1、Designation: D1748 10 (Reapproved 2015)Standard Test Method forRust Protection by Metal Preservatives in the HumidityCabinet1This standard is issued under the fixed designation D1748; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、 the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 This test method co
3、vers the evaluation of the rust-preventive properties of metal preservatives under conditionsof high humidity.1.2 The values stated in SI units are to be regarded as thestandard except where the test apparatus or consumable partsare only available in other units. In such cases these will beregarded
4、as standard. The values given in parentheses are forinformation only.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 consult andestablish appropriate safety and health practices and dete
5、r-mine the applicability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A109/A109M Specification for Steel, Strip, Carbon (0.25Maximum Percent), Cold-RolledD512 Test Methods for Chloride Ion In WaterD516 Test Method for Sulfate Ion in WaterE11 Specification for Wov
6、en Wire Test Sieve Cloth and TestSievesE323 Specification for Perforated-Plate Sieves for TestingPurposes2.2 Federal Standards:3QQ-S-698 Steel Sheet and Strip, Low Carbon2.3 Military Standards:4MIL-C-5646F Cloth, AirplaneMIL-C-15074E Corrosive Preventive Compound FingerPrint Remover2.4 Society of Au
7、tomotive Engineers:5SAE 1009C Tee Reducer, Bulkhead on Side, Flareless Tube3. Summary of Test Method3.1 Steel panels are prepared to a prescribed surface finish,dipped in the test oil, allowed to drain, and then suspended ina humidity cabinet at 48.9 C (120 F) for a specified numberof hours. The oil
8、 fails or passes the test in accordance with thesize and number of rust dots on the test surfaces of the panels.4. Significance and Use4.1 This test method is used for measuring the relativeabilities of metal preservatives to prevent the rusting of steelpanels under conditions of high humidity. It s
9、hould not berelied upon to predict the effectiveness of a metal preservativein which high humidity is not the principal factor in the rusting.4.2 Comparisons made by this test method should normallybe limited to similar metal preservative combinations designedfor similar applications. The test life
10、required for each type ofmetal preservative and for each intended application should bebased on actual experience with that type of preservative in theintended service.4.3 Since the precision of the test method appears to be lessthan desired, a number of repeat tests may be necessary toestablish the
11、 test life of a given metal preservative, and repeattests by this test method in more than one cabinet aresometimes desirable.4.4 The data obtained from this accelerated test is of interestonly in eliminating the most unsuitable materials or forindicating a probable relative order of protection agai
12、nst rustunder conditions of high humidity. This test method does not1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.L0.03 on Corrosion Testing of Sheet Metal Processing Fluids.Cur
13、rent edition approved July 1, 2015. Published July 2015. Originally approvedin 1960. Last previous edition approved in 2010 as D1748 10. DOI: 10.1520/D1748-10R15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book
14、of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http:/www.access.gpo.gov.4Available from Standardization Docu
15、ments Order Desk, Bldg. 4, Section D,700 Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.5Available from SAE International (SAE), 400 Commonwealth Dr., Warrendale,PA 15096, http:/www.sae.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. Un
16、ited States1prescribe the exposure periods to be used for a specific product,nor the interpretation to be given to the results.5. Apparatus5.1 The apparatus shall conform to the details shown in theAnnex A1.6. Panel Cleaning Materials6.1 Aluminum Oxide Cloth, 240 grit.NOTE 1Paper-backed abrasives, w
17、et or dry, waterproof, or iron oxideabrasives are prohibited.6.2 Silica Sand, white, dry, sharp, chloride free, or alumi-num oxide, blasting grade. (The size shall be such that it meetsthe following sieve requirements of Specifications E11 andE323.6.2.1 One hundred percent must pass through a No. 10
18、(2.00 mm) sieve.6.2.2 Minimum of 90 % must pass through a No. 20(850 m) sieve.6.2.3 Maximum of 10 % permitted to pass through a No. 50(300 m) sieve.6.3 CleanersSelect a cleaning media and method, whichis safe, non-film forming and which does not in any way attackor etch the surface chemically. In ad
