DIN 50958-2012 Electroplated coatings - Modified corrodkote corrosion test (mod CORR-Test)《电镀层 按改良的柯洛特考得(corrodkote)腐蚀试验(mod CORR-Test)》.pdf

1、December 2012 Translation by DIN-Sprachendienst.English price group 6No 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).IC

2、S 25.220.40; 77.060!%+s“2089480www.din.deDDIN 50958Electroplated coatings Modified corrodkote corrosion test (mod. CORR-Test),English translation of DIN 50958:2012-12Galvanische berzge Modifizierte Corrodkote-Korrosionsprfung (mod. CORR-Test),Englische bersetzung von DIN 50958:2012-12Dpts lectrolyti

3、ques Essai de corrosion suite la mthode modifie de corrodkote (mod. CORR-Test),Traduction anglaise de DIN 50958:2012-12SupersedesDIN 50958:2001-07www.beuth.deDocument comprises 7 pagesIn case of doubt, the German-language original shall be considered authoritative.02.14 DIN 50958:2012-12 2 A comma i

4、s used as the decimal marker. Contents Page Foreword . 3 1 Scope . 5 2 Normative references . 5 3 Principle . 5 4 Samples . 5 5 Apparatus 5 6 Slurry preparation and reagents . 6 7 Procedure 6 7.1 Cleaning of samples before applying the slurry . 6 7.2 Application of slurry . 6 7.3 Conditioning of sam

5、ples in the controlled-atmosphere test chamber . 6 7.4 Test climate . 6 7.5 Test cycle . 6 7.6 Repeated conditioning of the samples in the controlled-atmosphere test chamber 6 8 Evaluation 7 9 Test report . 7 DIN 50958:2012-12 3 Foreword This standard has been prepared by Working Committee NA 062-01

6、-61 AA Mess- und Prfverfahren fr metallische und andere anorganische berzge of the Normenausschuss Materialprfung (NMP) (Materials Testing Standards Committee). Attention is drawn to the possibility that some of the elements of this document may be subject of patent rights. DIN and/or DKE shall not

7、be held responsible for identifying any or all such patent rights. This revised edition of DIN 50958 uses, instead of the corrodkote method as described in DIN EN ISO 4541, the modified corrodkote method that is based on AST M B 380-65 and is generally used in Germany. The modified corrodkote method

8、 mainly differs from the method specified in DIN EN ISO 4541 as follows: a) A temperature of (40 3) C and a relative humidity of 100 % have been specified instead of (38 1) C and a relative humidity of 80 % to 90 %, respectively. These conditions are easier to maintain and are those generally used i

9、n German practice. b) The provision that the slurry is to be dried at a relative humidity below 50 % has not been included. Experience has shown that this deviation does not affect the results of the modified test. c) The thickness of the wet slurry layer has been reduced to approximately 50 m. DIN

10、EN ISO 4541 specifies a thickness of the wet slurry between 80 m and 200 m. d) Unless otherwise agreed, the samples shall be conditioned in the humidity chamber for 16 h without interruption. DIN EN ISO 4541 specifies a conditioning period of up to 16 h, with a short interruption for loading and unl

11、oading new samples into the humidity chamber being permitted. e) After the test the corrosion sites are made visible by conditioning the samples for 24 h in a DIN EN ISO 6270-2 CH-type atmosphere or exposure for 4 h in the neutral salt spray test (NSS) as specified in DIN EN ISO 9227. DIN EN ISO 454

12、1, however, specifies a conditioning period of 4 h in a neutral salt spray test as in ISO 3768 or conditioning in a humidity chamber for 24 h at 38 C and 100 % relative humidity, in order to render the corrosion sites visible. NOTE ISO 3768 has been withdrawn and been replaced by ISO 9227 of which t

13、he German version is DIN EN ISO 9227. DIN 50958:2012-12 4 Amendments This standard differs from DIN 50958:2001-07 as follows: a) as an alternative to storage in a constant condensation-water atmosphere, brief exposure to the neutral salt spray test is now permitted in order to render the corrosion s

14、ites visible (Clause 8); b) normative references have been updated; c) the standard has been editorially revised. Previous editions DIN 50958: 1970-02, 1979-05, 2001-07 DIN 50958:2012-12 5 1 Scope This standard specifies a method to test corrosion resistance, especially that of products made of alum

15、inium materials and nickel/chromium-coated or copper/nickel/chromium-coated steel, of copper/nickel/chromium-coated zinc die castings and of products made of copper or nickel/chromium-coated copper materials. 2 Normative references The following documents are indispensable for the application of thi

16、s document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. DIN EN ISO 4541:1995-01, Metallic and other non-organic coatings Corrodkote corrosion test (CORR test) (ISO 4541:1978) DIN EN IS

17、O 6270-2, Paints and varnishes Determination of resistance to humidity Part 2: Procedure for exposing test specimens in condensation-water atmospheres DIN EN ISO 6988, Metallic and other non-organic coatings Sulfur dioxide test with general condensation of moisture DIN EN ISO 9227, Corrosion tests i

