1、June 2011 Translation by DIN-Sprachendienst.English price group 8No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 25
2、.220.20!$s)h“1800669www.din.deDDIN EN ISO 8994Anodizing of aluminium and its alloys Rating system for the evaluation of pitting corrosion Grid method (ISO 8994:2011)English translation of DIN EN ISO 8994:2011-06Anodisieren von Aluminium und Aluminiumlegierungen Bewertungssystem fr Lochkorrosion Rast
3、erzhlmethode (ISO 8994:2011)Englische bersetzung von DIN EN ISO 8994:2011-06Anodisation de laluminium et de ses alliages Systme de cotation de la corrosion par piqres Mthode par quadrillage (ISO 8994:2011)Traduction anglaise de DIN EN ISO 8994:2011-06SupersedesDIN EN 12373-19:2001-10www.beuth.deDocu
4、ment comprises pagesIn case of doubt, the German-language original shall be considered authoritative.1106.11 DIN EN ISO 8994:2011-06 2 A comma is used as the decimal marker. National foreword This standard has been prepared by Technical Committee ISO/TC 79 “Light metals and their alloys”, Subcommitt
5、ee SC 2/WG 15 “Anodic oxidation coatings on aluminium” (Secretariat: JISC, Japan) in collaboration with Technical Committee CEN/TC 132 “Aluminium and aluminium alloys”, Working Group WG 15 “Aluminium anodisation” (Secretariat: BSI, United Kingdom). The responsible German body involved in its prepara
6、tion was the Normenausschuss Nichteisenmetalle (Nonferrous Metals Standards Committee), Working Committee NA 066-01-09 AA Anodisch oxidiertes Aluminium. Amendments This standard differs from DIN EN 12373-19:2001-10 as follows: a) the standard has been adopted as DIN EN ISO 8994:2011-06, and the main
7、 title has been modified (see National Annex NA); b) the standard has been editorially revised. Previous editions DIN EN 12373-19: 2001-10 DIN EN ISO 8994:2011-06 3 National Annex NA (informative) Correspondence between the previous standards series DIN EN 12373 “Aluminium and aluminium alloys Anodi
8、zing” and the corresponding new ISO and DIN EN ISO Standards Table NA.1 Correspondence previous now DIN EN 12373 DIN EN ISO Anodizing of aluminium and its alloys Part 1 7599 General specifications for anodic oxidation coatings on aluminium The title has been slightly changed Part 2 2106 Determinatio
9、n of mass per unit area (surface density) of anodic oxidation coatings Gravimetric method Part 3 2128 Determination of thickness of anodic oxidation coatings Non-destructive measurement by split-beam microscope Part 4 2143 Estimation of loss of absorptive power of anodic oxidation coatings after sea
10、ling Dye spot test with prior acid treatment Part 5 2931 Assessment of quality of sealed anodic oxidation coatings by measurement of admittance Part 6 Part 7 3210 Assessment of quality of sealed anodic oxidation coatings by measurement of the loss of mass after immersion in phosphoric acid/chromic a
11、cid solution The title has been changed: with/without prior acid treatment Part 8 6581 Determination of the comparative fastness to ultra-violet light and heat of coloured anodic oxidation coatings Part 9 Part 10 8251 Measurement of abrasion resistance of anodic oxidation coatings The title has been
12、 changed Part 11 7668 Measurement of specular reflectance and specular gloss of anodic oxidation coating at angles of 20 degrees, 45 degrees, 60 degrees or 85 degrees Part 12 6719 Measurement of reflectance characteristics of aluminium surfaces using integrating-sphere instruments Part 13 7759 Measu
13、rement of reflectance characteristics of aluminium surface using a goniophotometer or an abridged goniophotometer The German title has been slightly changed Part 14 10215 Visual determination of image clarity of anodic oxidation coatings Chart scale method Part 15 3211 Assessment of resistance of an
14、odic oxidation coatings to cracking by deformation Part 16 2085 Check for continuity of thin anodic oxidation coatings Copper sulphate test Part 17 2376 Determination of electric breakdown potential Part 18 8993 Rating system for the evaluation of pitting corrosion Chart method Part 19 8994 Rating s
15、ystem for the evaluation of pitting corrosion Grid method DIN EN ISO 8994:2011-06 4 This page is intentionally blank EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 8994 March 2011 ICS 77.060; 25.220.20 Supersedes EN 12373-19:2001English Version Anodizing of aluminium and its alloys - Ratin
16、g system for the evaluation of pitting corrosion - Grid method (ISO 8994:2011) Anodisation de laluminium et de ses alliages - Systme de cotation de la corrosion par piqres - Mthode par quadrillage (ISO 8994:2011) Anodisieren von Aluminium und Aluminiumlegierungen - Bewertungssystem fr Lochkorrosion
17、- Rasterzhlmethode (ISO 8994:2011) This European Standard was approved by CEN on 28 February 2011. 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-t
18、o-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC 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 transla
19、tion under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland,
20、 France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMIT
21、EE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 8994:2011: EContents DIN EN ISO 8994:2011-06 EN ISO 8994:2011 (E) 2 Page Foreword3 1 Scope 4 2 Terms and de
22、finitions .4 3 Procedure for rating 5 3.1 Sample preparation .5 3.2 Determination of grid rating .5 4 Expression of results 6 5 Test report 6 Bibliography 7 Foreword This document (EN ISO 8994:2011) has been prepared by Technical Committee ISO/TC 79 Light metals and their alloys” in collaboration wi