19、dition, no Class 1 ozonedepleting substances conforming to Section 602(a) of the CleanAir Act Amendments of 1990 (42USC7671a) as identified inSection 326 of PL 102-484 should be used. Use a procedure asoutlined in Test Method F22 to judge the merit of the selectedcleaning technique.NOTE 2A typical s
20、olvent found acceptable for this purpose is hexaneor Stoddard solvent.NOTE 3The original precision was developed using a combination ofpetroleum naphtha and methanol. These are no longer used due to toxicityissues.6.4 Gauze, lint free cotton or gauze pads.7. Humidity Cabinet Operating Conditions7.1
21、During evaluation of a sample the cabinet shall be runcontinuously with the following standard conditions beingmaintained:Air temperature:Inside the cabinet 48.9 C 1.1 C (120 F 2.0 F)Outside the cabinet 24.1 C 5.5 C (75.4 F 10.0 F)Rate of air to the cabinet0.878 m 0.028 m3/h(31.0ft1ft3/h) at 25.0 C
22、and 760 mmHgWater in cabinet:Level 203.0 mm 6.4 mm (8.0 in. 14 in.)pH 5.5 to 7.5Oil content clear with no evidence of oilChlorides less than 20 ppm (Test MethodsD512)Sulfates and sulfitesAless than 20 ppm as sulfate (TestMethod D516)Speed of rotating 0.33 r min 0.03 r minCover close fittingCloth lay
23、ers in cover shall not be torn, contaminated,nor contain droplets of waterCover opening to a height of 355 mm (14 in.) at the frontABoil the water sample with 10 mL of saturated bromine water before making thetest for sulfates.7.2 Rate of air to the cabinet, air temperature, pH, and waterlevel shall
24、 be checked and regulated if necessary twice eachday, at 7 h to 8 h intervals. Remaining standard conditions shallbe closely checked once each week. The pH measurement maybe made with wide-range indicator paper.NOTE 4Values for pH outside the limits shown indicate contaminationthat should be investi
25、gated and corrected. A persistent low pH along witha positive sulfate test indicates that the air supply is contaminated withsulfur oxides. In this case, the water in the cabinet should be replaced, anda suitable alkali scrubber system installed in the air train.NOTE 5Details of the cabinet operatio
26、n described in 7.1 and 7.2 andthe details of panel preparation described in Section 8, must be carefullycarried out. Only by such standardization can results be obtained that aresignificant and comparable to those run at another time or in anotherlaboratory.8. Panel Preparation8.1 Remove the protect
27、ive packaging from all the panels tobe used for a particular day and wash away the rust preventivematerial in a beaker of solvent selected in 6.3 (swabbing ispermissible using materials defined in 6.4). Carefully inspecteach panel and use only those which comply with requirementsgiven in A1.10. Iden
28、tify each panel by an appropriate numberin the right-hand lower corner, outside of the significant area,or by attaching a small metal tag to the outside wire hook afterthe panel is polished.8.2 The following are pertinent to the polishing operations:8.2.1 Do not allow the bare fingers to touch the p
29、anel.Tongs, metal hooks, or pieces of lint-free paper are suitablehelpers for manipulating and holding the panel.8.2.2 Always keep the panel on a clean, dry surface.8.3 Alternative Surface FinishesPolishing:8.3.1 The amount of polishing of the panel by the operatorconducting the humidity cabinet tes
30、t should only be thatrequired to give it a fresh, clean, and active surface. Thisrequires only a few minutes per panel. A fast-moving beltsander should not be used since the heat of friction may changethe surface characteristics of the panel. Surface finish limits forthe panel are not defined here.
31、There should be no appreciablechange of the finish from the 0.25 m to 0.51 m (10 m to20 m) obtained by the original surface grinding A1.10.1.3.8.3.2 Divide the 240 grit aluminum oxide abrasive clothinto convenient size strips for the subsequent polishing opera-tions. Observing the precautions given
32、in 8.2 and 8.3, buff allfour of the rounded edges with even strokes in the direction ofeach edge. Ream out the two holes used for suspension andwipe clean, using gauze wet with solvent selected in 6.3.8.3.3 While polishing, place the panel on a clean, drysurface with a suitable thickness of clean pa
33、per under it to helpprevent contamination. The panel may be held by hand, usingpaper between the fingers and the steel surface. Alternatively itmay be held in a special holder such as a wooden block, havingabout a 1.6-mm (116-in.) depression slightly larger in area thanthe 51- by 102-mm (2- by 4-in.
