1、Designation: D6943 10Standard Practice forImmersion Testing of Industrial Protective Coatings1This standard is issued under the fixed designation D6943; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A n
2、umber in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice establishes procedures for the evaluationof the resistance of industrial protective coatings to immersionin chemicals.1.2
3、The values stated in SI units are to be regarded as thestandard. The values given in parenthesis are for informationonly.1.3 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 to establish appro-p
4、riate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C868 Test Method for Chemical Resistance of ProtectiveLiningsD16 Terminology for Paint, Related Coatings, Materials,and ApplicationsD610 Practice for E
5、valuating Degree of Rusting on PaintedSteel SurfacesD714 Test Method for Evaluating Degree of Blistering ofPaintsD2200 Practice for Use of Pictorial Surface PreparationStandards and Guides for Painting Steel SurfacesD3359 Test Methods for Measuring Adhesion by Tape TestD3363 Test Method for Film Har
6、dness by Pencil TestD4138 Practices for Measurement of Dry Film Thickness ofProtective Coating Systems by Destructive, Cross-Sectioning MeansD4417 Test Methods for Field Measurement of SurfaceProfile of Blast Cleaned SteelD4538 Terminology Relating to Protective Coating andLining Work for Power Gene
7、ration FacilitiesD4541 Test Method for Pull-Off Strength of Coatings UsingPortable Adhesion TestersD5139 Specification for Sample Preparation for Qualifica-tion Testing of Coatings to be Used in Nuclear PowerPlants3D5162 Practice for Discontinuity (Holiday) Testing of Non-conductive Protective Coati
8、ng on Metallic SubstratesD6132 Test Method for Nondestructive Measurement ofDry Film Thickness ofApplied Organic Coatings Using anUltrasonic GageD6577 Guide for Testing Industrial Protective CoatingsD6677 Test Method for Evaluating Adhesion by KnifeD7055 Practice for Preparation (by Abrasive Blast C
9、lean-ing) of Hot-Rolled Carbon Steel Panels for Testing ofCoatingsD7091 Practice for Nondestructive Measurement of DryFilm Thickness of Nonmagnetic Coatings Applied toFerrous Metals and Nonmagnetic, Nonconductive Coat-ings Applied to Non-Ferrous MetalsD7234 Test Method for Pull-Off Adhesion Strength
10、 ofCoatings on Concrete Using Portable Pull-Off AdhesionTestersG113 Terminology Relating to Natural andArtificial Weath-ering Tests of Nonmetallic Materials2.2 NACE Standard:4TM 0174-2002 Laboratory Methods for the Evaluation ofProtective Coatings and Lining Materials on MetallicSubstrates in Immers
11、ion Service2.3 SSPC/NACE Joint Standards:5SSPC-SP5/NACE 1 White Metal Blast CleaningSSPC-SP10/NACE 2 Near White Blast CleaningSSPC-SP13/NACE 6 Surface Preparation of Concrete2.4 SSPC Protective Coatings Glossary52.5 Coating Encyclopedia Dictionary63. Terminology3.1 The definitions given in Terminolo
12、gies D16, G113 andD4538 are applicable to this practice.1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.46 on Industrial Protective Coatings.Current edition approved Feb. 1, 2
13、010. Published March 2010. Originallyapproved in 2003. Last previous edition approved in 2003 as D6943 - 03. DOI:10.1520/D6943-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume informat
14、ion, refer to the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.4Available from NACE International (NACE), 1440 South Creek Dr., Houston,TX 77084-4906, http:/www.nace.org.5Available from Society for P
15、rotective Coatings (SSPC), 40 24th St., 6th Floor,Pittsburgh, PA 15222-4656, http:/www.sspc.org.6Available from Federation of Societies for Coatings Technology (FSCT), 492Norristown Rd., Blue Bell, PA 19422-2350, http:/www.coatingstech.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box
16、 C700, West Conshohocken, PA 19428-2959, United States.4. Significance and Use4.1 Protective coatings are used on metallic and concretestorage and processing vessels, shipping containers, dams andrail cars to protect the substrate from corrosive attack and toprotect stored materials (cargo) from con
17、tamination. Thismethod provides a means to assess the ability of a protectivecoating to resist degradation by chemicals and to protect theliquid cargo from contamination by either the substrate orcoating, based on visual observations. Other measures ofdegradation, such as changes in weight or dimens
18、ions of thecoating material, or chemical changes to the cargo, may beused to assess this protective ability as mutually agreed uponbetween contracting parties.4.2 This standard practice covers three approaches to con-ducting evaluations of a lining coating materials fitness forpurpose.4.2.1 Method A
