1、Designation: D870 15Standard Practice forTesting Water Resistance of Coatings Using WaterImmersion1This standard is issued under the fixed designation D870; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、 A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This practice covers the basic principles and operatingprocedures for testing water resistance of coatings by thepartial or complet
3、e immersion of coated specimens in distilledor de-mineralized water at ambient or elevated temperatures.Although the apparatus and procedure could be employed inimmersion tests using solutions of various materials in water,this practice is limited to tests in water alone.1.2 This practice is limited
4、 to the methods of obtaining,measuring, and controlling the conditions and procedures ofwater immersion tests. It does not specify specimenpreparation, specific test conditions, or evaluation of results.NOTE 1Alternative practices for testing the water resistance ofcoatings include Practices D1735,
5、D2247, and D4585.1.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard
6、 to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D609 Practice for Preparation of Cold-Rolled Steel Panelsfor Testing Paint, Varnish, Conversion Coatings, andRelated Coating Produ
7、ctsD610 Practice for Evaluating Degree of Rusting on PaintedSteel SurfacesD714 Test Method for Evaluating Degree of Blistering ofPaintsD823 Practices for Producing Films of Uniform Thicknessof Paint, Varnish, and Related Products on Test PanelsD1193 Specification for Reagent WaterD1654 Test Method f
8、or Evaluation of Painted or CoatedSpecimens Subjected to Corrosive EnvironmentsD1730 Practices for Preparation of Aluminum andAluminum-Alloy Surfaces for PaintingD1735 Practice for Testing Water Resistance of CoatingsUsing Water Fog ApparatusD2247 Practice for Testing Water Resistance of Coatings in
9、100 % Relative HumidityD2616 Test Method for Evaluation of Visual Color Differ-ence With a Gray ScaleD3359 Test Methods for Measuring Adhesion by Tape TestD3363 Test Method for Film Hardness by Pencil TestD4541 Test Method for Pull-Off Strength of Coatings UsingPortable Adhesion TestersD4585 Practic
10、e for Testing Water Resistance of CoatingsUsing Controlled Condensation3. Summary of Practice3.1 Coated specimens are partially or wholly immersed inwater in a container that is resistant to corrosion. The exposureconditions are varied by selecting: (a) the temperature of thewater, and (b) the durat
11、ion of the test. Water permeates thecoating at rates that are dependent upon the characteristics ofthe coating and upon the temperature of the water. Any effectssuch as color change, blistering, loss of adhesion, softening, orembrittlement are observed and reported.4. Significance and Use4.1 Immersi
12、on in water can cause the degradation of coat-ings. Knowledge on how a coating resists water immersion ishelpful in predicting its service life. Failure in a waterimmersion test may be caused by a number of factors includinga deficiency in the coating itself, contamination of thesubstrate, or inadeq
13、uate surface preparation. The test is there-fore useful for evaluating coatings alone or complete coatingsystems.4.2 Water immersion tests are used for research and devel-opment of coatings and substrate treatments, specificationacceptance, and quality control in manufacturing. These tests1This prac
14、tice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.27 on Accelerated Testing.Current edition approved Feb. 1, 2015. Published March 2015. Originallyapproved in 1946. Last previous edition
15、approved in 2009 as D870 09. DOI:10.1520/D0870-15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.*A Summary
16、of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1typically result in a pass or fail determination, but the degree offailure may also be measured. A coating system is consideredto pa
17、ss if there is no evidence of water-related failure after aspecified period of time.4.3 Results obtained from water immersion tests in accor-dance with this practice should not be represented as beingequivalent to a period of exposure to water in the naturalenvironment, until the degree of quantitat
18、ive correlation hasbeen established for the coating or coating system.4.4 Corrosion tests of a scribed coating on a ferrous sub-strate are impractical in water immersion tests as the corrosionproducts tend to contaminate the water bath. Continuousoverflow of the test tank is sometimes required to ma
19、intainconsistent water quality.4.5 The apparatus for the test is relatively inexpensive andcan be as simple as a glass beaker with a stirrer. It is alsopossible to use very large tanks for testing coated pipe or otherlarge coated products.5. Apparatus5.1 Tank Cover, required for some test specificat
20、ions. Thecover is not to touch the test specimens. The reason for thecover is to help maintain water temperature and water level.5.2 Gabled Cover for TankThe cover should be made ofcorrosion-resistant materials. The cover should not touch anyof the test specimens nor interfere with the air circulati
21、onaround the specimens.5.3 System, for circulation of the water with pressurized air,a stirrer, or a pump.5.4 Supports for the Test Specimens, constructed of non-conductive materials to hold the specimens 30 mm apart and 30mm from the bottom and sidewalls of the tank.NOTE 2The circulating system is
