1、Designation: F 482 03Standard Test Method forCorrosion of Aircraft Metals by Total Immersion inMaintenance Chemicals1This standard is issued under the fixed designation F 482; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea
2、r of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the corro-siveness of tank-type aircraft maintenance chemicals on a
3、ir-craft metals and the corrodibility of metals in these mainte-nance chemicals with time. The determination is made underconditions of total immersion by a combination of weightchange measurements and visual qualitative determinations ofchange.1.2 The values stated in SI units are to be regarded as
4、 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 the
5、 applica-bility of regulatory limitations prior to use. For specificprecautions, see Section 5.2. Referenced Documents2.1 ASTM Standards:D 235 Specification for Mineral Spirits (Petroleum Spirits)(Hydrocarbon Dry Cleaning Solvent)2D 329 Specification for Acetone2D 740 Specification for Methyl Ethyl
6、Ketone2D 1193 Specification for Reagent Water3E 1 Specification for ASTM Thermometers43. Significance and Use3.1 This test method not only provides information on theaccumulated effects of corrosion at specific time periods undera given set of conditions, but also provides information on theinitial
7、rate of corrosion of virgin metal, 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 cause
8、s for increase or decrease in the 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),
9、capable of accommodating a reflux 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 stir
10、rer orimpeller. Choose the glass jar 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 8.1.4.2 Specimen-Supporting Devicea glass or fluorocarbonplastic supporting s
11、ystem designed to keep the specimen 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-Temp
12、erature DeviceUse any suitable regu-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-dan
13、ce with Specification E 1.5. Safety Precautions5.1 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. Use with adequate ventilation.1This test method is
14、under the jurisdiction of ASTM Committee F07 onAerospace and Aircraft and is the direct responsibility of Subcommittee F07.07 onQualification Testing of Aircraft Cleaning Materials.Current edition approved Apr. 10, 2003. Published May 2003. Originallypublished in 1977. Last previous edition approved
15、 in 1999 as F 482 84 (1999)e1.2Annual Book of ASTM Standards, Vol 06.04.3Annual Book of ASTM Standards, Vol 11.01.4Annual Book of ASTM Standards, Vol 14.03.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.2 Flammable solvents, acids
16、, or alkalis, or other toxiccompounds are occasionally found in the material used foraircraft maintenance. Take suitable precautions to preventpersonnel injury.6. Test Specimens6.1 The test specimens of a given alloy shall be taken fromthe same sheet stock and shall measure 50.8 by 25.4 by 1.6 mm(2
17、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 8.2.The total area of the specimen shall be taken as 28.2 cm2(4.4
18、in.2).7. Test Specimen7.1 Preheat the test specimens to 60 6 2C (150 6 5F) andimmerse in a beaker containing Mineral Spirits, Type II,conforming to Specification D 235. Swab the surface of theindividual specimen thoroughly using clean forceps to hold thespecimen and the cotton swab.7.2 Shake off the
19、 excess solvent. Transfer and immerse thetest specimens separately several times in a beaker of methylethyl ketone conforming to Specification D 740.7.3 Shake off excess methyl ethyl ketone and dry in avacuum desiccator or in a low temperature oven at 37.7 6 3C(100 6 5F) for 15 min.8. Conditioning8.
20、1 Volume of SolutionThe volume of solution shall be500 mL per specimen. Use fresh solution for each set ofreplicates.8.2 Solution Concentration:8.2.1 Unless otherwise specified, test the specimens insolutions of the maintenance chemical in the concentratedas-received condition and at the recommended
21、 dilution usingdistilled or deionized water conforming to SpecificationD 1193, 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 continue with the test.8.2.2 Test
22、 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.8.2.3 If water is not used as the diluent, record the type andspecification of diluent used in t
23、he test.8.3 TemperatureUnless otherwise specified, the tempera-ture shall be 37.7 6 3C (100 6 2F).8.4 Test DurationTotal test duration shall be 168 h, withspecimens being added or removed at intermediate intervals.8.5 If the maintenance chemical is to be used with agitation,also test the specimens w
24、ith appropriate agitation to simulateuse conditions.9. Procedure9.1 Weigh four of five specimens (S1, S2, S3, and S4)ofthesame alloy to the nearest 0.1 mg. Record the weights S1W1,S2W1, S3W1, S4W1. Retain the fifth specimen of each alloy forcomparison purposes.9.2 Immerse three of the specimens (S1,
25、 S2, and S3)inthetest solution using only specimens of the same alloy in thecontaining vessel. Retain S4for use in accordance with 9.5.9.3 At the end of 48-h exposure time, remove S1andproceed as follows:9.3.1 Rinse thoroughly under hot tap water, 49 to 60C (120to 140F), while scrubbing with a stiff
26、 bristle brush. Followwith distilled or deionized water conforming to SpecificationD 1193, Type IV at room temperature.9.3.2 Rinse with a stream of acetone conforming to Speci-fication D 329 from a wash bottle and dry.A = CondenserB = Stirring mechanismC = Containing vesselD = Specimen holderE = The
