing 26 22.16 Process Q Cleaning of copper and copper alloys 26 22.16.1 Method Q1 Cleaning in dichromate/sulfuric acid solution 26 22.16.2 Method Q2 Cleaning in ferric sulfate/sulfuric acid solution 26 22.17 Process R Acid descaling, etching, chemical smoothing and electropolishing of copper and copper alloys 26 22.17.1 Method R1 Descaling dip 26 22.17.2 Method R2 Bright dip. 26 22.17.3 Method R3 Chemical smoothing 27 22.17.4 Method R4 Pickling in nitric acid 27 22.17.5 Method R5 Electropolishing 27 22.18 Process S Pickling of titanium and titanium alloys 27 22.18.1 General. 27 22.18.2 Method S1 27 22.18.3 Method S2 27 22.19 Process T Pickling, chemical polishing and electropolishing of nickel and its alloys. 28 22.19.1 General. 28 22.19.2 Method T1 28 22.19.3 Method T2 28 22.19.4 Method T3 28 22.19.5 Method T4 Chemical polishing. 28 22.19.6 Method T5 Electropolishing 29 22.20 Process U Preparation of tin alloy for electroplating. 29 22.21 Process V Removal of surface contamination from gold coatings 29 22.22 Process W Preparation of aluminium alloys prior to electroplating. 29 22.23 Process X Preparation of nickel alloys prior to electroplating . 30 22.24 Process Y Preparation of titanium alloys prior to electroplating 31 22.24.1 Method Y1 General method for titanium alloys 31 22.24.2 Method Y2 Method for titanium and selected titanium alloys. 32 22.24.3 Method Y3 Chemical-etching method 32 22.25 Process Z Preparation of zinc and zinc alloys prior to electroplating . 33 22.25.1 Method Z1 33 22.25.2 Method Z2 33 Licensed CopyChinese University of Hong Kong, 11/04/2009 08:53, Uncontrolled Copy, (c) BSI BS ISO 27831-2:2008 ISO 27831-2:2008(E) vi © ISO 2008 All rights reserved Annex A (informative) Maintenance of organic and vapour degreasing baths34 Annex B (informative) The control of acidity in vapour cleaning baths .35 Annex C (normative) Method for the determination of oxidizable material in sulfuric acid.36 Annex D (informative) Method for determining free acidity.37 Annex E (normative) Selection of method of cleaning according to the tensile strength of the steel in zinc-coated steel items prior to chromate conversion coating38 Annex F (normative) Method M4.40 Bibliography .41 Licensed CopyChinese University of Hong Kong, 11/04/2009 08:53, Uncontrolled Copy, (c) BSI BS ISO 27831-2:2008 ISO 27831-2:2008(E) © ISO 2008 All rights reserved vii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards 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 organizations, 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. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. 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. ISO 27831-2 was prepared by Technical Committee ISO/TC 107, Metallic and other inorganic coatings, Subcommittee SC 3, Electrodeposited coatings and related finishes. ISO 27831 consists of the following parts, under the general title Metallic and other inorganic coatings Cleaning and preparation of metal surfaces: Part 1: Ferrous metals and alloys Part 2: Non-ferrous metals and alloys Licensed CopyChinese University of Hong Kong, 11/04/2009 08:53, Uncontrolled Copy, (c) BSI BS ISO 27831-2:2008 ISO 27831-2:2008(E) viii © ISO 2008 All rights reserved Introduction The adhesion of deposited coatings depends upon the efficiency of degreasing and cleaning processes used on the substrate surface. The removal of grease, oil and dirt and all other forms of contamination left from fabrication processes or due to corrosion/erosion of surfaces in storage or in service is essential for successful production of a pristine, chemically clean active surface for deposition of coatings. The surface contaminants can be corrosion products, mould sand or mould release agents on ferrous and non-ferrous castings; corrosion products and mill scales on hot-rolled steel sheet, girders, etc. (broken mill scale is cathodic to the underlying substrate); oil and rolling lubricant on cold-rolled steel sheet; rolling lubricant on e.g. cold-rolled aluminium sheet; corrosion products on delivery or during storage on hot-dip-galvanized steel sheet or angle bars/brackets; other undesirable materials from storage and handling. The difficulty of coating these surfaces is well known. Cleaning processes for removing surface contaminants are varied, depending, among other things, on the identification and classification of the soil as well as the size and shape of the substrate, the degree of cleanliness required, the availability of the facil
