1、Designation: B 810 01a (Reapproved 2006)Standard Test Method forCalibration of Atmospheric Corrosion Test Chambers byChange in Mass of Copper Coupons1This standard is issued under the fixed designation B 810; the number immediately following the designation indicates the year oforiginal adoption or,
2、 in the case of revision, the year 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 calibration of atmosphericcorrosion test chambers f
3、or electrical contacts that produce anadherent film of corrosion product on copper, such as a testcomprised of a mixture of flowing gases that react with copper.1.2 This test method is not applicable to tests wherecorrosion products may be removed from a copper surfaceduring the test by fluids.1.3 T
4、his test method is not applicable to tests whereairborne solid or liquid material may be deposited on a coppersurface during the test, as in a test which includes particulatessuspended in the atmosphere.1.4 The values stated in SI units are to be regarded as thestandard.1.5 This standard does not pu
5、rport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to become familiarwith all hazards including those identified in the appropriateMaterial Safety Data Sheet (MSDS) for this product/materialas provided by the manufacturer
6、, to establish appropriatesafety and health practices, and determine the applicability ofregulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2B 845 Guide for Mixed Flowing Gas (MFG) Tests forElectrical Contacts3. Summary of Test Method3.1 Copper coupon samples of a well-def
7、ined size areprepared and each is labeled for identification. All suchcoupons are cleaned by a standard process. Each coupon isweighed and the value is recorded. All coupons are exposed tothe corrosion test for a specified time. The coupons areremoved from the test and weighed and the new values are
8、recorded. The change in weight for each coupon is calculated.The coupons are subjected to additional analysis as appropriateto determine the composition and thickness of any filmspresent on the surface.4. Significance and Use4.1 Electrical devices that contain electrical contacts gener-ally contain
9、some copper-based materials. Atmospheric corro-sion of copper parts in such devices often occurs in serviceenvironments. A quantitative measure of the effect of alaboratory corrosion test on copper permits assessment of theseverity of the test. In addition, corrosion tests may be definedin terms of
10、their effect on copper; this test method provides away of comparing one test against a standard defined else-where, or allows a comparison of the performance of a testover a period of time. Although this test method provides for arelatively simple check of a test, the user is advised thatadditional
11、analysis of the test chamber ambient is generallyrequired to reproduce test conditions.4.2 Atmospheric corrosion tests are used on a variety ofmaterials besides copper. Care should be exercised in drawingconclusions about the effects on such materials of apparentlyequivalent tests if the composition
12、 of gases or experimentalconditions are different. The primary use of this calibration testmethod is to assure correlation among nominally identicaltests.5. Apparatus5.1 Racks or Fixtures suitable for holding the copper cou-pons in the test chamber are required. Make these fixtures froma material th
13、at is not attacked by the corrosion test. The fixturesshall be designed to:5.1.1 Hold the coupons in a vertical orientation,5.1.2 Hold the coupons so that they do not show anyperceptible motion when observed with the unaided eye duringthe test,1This test method is under the jurisdiction of ASTM Comm
14、ittee B02 onNonferrous Metals and Alloys and is the direct responsibility of SubcommitteeB02.11 on Electrical Contact Test Methods.Current edition approved Dec. 1, 2006. Published December 2006. Originallyapproved in 1991. Last previous edition approved in 2001 as B 810 01a.2For referenced ASTM stan
15、dards, 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken,
16、PA 19428-2959, United States.5.1.3 Cover less than 5 % of the entire coupon surface area,5.1.4 Touch the coupon only with electrically insulatingparts and,5.1.5 Allow free circulation of the ambient on both sides ofthe coupon.5.2 In general, design all parts of the fixture to permitmaximum circulati
17、on of the ambient around the couponsurfaces. The size and positioning of the holding fixturesdepends on the chamber size. Section 6 of this test methodgives requirements on the number and spacing of coupons; theholding fixtures must be designed to comply with theserequirements.5.3 Balance, with a ca
18、pacity of at least 2 g and a resolutionof 5 g is required. Maintain the ambient in the vicinity of thebalance between 20 and 50 % relative humidity.5.4 Fume Hood, to conduct the chemical cleaning procedureof the coupons is required.6. Reagents and Materials6.1 Purity of ReagentsReagent grade chemica
