1、Designation: D1748 10Designation: 366/84Standard 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 Department of Defense.1. Scope*1.1 This test method cover
3、s 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 as
4、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 deter-m
5、ine 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 Woven
6、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 Autom
7、otive 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 48.9C (120F) for a specified number ofhours. The oil fail
8、s 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 should
9、 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 requi
10、red 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 test
11、 life of a given metal preservative, and repeattests by this test method in more than one cabinet aresometimes desirable.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.L0.03 on Corrosion Testin
12、g of Sheet Fluids Metal Processing Fluids.Current edition approved Oct. 1, 2010. Published November 2010. Originallyapproved in 1960. Last previous edition approved in 2008 as D174802(2008).DOI: 10.1520/D1748-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Cus
13、tomer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from Superintendent of Documents, U.S. Government PrintingOffice, Washington, DC 20402.4Available from Standardization Documents Order Des
14、k, Bldg. 4, Section D,700 Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.5Available from Society of Automotive Engineers, 400 Commonwealth Dr.,Warrendale, PA 15096.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C
15、700, West Conshohocken, PA 19428-2959, United States.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 against rustunder conditions of high humidity. This test method does notpresc
16、ribe 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, wet or dry, waterp
17、roof, 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(2.00-mm) sieve.6
18、.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 addition, no Class
19、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 solvent found acce
20、ptable 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 During evaluation
21、 of a sample the cabinet shall be runcontinuously with the following standard conditions beingmaintained:Air temperature:Inside the cabinet 48.9 6 1.1C (120 6 2.0F)Outside the cabinet 24.1 6 5.5C (75.4 6 10.0F)Rate of air to the cabinet0.878 6 0.028 m3/h(31.0 6 1ft3/h) at 25.0C and760 mm HgWater in
22、cabinet:Level 203.0 6 6.4mm(8.0614 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 6 0.03 rpmCover close fittingCloth layers in cover shall not be torn, co
23、ntaminated,nor contain droplets of waterCover opening to a height of 355 mm (14 in.) atthe frontABoil the water sample with 10 mL of saturated bromine water before makingthe test for sulfates.7.2 Rate of air to the cabinet, air temperature, pH, and waterlevel shall be checked and regulated if necess
24、ary twice eachday, at 7- 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 contamina-tion that should be investigated and corrected. A persistent
25、low pH alongwith a positive sulfate test indicates that the air supply is contaminatedwith sulfur oxides. In this case, the water in the cabinet should bereplaced, and a suitable alkali scrubber system installed in the air train.NOTE 5Details of the cabinet operation described in 7.1 and 7.2 andthe
26、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 protective packaging from all the panels
27、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. Identify each panel by an appropriate
28、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 panel.Tongs, metal hooks, or pieces
29、 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 test should only be thatrequired to g
30、ive 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. There should be no appreciablechan
31、ge of the finish from the 0.25 to 0.51 m (10 to 20 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 in 8.2 and 8.3, buff allfour of the ro
32、unded 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 paper under it to helpprevent contaminat
33、ion. 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.) dimension of the panel. Theabrasive
34、cloth may be held in the palm of the hand with theD1748 102fingers 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 panel.8.3.4 Polish the unnumb
35、ered or leading surface of the panelwith careful even strokes, always parallel to the 102-mm(4.0-in.) dimension. Use a polishing pressure of about 4.5 to8.9 N (1.0 to 2.0 lb). Do not scratch the surface by using shortor curved strokes. Ensure that the panel is held firmly so thatonly the abrasive cl
36、oth moves. After several polishing strokes,inspect the abrasive cloth and when necessary make anotherfold to expose a new and effective area. Continue to polish theleading surface until it contains a completely fresh surface. Thefinish should be within the range from 0.25 to 0.51 m (9.8 to20.0 in.)
37、(rms). Examine the entire surface, and if scratches orother imperfections are noted, continue polishing until cor-rected. In the same manner polish the second side of the panel,unless the test specification requires only one polished side perpanel.NOTE 6It is advisable for each operator to finish se
38、veral 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 check on surface roughness.8.3.5 Remove the dust from
39、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 followed by an ultrasonic cleaningbath procedure.) Submerg
40、e the panel completely in solventselected in 6.3 at room temperature.NOTE 7The following should be carried out periodically as a checkon surface cleanliness: Place the cleaned panel directly under a buret ona table free of vibrations and drafts. Place the buret so that its tip is exactly300 mm above
41、 the panel. The buret contains distilled water and shall havea tip of proper dimensions to deliver 0.05 6 0.01 mL of distilled water perdrop.Allow one drop of distilled water to fall onto the panel surface. If thesurface is absolutely clean, successive droplets on various parts of thesurface will sp
42、read out completely in spots of closely reproducibledimensions. A clean panel should give a spread of 21 to 23 mm for each0.05 mL of distilled water. This test is considered necessary and importantbecause of variations found in different abrasive materials and thepersonal factors involved in the pro
43、cedure require some method of checkon final results. Panels used for this cleanliness check test are not suitablefor 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 air atmospheres, cleaningand polishing of the panels should
44、be standardized in respect totime. For this reason, carry out the procedure described in8.3.2-8.3.5 one panel at a time, and after each one is prepared,store it immediately in solvent selected in 6.3 at roomtemperature until all the panels for one days operations areprepared.8.3.7 Heat the solvent s
45、elected 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 in 6.3.8.3.9 Spray the test surface, then the back of the pane
46、l, 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 Blast the edges and lightly blast the backs of thepanels with the b
47、lasting material.8.4.2 Blast the unnumbered side, or test surface, of thepanels to a fresh, uniformly abraded surface. (Operation177.9355.8 N of the blasting equipment at 40- to 80-lbpressure and holding the workpiece 50.8 to 76.2 mm (2 to 3 in.)from the nozzle is recommended.)8.4.3 Immediately afte
48、r 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 immediately upon withdrawal fromthe solvent.8.4.5 Remove remaining residue by holding t
49、he 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 6 0.5C(74.0 6 1.0F) and pour into a clean, dry 400-mL tall-formglass beaker (for example, borosilicate glass) to a height of atleast 114 mm (about 375 mL). By use of one clean