34、) dimension of the panel. Theabrasive cloth may be held in the palm of the hand with thefingers applying pressure to the panel. Alternatively, thealuminum oxide cloth may be held on a block of sizeconvenient to the hand and convenient for polishing withsmooth strokes without marking the ends of the
35、panel.8.3.4 Polish the unnumbered or leading surface of the panelwith careful even strokes, always parallel to the 102 mmD1748 10 (2015)2(4.0 in.) dimension. Use a polishing pressure of about 4.5 N to8.9 N (1.0 lb to 2.0 lb). Do not scratch the surface by usingshort or curved strokes. Ensure that th
36、e panel is held firmly sothat only the abrasive cloth moves. After several polishingstrokes, inspect the abrasive cloth and when necessary makeanother fold to expose a new and effective area. Continue topolish the leading surface until it contains a completely freshsurface. The finish should be with
37、in the range from 0.25 m to0.51 m (9.8 in. to 20.0 in.) (rms). Examine the entiresurface, and if scratches or other imperfections are noted,continue polishing until corrected. In the same manner polishthe second side of the panel, unless the test specificationrequires only one polished side per pane
38、l.NOTE 6It is advisable for each operator to finish several panels todetermine exactly what technique is required to attain the correct surfacefinish using a profilometer or other surface roughness gage. Aftertechniques have been established, the use of visual comparison standardsis sufficient as a
39、check on surface roughness.8.3.5 Remove the dust from the abrasive operation, usingclean gauze wet with solvent selected in 6.3. Finally, wipe withclean surgical gauze until there is no dark stain on a cleansection of the gauze. Remove any dust in the holes by use of apipe cleaner. (This may be foll
40、owed by an ultrasonic cleaningbath procedure.) Submerge the panel completely in solventselected in 6.3 at room temperature.NOTE 7The following should be carried out periodically as a check onsurface cleanliness: Place the cleaned panel directly under a buret on atable free of vibrations and drafts.
41、Place the buret so that its tip is exactly300 mm above the panel. The buret contains distilled water and shall havea tip of proper dimensions to deliver 0.05 mL 6 0.01 mL of distilled waterper drop. Allow one drop of distilled water to fall onto the panel surface.If the surface is absolutely clean,
42、successive droplets on various parts ofthe surface will spread out completely in spots of closely reproducibledimensions. A clean panel should give a spread of 21 mm to 23 mm foreach 0.05 mL of distilled water. This test is considered necessary andimportant because of variations found in different a
43、brasive materials andthe personal factors involved in the procedure require some method ofcheck on final results. Panels used for this cleanliness check test are notsuitable for use in the protection test.8.3.6 To minimize differences in activity of the steel sur-faces as a result of time in various
44、 air atmospheres, cleaningand polishing of the panels should be standardized in respect totime. For this reason, carry out the procedure described in 8.3.2 8.3.5 one panel at a time, and after each one is prepared, storeit immediately in solvent selected in 6.3 at room temperatureuntil all the panel
45、s for one days operations are prepared.8.3.7 Heat the solvent selected in 6.3 so that the solvent willevaporate from the panels immediately upon withdrawal fromthe solvent.8.3.8 Remove remaining residue by holding the panels in arack at 20 from the vertical and spraying downward withsolvent selected
46、 in 6.3.8.3.9 Spray the test surface, then the back of the panel, andthe test surface again.8.3.10 Rinse the panels in hot solvent selected in 6.3, andstore in a desiccator until cool.8.3.11 Use panels the same day as prepared.8.4 Alternative Surface FinishesSand or Aluminum OxideBlasting:8.4.1 Blas
47、t the edges and lightly blast the backs of thepanels with the blasting material.8.4.2 Blast the unnumbered side, or test surface, of thepanels to a fresh, uniformly abraded surface. (Operation177.9 N to 355.8 N of the blasting equipment at 40 lb to 80 lbpressure and holding the workpiece 50.8 mm to
48、76.2 mm (2 in.to 3 in.) from the nozzle is recommended.)8.4.3 Immediately after blasting, place the panels in abeaker of nonreactive solvent or an ultrasonic cleaning bathcontaining nonreactive solvent.8.4.4 Heat the solvent selected in 6.3 so that the solvent willevaporate from the panels immediate
49、ly upon withdrawal fromthe solvent.8.4.5 Remove remaining residue by holding the panels in arack at 20 from the vertical and spraying downward withsolvent selected in 6.3.8.4.6 Spray the test surface, then the back of the panel, andthe test surface again.8.4.7 Rinse the panels in hot solvent selected in 6.3, andstore in a desiccator until cool.8.4.8 Panels are to be used the same day as prepared.9. Procedure9.1 Bring the sample oil to a temperature of 23.3 C 60.5 C (74.0 F 6 1.0 F) and pour into a clean, dry 400 mLtall-f
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