1、Designation: F482 09 (Reapproved 2014)Standard Practice forCorrosion of Aircraft Metals by Total Immersion inMaintenance Chemicals1This standard is issued under the fixed designation F482; the number immediately following the designation indicates the year of originaladoption or, in the case of revi
2、sion, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers the determination of the corrosive-ness of tank-type aircraft maintenance chemicals
3、 on aircraftmetals and the corrodibility of metals in these maintenancechemicals with time. The determination is made under condi-tions of total immersion by a combination of weight changemeasurements and visual qualitative determinations of change.1.2 The values stated in SI units are to be regarde
4、d as thestandard. The values given in parentheses 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-priate safety and health practices and determine
5、 the applica-bility of regulatory limitations prior to use. For specificprecautions, see Section 6.2. Referenced Documents2.1 ASTM Standards:2D235 Specification for Mineral Spirits (Petroleum Spirits)(Hydrocarbon Dry Cleaning Solvent)D329 Specification for AcetoneD1193 Specification for Reagent Wate
6、rE1 Specification for ASTM Liquid-in-Glass Thermometers3. Significance and Use3.1 This practice not only provides information on theaccumulated effects of corrosion at specific time periods undera given set of conditions, but also provides information on theinitial rate of corrosion of virgin metal,
7、 the corrosion rate ofmetal per unit time after long exposure, and the initialcorrosion rate of virgin metal after long exposure of thecorroding fluid to metal. The test also provides a means ofdetermining the direction corrosion will take with time, al-though causes for increase or decrease in the
8、corrosiveness andcorrodibility of media and metal (such as passive film forma-tion or destruction, depletion of corrosive contaminate, and soforth) as a function of time are not given.4. Apparatus4.1 Wide-Mouth Glass Jar or Flask of suitable sizes (3000to 4000 mL), capable of accommodating a reflux
9、condenser, athermometer, and a specimen support system. Fig. 1 shows atypical arrangement, but any array meeting the provisions of4.2 4.5 is acceptable.4.1.1 If agitation is required, use an apparatus capable ofaccepting a stirring mechanism, such as a magnetic stirrer orimpeller. Choose the glass j
10、ar or flask such that the specimenswill remain fully immersed in a vertical position during thetest, and the ratio of area of immersed metal to volume ofsolution will be in accordance with 9.1.4.2 Specimen-Supporting Devicea glass or fluorocarbonplastic supporting system designed to keep the specime
11、n fullyimmersed while assuring free contact with the corrodingsolution, and designed to physically isolate the specimens fromeach other.4.3 Condensera glass reflux condenser of the water-cooled type, having a condenser jacket 200 to 300 mm inlength.4.4 Constant-Temperature DeviceUse any suitable reg
12、u-lated heating device (mantle, hot plate, or bath) to maintain thesolution at the required temperature.4.5 Thermometeran ASTM 75-mm (3-in.) immersionthermometer having a range from 18 to 150C (0 to 302F)and conforming to requirements for Thermometer 1F in accor-dance with Specification E1.1This pra
13、ctice is under the jurisdiction of ASTM Committee F07 on Aerospaceand Aircraft and is the direct responsibility of Subcommittee F07.07 on Qualifica-tion Testing of Aircraft Cleaning Materials.Current edition approved Dec. 1, 2014. Published December 2014. Originallypublished in 1977. Last previous e
14、dition approved in 2009 as F482 09. DOI:10.1520/F0482-09R14.2For 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.C
15、opyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15. Reagents and Materials5.1 Mineral Spirits (Petroleum Spirits) (Hydrocarbon DryCleaning Solvent, conforming to Specification D235.5.2 Methyl n-propyl ketone (MPK).35.3 Acetone, conformi
16、ng to Specification D329.5.4 Reagent Water, conforming to Specification D1193.6. Safety Precautions6.1 The solvents used in the cleaning of test specimens areflammable and harmful if inhaled. Keep away from sparks andopen flames.Avoid breathing vapors and prolonged or repeatedcontact with the skin.