19、Evaluation of specimens under conditionsof constant temperature at atmospheric pressure, (that is,without a thermal gradient).4.2.2 Method BEvaluation of specimens under conditionswhich provides a temperature gradient across the sample: Thetemperature may increase from coated side to uncoated side(M
20、ethod B1) or decrease from coated side to uncoated side(Method B2).4.2.3 Method CEvaluation of specimens under conditionsof constant temperature and increased pressure, (that is, with-out a thermal gradient).4.3 Exposure of materials of known performance (a control)at the same time as the test mater
21、ial is recommended.5. Preparation of Test Specimens5.1 Metallic Panels:5.1.1 Use carbon steel panels with a minimum test size of 50by 100 mm (2 by 4 in.), minimum thickness 3 mm (18 in.),unless otherwise agreed upon by purchaser and supplier.NOTE 1Test plates with a minimum width of 25 mm (1 in.) ma
22、y beused if the film thickness is sufficiently uniform to prevent edge effects.5.1.2 Use nominal 4.8 mm (316 in.) thick carbon steel panelsin coating tests if a temperature gradient is included in theimmersion test, unless otherwise agreed upon by purchaser andsupplier.5.1.3 The minimum surface prep
23、aration is abrasive blastcleaning to Near-White Metal condition as defined by PracticeD2200 and by SSPC-SP10/NACE 2. The abrasive and feedpressure shall be selected to produce an anchor pattern, whichis compatible with the coating system and acceptable to thecoating manufacturer.5.1.4 Unless otherwi
24、se specified or agreed upon by pur-chaser and seller, surface preparation shall be “White MetalBlast Cleaning” according to SSPC-SP5/NACE 1, with surfaceprofile of 35 to 90 micrometers (1.5 to 3.5 mils) as determinedby Method C of Test Methods D4417. If the product recom-mendation falls outside of t
25、he range of Test Methods D4417then prepare the test panels in accordance with Practice D7055.5.1.5 Other metallic substrates, panel dimensions, or surfacepreparation are acceptable if agreeable to concerned parties.5.2 Concrete and Cementitious Panels:5.2.1 Cementitious PanelsThe minimum panel size
26、is 50by 100 by 12 mm (2 by 4 by12 in.). Prepare cementitiouspanels by abrasive blast cleaning in accordance with SSPC-SP13/NACE 6 or by other method agreed upon betweenpurchaser and supplier.5.2.2 Concrete BlocksForm, condition and prepare con-crete blocks in accordance with the protocol described i
27、nSpecification D5139. Prepare concrete blocks by abrasive blastcleaning in accordance with SSPC-SP13/NACE 6 or by othermethod agreed upon between purchaser and supplier.5.3 Coating Application:5.3.1 For panels to be fully immersed, apply the coatingsystem to all test panel surfaces that will be subj
28、ected toexposure.5.3.2 Apply the coating system according to the manufac-turers instructions appropriate for actual or anticipated serviceconditions. Edges should be protected unless the intent of theexperiment is to evaluate the performance of the coating onedges. For coatings to be tested under Me
29、thod A (immersionwith no temperature gradient) or Method C (immersion at highpressure), apply the candidate coating to the back of the panelin addition to the front and the edges to prevent effects fromdissimilar coatings.5.3.3 Dry film thickness of the coating shall be agreed uponbetween purchaser
30、and seller.5.3.3.1 Measure dry film thickness of coating applied tometal surfaces in accordance with Practice D7091.5.3.3.2 Measure dry film thickness of linings applied toconcrete or cementitious surfaces in accordance with TestMethod D6132. Alternatively, measure dry film thickness oflinings appli
31、ed to concrete or cementitious surfaces by usingsacrificial surfaces prepared concurrently with test specimensin accordance with Practices D4138.5.3.4 Examine the coated surface for holidays in accordancewith Practice D5162. For test plates and concrete blocks, noholidays are acceptable unless agree
32、d upon between purchaserand seller.6. Sampling6.1 Test chemicals are to be representative of test materialsexpected in actual service.6.2 Prepare at least two test panels or blocks per coatingsystem for each test material.6.3 Prepare at least one test panel or block per coatingsystem to be used as a
33、n unexposed reference (file specimen).6.4 Retain an unused portion of each test medium as ablank.7. Test MethodsNOTE 2This standard describes three methods for immersion testingof protective coatings and linings. Section 8 provides recommendedexamination methods and intervals between evaluations for
34、 the methodsdescribed below.7.1 Method AImmersion with No Temperature Gradient:7.1.1 Test Apparatus:7.1.1.1 A closed vessel constructed of glass or other inertmaterial is used with capacity to hold one or more testspecimens with means to relieve pressure if operated atelevated temperatures.D6943 102