22、for the purpose of exposing all thewater in the tank to room air so the water does not become stratified andoxygen-depleted at the lower levels.6. Test Specimens6.1 This practice does not cover the preparation of testspecimens. The substrate composition and surface preparation,specimen preparation,
23、and the number of specimens should beagreed upon prior to testing.NOTE 3Applicable methods for the preparation of test panels andsubstrates are given in Practices D609 and D1730. Practices D823 coversapplication techniques for the production of uniform films.6.2 It is recommended that a control spec
24、imen of a paintwith known durability be included with each test. Such controlspecimens can provide warning of changes in test severity in agiven apparatus, and can indicate variations in test severitybetween different apparatuses.6.3 It is recommended that at least two replicate specimensof each dif
25、ferent coating be used, to compensate for variationsbetween specimens and variations in test conditions within theapparatus.7. Procedure7.1 Fill the tank with water to a depth such that the testspecimens are immersed for approximately three-quarters oftheir length. Reagent water conforming to Type I
26、V of Speci-fication D1193 is suitable for use.7.2 Heat the water to the desired temperature with thecirculating system in operation. If no temperature is specified,heat the water to 38 6 2C (100 6 4F). Maintain thetemperature throughout the test.7.2.1 Other temperatures that are commonly used are 32
27、C(90F) and 40C (104F).7.2.2 During equilibrium conditions, the maximum allow-able deviation from the desired water temperature indicated bythe device or display measuring water temperature is 62C(64F). If the display shows a water temperature outside theselimits, stop the test and correct the proble
28、m before proceeding.7.2.3 For some tests where increased oxygen content of thewater is desired to accelerate failure, air may be bubbledthrough the water. When air is bubbled through the water, theminimum rate for introduction of air shall be one bubble persecond through a 6 mm hose made of a materi
29、al that does notcontaminate the DI water.7.3 Place the test specimens in the tank so that the plane ofthe specimens is parallel to the flow of water in the tank.Protect the edges and backs of the specimens from corrosion ifthese surfaces are not to be tested.7.3.1 To control for variability within t
30、he apparatus, repo-sition the specimens on a regular basis so that all specimensspend equivalent amounts of time in the various areas of theapparatus (front, back, left, right, and center).7.4 Replace the water if it becomes cloudy or colored.Continuous replacement of the water is permitted. If need
31、ed ,add water to maintain original water level.7.4.1 Measure water conductivity once per week. Replacethe water if conductivity is greater than 20 S/cm at 20C(resistivity less than 50 k/cm).Alternatively change the wateronce per week without measuring conductivity.7.5 Conclude the test after a speci
32、fied period of time, orafter effects from water immersion have been observed.7.6 Wipe the test specimens dry. Rate specimens forchanges in color, blistering, etc. Evaluate specimens no lessthan 5 min and no more than 10 min after removal from test,as the effects from water exposure can change within
33、 a shorttime. Remove only as many specimens as can be rated withinthe specified time.NOTE 4The 0 to 10 scale described in ASTM STP 5003is preferredfor rating. Relevant procedures for evaluating water effects are describedin Test Methods D610, D714, D1654, D2616, D3359, D3363, and D4541.7.6.1 If poss
34、ible, rate the specimens again after they havebeen removed from the test for a recovery period long enoughthat moisture absorbed within the specimens dries out and thespecimens reach moisture equilibrium with room air. A recov-ery period from 12 to 24 h is generally sufficient. Thepost-recovery rati
35、ng allows evaluation of the permanent effectsof the exposure as distinct from the transient effects, and isespecially important for evaluation of color and gloss.3Paint and Coating Testing Manual, 14th ed., ASTM, 1995.D870 1528. Report8.1 Report the following information:8.1.1 Sample identification.
36、8.1.2 Results of the evaluation(s).8.1.3 Reference to Practice D870.8.1.4 Hours of test duration.8.1.5 Test temperature.8.1.6 Brief description of water quality and water replace-ment procedure.8.1.7 Special conditions of test or any deviations in testprocedure.9. Keywords9.1 adhesion; blistering; i
37、mmersion; resistance-water; rustSUMMARY OF CHANGESCommittee D01 has identified the location of selected changes to this standard since the last issue (D87009)that may impact the use of this standard. (Approved February 1, 2015.)(1) Replaced 32.2C in section 7.2.1 with 32C.ASTM International takes no
38、 position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own respons
39、ibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed t
40、o ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the add
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