17、Use with adequate ventilation.6.2 Flammable solvents, acids, or alkalis, or other toxiccompounds are occasionally found in the material used foraircraft maintenance. Take suitable precautions to preventpersonnel injury.7. Test Specimens7.1 The test specimens of a given alloy shall be taken fromthe s
18、ame sheet stock and shall measure 50.8 by 25.4 by 1.6 mm(2 by 1 by 0.06 in.) with a 3.2-mm (0.125-in.) diametermounting hole suitably located at one end of the specimen.Testat least two and preferably three replicates in each concentra-tion of maintenance chemical solution in accordance with 9.2.The
19、 total area of the specimen shall be taken as 28.2 cm2(4.4in.2).8. Test Specimen8.1 Preheat the test specimens to 60 6 2C (150 6 5F) andimmerse in a beaker containing Mineral Spirits, Type II,conforming to Specification D235. Swab the surface of theindividual specimen thoroughly using clean forceps
20、to hold thespecimen and the cotton swab.8.2 Shake off the excess solvent. Transfer and immerse thetest specimens separately several times in a beaker of methyln-propyl ketone.8.3 Shake off excess methyl n-propyl ketone and dry in avacuum desiccator or in a low temperature oven at 37.7 6 3C(100 6 5F)
21、 for 15 min.9. Conditioning9.1 Volume of SolutionThe volume of solution shall be500 mL per specimen. Use fresh solution for each set ofreplicates.9.2 Solution Concentration:9.2.1 Unless otherwise specified, test the specimens insolutions of the maintenance chemical in the concentratedas-received con
22、dition and at the recommended dilution usingdistilled or deionized water conforming to SpecificationD1193, Type IV. (For solid materials, concentrated conditionshall mean in a saturated solution of the solid material.) In casethe material is not soluble to the extent noted, record this factand conti
23、nue with the test.9.2.2 Test diphase materials with an appropriate amount ofeach phase loaded into the test vessel to simulate use condi-tions. Totally immerse the corrosion specimens in the workingphase of the maintenance chemical.9.2.3 If water is not used as the diluent, record the type andspecif
24、ication of diluent used in the test.9.3 TemperatureUnless otherwise specified, the tempera-ture shall be 37.7 6 3C (100 6 2F).9.4 Test DurationTotal test duration shall be 168 h, withspecimens being added or removed at intermediate intervals.9.5 If the maintenance chemical is to be used with agitati
25、on,also test the specimens with appropriate agitation to simulateuse conditions.3The sole source of supply of Methyl n-Propyl Ketone (MPK) known to thecommittee at this time is Eastman Chemical Company, Kingsport, TN, USA. If youare aware of alternative suppliers, please provide this information to
26、ASTMInternational Headquarters. Your comments will receive careful consideration at ameeting of the responsible technical committee,1which you may attend.A = CondenserB = Stirring mechanismC = Containing vesselD = Specimen holderE = ThermometerF = Metal specimenG = Maintenance chemical solutionNOTE
27、1THIS IS ONE FORM THAT THE EQUIPMENT CAN TAKE, AND IS NOTMANDATORY.ANY ARRAY MEETING THE REQUIREMENTS OF 4.2 4.5 is acceptable.FIG. 1 Test ApparatusF482 09 (2014)210. Procedure10.1 Weigh four of five specimens (S1, S2, S3, and S4)ofthesame alloy to the nearest 0.1 mg. Record the weights S1W1, S2W1,
28、S3W1, S4W1. Retain the fifth specimen of each alloy forcomparison purposes.10.2 Immerse three of the specimens (S1, S2, and S3)inthetest solution using only specimens of the same alloy in thecontaining vessel. Retain S4for use in accordance with 10.5.10.3 At the end of 48-h exposure time, remove S1a
29、ndproceed as follows:10.3.1 Rinse thoroughly under hot tap water, 49 to 60C(120 to 140F), while scrubbing with a stiff bristle brush.Follow with distilled or deionized water conforming to Speci-fication D1193, Type IV at room temperature.10.3.2 Rinse with a stream of acetone conforming to Speci-fica
30、tion D329 from a wash bottle and dry.10.3.3 If corrosion deposits are still adhered, remove corro-sion products in accordance with AnnexA1 and AnnexA2 andrinse dry in accordance with 10.3.1 and 10.3.2.10.3.4 Weigh to the nearest 0.1 mg and record as S1W2.Ifthe specimen has been treated in accordance
31、 with Annex A1and Annex A2, subtract any weight losses of the controlspecimen of Annex A1 and Annex A2 from the weight loss ofthe specimen.10.3.5 Calculate the weight loss of the panel as WL. S1= S1W1 S1W2.10.4 At the end of 120-h exposure time, remove S2andproceed in accordance with 10.3. Record th
32、e weight loss as S2W2.10.5 Also at the end of 120-h exposure time, add S4to thereaction vessel.10.6 At the end of 168-h exposure time, remove S3and S4from the solution and proceed as follows:10.6.1 Proceed in accordance with 10.3 for S4and recordthe weight loss as S4W2.10.6.2 For S3, rinse in accord
33、ance with 10.3.1 and 10.3.2,then examine for and record the following visible changes incomparison with the fifth virgin specimen:10.6.2.1 Discoloration and dulling,10.6.2.2 Etching,10.6.2.3 Presence of accretions and relative amounts,10.6.2.4 Pitting, and10.6.2.5 Presence of selective or localized
34、attack.10.6.3 If any corrosion deposits remain, remove these prod-ucts from S3in accordance with Annex A1 and Annex A2.Rinse with distilled water conforming to Specification D1193,Type IV followed by acetone conforming to SpecificationD329 and dry.10.6.4 Weigh to the nearest 0.1 mg and calculate the
35、 weightloss as W3. If the specimen has been treated in accordance withAnnex A1 and Annex A2, subtract any weight losses of thecontrol specimen of AnnexA1 and AnnexA2, from the weightloss of the test specimen.11. Report11.1 Report the following data for each test performed:11.1.1 Name and type of mai
36、ntenance chemical tested.11.1.2 Concentrations, diluent used, and other conditions oftest peculiar to maintenance chemical type.11.1.3 Alloy type, surface treatment and condition, andnumber of specimens tested.11.1.4 Temperature, duration of test, and agitation if any.11.1.5 Average corrosion rate,
37、R1, R2, R3, R4, or weight lossin milligrams per square centimetre per day for each specimenwhere:R 5W/surface area of panel incm2total exposure time of panel2411.1.6 Range in weight losses.11.1.7 Effect of time on liquid corrosiveness and metalcorrodibility calculated in accordance with Annex A3.11.