35、NOTE 3Slowly evaporating media may not require a closed vessel.7.1.1.2 Specimens should be positioned so as to avoidspecimen to specimen contact.7.1.1.3 For immersion at high or low temperature, insula-tion of the vessel is recommended. A separate test vessel isrecommended for each type of coating s
36、ystem being evaluated.For elevated temperature immersion, an apparatus as describedin NACE TM 0174-2002, Procedure B, is recommended.7.1.2 Test MediumThe test solution is selected to corre-spond with the anticipated service of the coating. Add enoughof the fluid to immerse one half to two thirds of
37、the test panel.The fluid level should be checked at least once every 7 days. Ifmore than 5 % of the test fluid evaporates from the test vessel,add enough fluid to maintain the level and composition of thefluid.NOTE 4When solvent or water evaporates, ensure that the additionresults in the same concen
38、tration as at the start of the test.7.1.3 Test ProcedureMaintain a temperature of 25 6 2C(77 6 4F) unless otherwise indicated by anticipated serviceconditions or by specification. Ensure that there is a minimumseparation of 25 mm (1 in.) between panels in the vessel.7.2 Method BImmersion with Temper
39、ature GradientThe practice defines 2 types of temperature gradients: increas-ing temperature from uncoated to coated side and decreasingtemperature from uncoated to coated side7.2.1 Method B1Temperature gradient with temperatureincreasing from uncoated to coated.7.2.1.1 Test ApparatusA special cylin
40、drical glass test cellis used with multiple necks to provide inlets for thermometer,heater and condenser. The test panel is coated on one side withthe exterior exposed to the ambient environment. This setupprovides a temperature gradient across the coating.NOTE 5The specific equipment drawings and o
41、peration are describedin Test Method C868 and NACE TM 0174-2002, Procedure A.7.2.1.2 Test MediumThe test solution is selected to cor-respond with the anticipated service of the coating. As this is aclosed system there is no need to replenish the solution duringthe time test specimen is immersed. Aft
42、er disassembly andrating of the panel, fresh medium is normally recommended.7.2.1.3 Test ProcedureClamp the test panels in place atthe ends of the test cell with the coating positioned against thecell interior. Fill the test cell to23 to34 of its total height withthe test solution and commence heati
43、ng.7.2.2 Method B2Temperature gradient with temperaturedecreasing from uncoated to coated.7.2.2.1 Test ApparatusUse a vessel as described in 7.2.1.1but with heating element attached to the uncoated exteriorpanel; or install panel with the uncoated side on the hot plateand the chemical container fill
44、ed with chemical to the coatedside.7.2.2.2 Periodic CyclingUse periodic cycling (heating/cooling) as requested.7.2.2.3 Test MediumThe test solution is selected to cor-respond with the anticipated service of the coating. As this is aclosed system there is no need to replenish the solution duringthe t
45、ime test specimen is immersed. After disassembly andrating of the panel, fresh medium is normally recommended.7.2.2.4 Test ProcedureClamp the test panels in place atthe ends of the test cell with the coating positioned against thecell interior. Fill the test cell to23 to34 of its total height withth
46、e test solution and commence heating.7.3 Method CImmersion Testing at Static Temperatureand Elevated Pressure:7.3.1 Test ApparatusThe test apparatus is an insulatedautoclave having an external heat source and a capability ofbeing operated at the temperatures and pressures agreed uponby purchaser and
47、 supplier.7.3.2 Test ConditionsThe test medium and pressure areselected to correspond with the anticipated service of thecoating.7.3.3 Test Procedure:7.3.3.1 Immerse the test panels23 to34 in the test fluid, oras otherwise specified between the purchaser and supplier.7.3.3.2 If the external heat sou
48、rce is needed, then raise thetemperature in the vessel to 43 6 2C (110 6 4F), or asotherwise specified between the purchaser and supplier.7.3.3.3 Raise the pressure of the autoclave to 3 bar (45 psi)or as otherwise specified between the purchaser and supplier.7.3.4 Periodic Cycling:7.3.4.1 To allow
49、initiation of discharging or recharging of avessel, the test panels are removed from the autoclave for atwo-day period once every two weeks. Panels are allowed toreach room temperature at this time.7.3.4.2 Test panels are returned to the immersion apparatusafter the cycling ends. The test apparatus is restored to theconditions described in 7.3.3 and 7.3.4.8. Examination and Evaluation8.1 Examination Schedule:8.1.1 For the exposures described in 7.1 (Method A, immer-sion with no temperature gradient) and 7.2 (Methods B1 andB2, immersion with
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