1、Designation: D7376 10Standard Practice forOutdoor Evaluation of Wet Stack Storage Conditions onCoil-Coated Metals1This standard is issued under the fixed designation D7376; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year o
2、f last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This procedure describes the practice for determiningrelative performance of coil-coated metal in an outdoor wetstac
3、k testing environment.1.2 The purpose of this test is to evaluate relative wet stackcorrosion resistance and blistering. Substrates, pretreatments,primers, topcoats, and backers may be evaluated.1.3 This test simulates coil or stacked building panel bundlestorage at a job site in wet outdoor conditi
4、ons. The results frompanels tested during the same time period may be used tocompare products as an indicator of actual field performance.Environments with higher temperature and moisture levelsaccelerate degradation.1.4 The values stated in SI units are to be regarded as thestandard. The values giv
5、en in parentheses are for informationonly.1.5 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-priate safety and health practices and determine the applica-bility of regulator
6、y limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D610 Practice for Evaluating Degree of Rusting on PaintedSteel SurfacesD714 Test Method for Evaluating Degree of Blistering ofPaintsD1654 Test Method for Evaluation of Painted or CoatedSpecimens Subjected to Corrosive Environments
7、G7 Practice for Atmospheric Environmental Exposure Test-ing of Nonmetallic Materials3. Summary of Practice3.1 This practice is for the evaluation of relative wet stackcorrosion resistance and blistering of coil-coated metal. Thetest is to be conducted in an outdoor environment withcoil-coated panels
8、 placed on a flat surface while allowingexposure to environmental conditions such as rain, dew,humidity, and high temperatures.3.2 Panels are evaluated periodically for corrosion andblistering as specified in 6.7.4. Significance and Use4.1 This practice provides for periodic testing to comparethe re
9、lative performance of specific coatings, substrates, and/orpretreatments used on coil-coated metal for resistance to wetconditions during storage.4.2 When performed in south Florida, this practice givesaccelerated corrosion and blistering results relative to otherlocations within the continental Uni
10、ted States.4.3 This practice allows comparison of different coatings,substrates, and pretreatments when they are tested at the sametime. The results must be considered relative and do notindicate absolute performance.4.4 Because the outdoor environment shows year-to-yearclimatological, seasonal, and
11、 geographic variation, the absoluteamount of degradation based on corrosion and blistering mayvary (see Practice G7).4.5 Temperature, rain, and humidity are important factors inwet stack corrosion. Corrosion and blistering will acceleratewith increased temperature. The preferred test location is sou
12、th1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.53 on Coil Coated Metal.Current edition approved Feb. 1, 2010. Published February 2010. Originallyapproved in 2007. Last prev
13、ious edition approved in 2007 as D7376 - 07. DOI:10.1520/D7376-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM web
14、site.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.of 27N latitude in Florida. Other locations may be used, butdifferences in temperature and moisture must be considered,and the amount of corrosion and blistering are expected to va
15、ryconsiderably with climate. Test sites must have the instrumen-tation to measure and record ambient temperature and rainfallas in Practice G7.4.6 This practice is not meant to support the field storage ofcoil-coated metal in any way other than what is recommendedby the manufacturer.5. Apparatus5.1
16、The use of a wooden pallet to stack the test panels in ahorizontal position is one way to ensure rain does not puddlearound the panels. Rainwater and condensation flow down thesides of the stacks, and water is absorbed between panels bycapillary action. Excess water will drain through the slats in t
17、hepallet (see Fig. 1).5.2 The pallet is recommended to be 61 cm to 91 cm (24 in.to 36 in.) from the ground and all foliage should be removedfrom the area.5.3 Wooden two by four boards of approximate cross-sectional dimensions, 4 cm by 9 cm (1.5 in by 3.5 in.) and ofthe required length are placed on
18、top of the stacks (see Fig. 1).The pallets and boards shall be composed of untreated wood toavoid any influence from the treatment.6. Procedure6.1 A wooden pallet or some flat surface with slats for waterdrainage is assembled in the required outdoor environmentalconditions.6.2 Test panels shall be g
19、athered and cut to the required size.A size of at least 15 cm by 15 cm (6 in. by 6 in.) is required.Duplicates of each panel are required to allow contact betweenthe topside and backside of the same coil. Panels to becompared must be cut on the same metal shear with edge burrsoriented equivalently.6
20、.3 It is recommended that a minimum of two extra panelsbe placed at the top and bottom of the stack to act as a barrierto any influences from the wood or water accumulation.6.4 The test panel numbers shall be recorded along withinformation such as coater, paint code, substrate, primer,pretreatment,
21、and date of test initiation.6.5 The test panels shall be stacked on top of one anotherwith the convex side facing upward against the backer of aduplicate panel. A second set of duplicate panels may also betested, and it shall be stacked in the same fashion as the first.A second set of duplicate pane
22、ls is highly recommended aswell as positive and negative controls representing knownperformance levels.6.6 Each stack of test panels shall be no greater than 5 cm(2 in.) in height and shall be weighted down with a singlewooden two by four with cross-sectional dimensions, 4 cm by9 cm (1.5 in. by 3.5
23、in.) on top of each stack or spanning twoor more stacks.6.7 It is recommended that panels be evaluated for corrosionand blistering monthly in accordance with Test Methods D610,D714, and D1654 Procedure B, until a suggested total test timeof six months has elapsed or until a time agreed upon betweenc
24、ustomer and supplier is complete. Evaluation of field corro-sion and blistering is considered to be the most appropriate forthis test, but edge results may also be assessed. Edge resultsmay be significantly influenced by burr differences. Corrosionratings shall include any visible red or white corro
25、sion prod-ucts.7. Report7.1 The report section shall contain the following informa-tion when available. In many cases, specific information aboutthe materials used or preparation of the test specimens is notavailable to commercial testing agencies.7.1.1 Included in the test reports shall be the loca
26、tion wherethe test is performed, the start date of the test and the date ofthe evaluation.7.1.2 The test report shall include a measurement of totalrainfall and number of days with rain during the test period atthe test location. A rain day shall be considered any day with0.8 mm (0.03 in.) or greate
27、r of rainfall accumulation.7.1.3 The test report shall include the average daily maxi-mum temperature and average daily minimum relative humid-ity during the test period.7.1.4 The test report shall include the manufacturer of theproduct and any experimental, raw material, or coating processchanges f
28、or the product being tested.7.1.5 The test report shall include the coating paint code,substrate, primer, backer and pretreatment used. Dry filmcoating thickness (DFT) and pretreatment weight may also beimportant and should be reported, if available.7.1.6 Samples shall be evaluated for corrosion and
29、 blisters.Any notable changes shall be recorded. Corrosion and blisters,including any red or white corrosion products, shall be rated inaccordance with Test Methods D1654, Procedure B, D610, andD714. The results from duplicate pairs of panels shall bereported separately to illustrate test variabilit
30、y, if any.7.1.7 A statement of compliance shall be noted and anyexceptions to the procedure shall be noted in the report.NoteLevel position for test purposes only. Level storage of building panels inwet conditions is not recommended.FIG. 1 Illustration of Wet Stack Test Placed Horizontally (Level)on
31、 a PalletD7376 1028. Keywords8.1 blistering; coil-coated; corrosion; wet stackASTM International takes no 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 valid
32、ity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.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 comme
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34、ot received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple co
35、pies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D7376 103