38、1.8 Appearance before and after removal of corrosionproducts with regard to the following:11.1.8.1 Discoloration and dulling,11.1.8.2 Etching,11.1.8.3 Presence of accretions and relative amounts,11.1.8.4 Pitting, and11.1.8.5 Presence of selective or localized attack.12. Keywords12.1 aircraft metals;
39、 corrosion rates as weight loss persurface unit divided by exposure time per day; in concentrate;in use dilution; liquid corrosiveness; metal corrodibility; tank-type chemicals; temperature control; time control; total immer-sion corrosion; visual corrosive deteriorationF482 09 (2014)3ANNEXES(Mandat
40、ory Information)A1. CHEMICAL METHODS FOR CLEANING CORRODED SPECIMENSA1.1 After scrubbing to remove loosely attached corrosionproducts, treat the specimens as follows. A blank metalspecimen shall be run at the same time to ensure weight lossesincurred by cleaning the corroded specimens are not includ
41、edin the weight loss determination.A1.1.1 Aluminum and Its AlloysImmerse the specimenfor 5 min in a water solution containing 2 weight % of chromicacid and orthophosphoric acid (85 %) maintained at 79 6 3C(175 6 5F). Rinse in water to remove acid and brush with stiffbristle brush to remove loosened
42、materials.A1.1.2 Copper and Nickel AlloysImmerse the specimenfor 2 to 3 min in hydrochloric acid (1 + 1) or sulfuric acid(1 + 10) at room temperature. Scrub with a bristle brush underrunning water and dry.A1.1.3 Magnesium AlloysImmerse the specimen for 1min in chromic acid (20 weight %) to which has
43、 been added,with agitation, 1 weight % of silver nitrate in solution form.Operate the bath at 93 to 100C (200 to 212F).A1.1.4 Iron and SteelImmerse the specimen for 2 to 3min in a boiling solution of ammonium citrate (10 weight %).A1.1.5 Stainless SteelImmerse the specimen for 5 min ina solution of
44、nitric acid (30 volume %) at a temperature of 49to 54C (120 to 130F).A2. METHOD FOR ELECTROLYTIC CLEANING OF CORROSION TEST SPECIMENS AFTER EXPOSUREA2.1 This method is known to be suitable for the metals andalloys listed in Table A2.1; other metals or alloys must beevaluated before use.A2.2 After sc
45、rubbing, remove loosely attached corrosionproducts. Treat the specimen as a cathode in hot, dilutedsulfuric acid under the following condition:Test solution sulfuric acid (5 weight %)Inhibitor 2 mL organic inhibitor/litre of solutionAnode carbonCathode test specimenCathode current density 20 A/dm2(6
46、.5 A/0.325 dm2)Temperature 74C (165F)Exposure period 3 minA2.3 After the electrolytic treatment, scrub the specimens,while wet, with a stiff bristle brush. Run a blank metalspecimen at the same time to ensure weight losses incurred bycleaning the corroded specimens are not included in the weightloss
47、 determination.A2.4 Note the possible redeposition of adherent metal fromreducible corrosion products (and thus lowering the apparentweight loss) resulting from this electrolytic treatment.However, general experience has indicated that in most casesof corrosion in liquids, the possible errors from t
48、his source arenot likely to be serious. Use either 2 mL of any proprietaryinhibitor or about 0.5 g/L of such inhibitors as diorthotolylthiourea, quinoline ethiodide, or beta-naphthol quinoline.TABLE A2.1 Weight Losses of 0.5-dm2Specimens Subjected toElectrolytic Cleaning TreatmentMaterial Total Weig
49、ht Loss, gCopper-nickel-zinc (75-20-5) 0.0000Brass (admiralty) 0.0001Brass (red) 0.0000Brass (yellow) 0.0002Bronze (phosphor, 5 % tin) 0.0000Bronze (silicon) 0.0002Bronze (case) (85-5-5-5) 0.0010Copper 0.0001Copper-nickel (70-30) 0.0000Iron and steel 0.0003Nickel-molybdenum-iron (60-20-20)0.0004Nickel-chromium-iron (80-13-7) 0.0000Lead (chemical) 0.0030Nickel-copper (70-30) 0.0000Nickel 0.0011Stainless steel 0.0000Tin 0.0003Magnesium and zinc too high to be usefulF482 09 (2014)4A3. CRITERIA FOR CORROSIVENESS OF ENVIRONMENT AND METAL CORRODIB