18、n artificial atmospheres Salt spray tests DIN EN ISO 10289, Methods for corrosion testing of metallic and other inorganic coatings on metallic substrates Rating of test specimens and manufactured articles subjected to corrosion tests 3 Principle After being coated with a corrosive slurry of specifie

19、d composition (referred to below as “slurry”), the sample is exposed to a hot and humid climate for a specified time. After this conditioning period, the corrosion-protective effect of the electrodeposited coating is then assessed on the basis of the number and size of those sites at which the paren

20、t metal has been corroded. 4 Samples The samples used shall generally be finished parts. Their number, or the use of other samples and the criteria used to assess the results shall be subject to agreement. 5 Apparatus Controlled-atmosphere test chamber, such as that described in DIN EN ISO 6270-2 an

21、d DIN EN ISO 6988, capable of being maintained at a temperature of (40 3) C and a relative humidity of 100 % (i.e. producing a DIN EN ISO 6270-2 CH-type atmosphere). The chamber shall be designed to prevent condensation water from dripping on the samples. If the equipment has previously been used fo

22、r a test involving a sulfur dioxide atmosphere, clean it for at least five days using a DIN EN ISO 6270-2 CH-type atmosphere, renewing the water daily. The chamber shall include a sample rack made of a corrosion-resistant material or a material having a corrosion-resistant coating. The rack shall ha

23、ve transverse rods and suspension devices made of an electrically non-conductive material (e.g. glass) to prevent galvanic corrosion. The materials and coatings of the rack and of the internal walls of the chamber shall not release any substances likely to promote or retard the corrosion of the samp

24、les. DIN 50958:2012-12 6 6 Slurry preparation and reagents The slurry preparation and the reagents used shall be as specified in DIN EN ISO 4541. 7 Procedure 7.1 Cleaning of samples before applying the slurry As specified in DIN EN ISO 4541:1995-01, 6.2. 7.2 Application of slurry Apply the slurry to

25、 the samples with a clean, soft brush, first covering them completely with a circular motion and then distributing the slurry uniformly by lightly brushing in one direction so that the wet layer is about 50 m thick. The samples shall be tested as specified in DIN EN ISO 4541:1995-01, 6.4. Before pla

26、cing the samples in the chamber, allow the slurry to dry for 1 h at ambient temperature in dry air free of aggressive gases, vapours and metallic dust. 7.3 Conditioning of samples in the controlled-atmosphere test chamber As specified in DIN EN ISO 4541. 7.4 Test climate Maintain a temperature of (4

27、0 3) C and a relative humidity of 100 % (i.e. DIN EN ISO 6270-2 CH-type atmosphere) in the chamber. 7.5 Test cycle A single storage of the samples with fresh slurry in the chamber represents one test cycle. Unless otherwise agreed, samples coated with fresh slurry shall be conditioned in the chamber

28、 for a period of 16 h, during which time the chamber shall not be opened. 7.6 Repeated conditioning of the samples in the controlled-atmosphere test chamber If more than one test cycle has been agreed upon, remove the slurry completely from the samples at the end of every cycle using cold running wa

29、ter and a soft cloth or soft sponge immediately after removal from the chamber. Adhering substances can be removed with a mild abrasive (e.g. suspended Vienna lime). After the samples have been dried, repeat the treatment described in 7.2 to 7.6 for the agreed number of test cycles. NOTE Vienna lime

30、 is a burnt, finely ground dolomite. DIN 50958:2012-12 7 8 Evaluation Immediately after the treatment described in Clause 7, examine the samples for corrosion. The evaluation method shall be by agreement, unless DIN EN ISO 10289 is being employed. In the case of decoratively chromium-plated steel sa

31、mples, the corrosion products stain the slurry above the corrosion sites a reddish brown; therefore, they can be detected without removing the slurry. However, this is not the case for decoratively chromium-plated aluminium and copper material or zinc die castings. NOTE Even where the tests are carr

32、ied out with utmost care, a red colouring of the slurry may occur due to contamination from ferrous samples if these have been tested in the laboratory. For a reliable evaluation of the samples the slurry should be removed as described in 7.6 and the corrosion sites made visible as described in the

33、following paragraph. For a quantitative evaluation, remove the slurry by washing as described in 7.6. This will also remove the corrosion products. To render the corrosion sites clearly visible, the sample can be subjected to further exposure (as a rule, by conditioning the samples in a DIN EN ISO 6

34、270-2 CH-type atmosphere for a further 24 h). The parent material will once again corrode. Alternatively, the samples can be exposed to the neutral salt spray test (NSS) as specified in DIN EN ISO 9227 for 4 h. 9 Test report The report shall include the following information as a minimum: a) a refer

35、ence to this standard (i.e. DIN 50958); b) type of workpiece tested; c) type of sampling; d) number of samples; e) test equipment used; f) time of exposure in test chamber (duration of one test cycle); g) number of test cycles; h) method of detecting sites at which corrosion of the parent metal has occurred; i) evaluation method used; j) result of evaluation; k) any deviation from this standard; l) date of testing.