27、rmometerF = Metal specimenG = Maintenance chemical solutionNOTETHIS 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 ApparatusF4820329.3.3 If corrosion deposits are still adhered, remove corro-sion products in accord
28、ance with Annex A1 and Annex A2 andrinse dry in accordance with 9.3.1 and 9.3.2.9.3.4 Weigh to the nearest 0.1 mg and record as S1W2.Ifthespecimen has been treated in accordance with Annex A1 andAnnex A2, subtract any weight losses of the control specimenof Annex A1 and Annex A2 from the weight loss
29、 of thespecimen.9.3.5 Calculate the weight loss of the panel as WL.S1= S1W1 S1W2.9.4 At the end of 120-h exposure time, remove S2andproceed in accordance with 9.3. Record the weight loss asS2W2.9.5 Also at the end of 120-h exposure time, add S4to thereaction vessel.9.6 At the end of 168-h exposure t
30、ime, remove S3and S4from the solution and proceed as follows:9.6.1 Proceed in accordance with 9.3 for S4and record theweight loss as S4W2.9.6.2 For S3, rinse in accordance with 9.3.1 and 9.3.2, thenexamine for and record the following visible changes incomparison with the fifth virgin specimen:9.6.2
31、.1 Discoloration and dulling,9.6.2.2 Etching,9.6.2.3 Presence of accretions and relative amounts,9.6.2.4 Pitting, and9.6.2.5 Presence of selective or localized attack.9.6.3 If any corrosion deposits remain, remove these prod-ucts from S3in accordance with Annex A1 and Annex A2.Rinse with distilled w
32、ater conforming to Specification D 1193,Type IV followed by acetone conforming to SpecificationD 329 and dry.9.6.4 Weigh to the nearest 0.1 mg and calculate the weightloss as W3. If the specimen has been treated in accordance withAnnex A1 and Annex A2, subtract any weight losses of thecontrol specim
33、en of Annex A1 and Annex A2, from the weightloss of the test specimen.10. Report10.1 Report the following data for each test performed:10.1.1 Name and type of maintenance chemical tested.10.1.2 Concentrations, diluent used, and other conditions oftest peculiar to maintenance chemical type.10.1.3 All
34、oy type, surface treatment and condition, andnumber of specimens tested.10.1.4 Temperature, duration of test, and agitation if any.10.1.5 Average corrosion rate, R1, R2, R3, R4, or weight lossin milligrams per square centimetre per day for each specimenwhere:R5W/surface area of panel in cm2total exp
35、osure time of panel/2410.1.6 Range in weight losses.10.1.7 Effect of time on liquid corrosiveness and metalcorrodibility calculated in accordance with Annex A3.10.1.8 Appearance before and after removal of corrosionproducts with regard to the following:10.1.8.1 Discoloration and dulling,10.1.8.2 Etc
36、hing,10.1.8.3 Presence of accretions and relative amounts,10.1.8.4 Pitting, and10.1.8.5 Presence of selective or localized attack.11. Precision and Bias11.1 Committee F07 has no plans to establish a precisionand bias statement for this test method.12. Keywords12.1 aircraft metals; corrosion rates as
37、 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 deteriorationANNEXES(Mandatory Information)A1. CHEMICAL METHO
38、DS 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 includedin the weight loss determination
39、.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 materials.A1.1.2 Copper and Nickel
40、 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 been added,with agitation, 1 weig
41、ht % 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 %).F482033A1.1.5 Stainless SteelImmerse the specimen for 5 min ina solution of nitric acid (30 volume %) a
42、t 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 metalsand alloys listed in Table A2.1; other metals or alloys must beevaluated before use.A2.2 After scrubbing, remove loosely att
43、ached 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/dm3(6.5 A/0.325 dm3)Temperature
44、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 determination.A2.4 Note th
45、e possible redeposition of adherent metal fromreducible corrosion products (and thus lowering the apparentweight loss) resulting from this electrolytic treatment. How-ever, general experience has indicated that in most cases ofcorrosion in liquids, the possible errors from this source are notlikely
46、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.A3. CRITERIA FOR CORROSIVENESS OF ENVIRONMENT AND METAL CORRODIBILITYA3.1 The corrosion results obtained by this method pro-vides in
47、formation on the corrosiveness of the environment andthe corrodibility of the material under test in the environment.Therefore, R1is the initial corrosion rate of virgin metal perunit time, R5is the corrosion rate of metal per unit time afterlong exposure, and R4is the corrosion rate of virgin metal
48、 afterlong exposure of the corroding fluid to corroding metal. Thesignificance of these values can be appreciated by comparingthe corrosion rate R1for a unit time interval of 0 to 48 h withthe corrosion rate for the unit time interval of 120 to 168 h,which shows the magnitude and direction of change
49、 in corro-siveness of the environment that possibly has occurred duringthe total time of the test. Comparisons of R5, the corrosion rateof metal after long exposure, with R4, where R5is the corrosionrate calculated by substracting R2from R3, correspondinglyshows the magnitude and direction of change in the corrod-ibility of the metal specimen during the test. Therefore, takecomparisons of corrosion rates R1, R4, and R5for possiblechanges in corrosiveness of the environment and corrodibilityof the metal.A3.2 Table A3.1 is the criteria for all possible co