23、th Technical Committee CEN/TC 132 “Aluminium and aluminium alloys” the secretariat of which is held by AFNOR. 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 September 2011, and conflicting nation
24、al standards shall be withdrawn at the latest by September 2011. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document superse
25、des EN 12373-19:2001. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hun
26、gary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 8994:2011 has been approved by CEN as a EN ISO 8994:2011 without any modifica
27、tion. “ DIN EN ISO 8994:2011-06 EN ISO 8994:2011 (E) 3 1 Scope This International Standard specifies a grid rating system that provides a means of defining levels of performance of anodic oxidation coatings on aluminium and its alloys that have been subjected to corrosion tests. This rating system i
28、s applicable to pitting corrosion resulting from accelerated tests, exposure to corrosive environments, and practical service tests. This International Standard takes into account only pitting corrosion of the basis metal resulting from penetration of the protective anodic oxidation coating. NOTE 1
29、ISO 89933describes a similar rating system based on defined chart scales. NOTE 2 The grid rating system is frequently used for rating the results of short-term corrosion tests for relatively thin anodic oxidation coating, such as those used in the automotive industry. 2 Terms and definitions For the
30、 purposes of this document, the following terms and definitions apply. 2.1 significant surface part of the article covered or to be covered by the coating, for which the coating is essential for serviceability and/or appearance NOTE 1 Adapted from ISO 2064:19961, definition 3.1. NOTE 2 The edges of
31、an article are not normally included in the significant surface. 2.2 corrosion pit surface corrosion defect at which the anodic oxidation coating is penetrated NOTE Discoloration or other surface defects which do not penetrate the anodic coating do not count as corrosion pits. DIN EN ISO 8994:2011-0
32、6 EN ISO 8994:2011 (E) 4 3 Procedure for rating 3.1 Sample preparation A sample area of more than 5 000 mm2is required. Use one of the following methods to remove corrosion products or deposits on the surface so that corrosion pits may be clearly discerned: a) wipe with a slurry of fine pumice to ab
33、rade away corrosion products and dirt, then rinse in clean water and air dry; or b) dip for 5 min to 10 min in 30 % nitric acid, prepared by diluting 1 volume of concentrated nitric acid (20= 1,40 g/ml) with 1 volume of water at 20 C to 25 C; rinse and dry as indicated in a); or c) dissolve the anod
34、ic oxidation coating in a hot phosphoric acid/chromic acid mixture; rinse and dry as indicated in a) so that pitting in the aluminium substrate may be discerned; NOTE 1 ISO 21062describes the preparation and use of this reagent for the purposes of dissolution of the anodic oxidation coating. NOTE 2
35、This method is particularly useful for dark-coloured anodic oxidation coatings. WARNING Chromium(VI) is toxic and shall be handled properly. Chromium(VI) solutions are hazardous to the environment and severely hazardous to waters. or d) wipe with soft textile gauze dipped in dilute hydrochloric acid
36、 solution (100 ml of 35 % to 37 % HCl, made up to 1 000 ml with distilled water or deionized water) to remove deposited copper, then rinse and dry as indicated in a). 3.2 Determination of grid rating Place a preprinted transparent grid with an area of at least 5 000 mm2, and with grid squares of 5 m
37、m 5 mm, over a selected area of the significant surface of the prepared test specimen. Count the number of grid squares occupied by one or more pits, disregarding effects on the edges of samples. Calculate the percentage of defective squares, i.e. grid squares containing pits, using Formula (1): 100
38、tNN (1) where N is the number of defective squares; Ntis the total number of squares. Determine the grid rating from Table 1. DIN EN ISO 8994:2011-06 EN ISO 8994:2011 (E) 5 Table 1 Conversion of percentage of defective squares to grid rating Frequency of defective squares % Defective squares, N, of
39、200 squares, NtRating number 0 0 0 u0,5 1 1 0,5 to 1 2 2 1 to 2 3 or 4 3 2 to 4 5 to 8 6 4 to 8 9 to 16 12 8 to 16 17 to 32 25 16 to 32 33 to 64 50 32 to 64 65 to 128 100 64 128 200 NOTE The greater the number of squares, the more discriminating is the performance level. 4 Expression of results Expr
40、ess the result of the examination as the grid rating and/or the percentage of defective squares, as appropriate. 5 Test report The test report shall include at least the following information: a) a reference to this International Standard; b) the type and identification of the product tested and, wh
41、ere appropriate, the anodizing, exposure and corrosion test procedure; c) the method of sample preparation used (see 3.1); d) the grid rating and/or the percentage of defective squares (see Clause 4); NOTE The acceptable grid rating will normally be specified in the relevant corrosion test or produc
42、t specification. e) the date of the test. DIN EN ISO 8994:2011-06 EN ISO 8994:2011 (E) 6 Bibliography 1 ISO 2064:1996, Metallic and other inorganic coatings Definitions and conventions concerning the measurement of thickness 2 ISO 2106, Anodizing of aluminium and its alloys Determination of mass per unit area (surface density) of anodic oxidation coatings Gravimetric method 3 ISO 8993, Anodizing of aluminium and its alloys Rating system for the evaluation of pitting corrosion Chart method DIN EN ISO 8994:2011-06 EN ISO 8994:2011 (E) 7