19、ls shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society3where such specifications are available. Other grades may beused, provided it is first ascertained that the
20、reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.7. Procedure7.1 Use the requirements listed in 7.1.1 through 7.1.3 todetermine the number of copper coupon specimens to beprepared.7.1.1 For chambers with cubic working volumes, use thelength o
21、f an edge to determine the number and placement ofcoupons in accordance with the following rules. For chamberswith an edge dimension of 0.9 m or less, construct a referencegrid with three equally spaced lines in each direction with theouter lines 0.1 m from the chamber wall and the third linecentere
22、d between the outer lines. Place a coupon at eachintersection of grid lines (27 coupons required). For chamberswith an edge dimension of 0.9 m to 1.4 m, construct a referencegrid with four equally spaced lines in each direction. The outerlines are placed 0.1 m from the chamber wall. Place a couponat
23、 each intersection of grid lines (64 coupons required). Forchambers with a maximum edge dimension greater than 1.4 mbut less than 2.0 m, construct a reference grid with five equallyspaced lines in each direction. The outer lines are placed 0.1 mfrom the chamber wall. Place a coupon at each intersect
24、ion ofgrid lines (125 coupons required).7.1.2 For rectangular chambers with non-cubic workingvolumes, the guidelines for each dimension of the chamberalong the x, y, and z axes of the chamber shall follow theappropriate guidelines applied to cubic chambers. Thus, if thex and z axes are 1.5 m and the
25、 y axis is 0.8 m, four grid lineswould be used for the x and z axes and 3 grid lines would beused for the y axis when determining the grid for couponlocation.7.1.3 For chambers with working volumes of other shapesthan those covered in the preceding sections, devise a logicalplacement pattern with a
26、coupon density roughly equal to thatspecified for rectangular chambers.7.2 Select an appropriate duration of exposure for thecopper coupons. Base this selection primarily upon the timerequired for the test ambient to produce a statistically signifi-cant weight change. Additional exposure time may be
27、 added tocomply with other applicable requirements, specifications,agreements, etc., or for the convenience of the test operators, orboth. Generally, the test time shall be one or more whole dayswith a tolerance of 61h.7.3 Prepare the test coupons from wrought, annealed,oxygen-free copper (99.95 % c
28、opper minimum, copper alloyC10200) sheet. Select a thickness of sheet sufficiently stiff toresist bending during handling during the test but not so thickthat the edges become a significant portion of the surface area.In general, thicknesses between 0.1 and 0.6 mm are recom-mended. Obtain material w
29、ith a surface roughness less than0.15 m center line average and use the material with theas-rolled surface finish. Make the coupons, squares or rect-angles preferably 12.5 6 1.2 mm wide. One or two holes 2.5mm or less in diameter may be added to aid in mounting.Inspect the edges of the coupons at 10
30、3 magnification for thepresence of burrs or slivers. If such features are found, theymust be removed since they may corrode at a much higher ratethan the coupon surface.7.4 Mark all coupons with a code giving each coupon aunique identification. Make the characters in the code markingabout 2 mm high
31、by engraving or stamping without ink.7.5 During the cleaning procedure and at all times aftercleaning, handle coupons only with clean tweezers grasping inthe region around the identification marking. Place each coppercoupon in a separate clean, dry glass vial of an appropriate sizesuch that only the
32、 edges and corners of the coupons touch theglass surfaces.7.6 Clean all coupons in accordance with either of the twoprocedures given in 7.6.1 through 7.6.2.5. Where a liquid bathis required, fill an appropriate vessel to a depth equal to orgreater than 25 mm plus the largest dimension of the coupons
33、ample to be cleaned. Unless otherwise directed, change thefluid in all baths after 50 coupons have been processed. Unlessotherwise directed, use all baths at room temperature.(WarningConduct all operations involving acids and sol-vents in a fume hood. Please be careful of N-Hexane. It isextremely fl
34、ammable.)(WarningDispose of all acids andsolvents in a safe, legally acceptable manner.)NOTE 1The goal of Cleaning Methods 1 and 2 are to produce acoupon surface reasonably free of oils, greases, particulate debris andoxides. Alternative cleaning methods which achieve the same result areacceptable.
35、See the Appendix X1 for an example of comparison cleaningmethod research. Such alternative cleaning methods may be necessary ordesirable depending upon local conditions or facilities.3Reagent Chemicals, American Chemical Society Specifications , AmericanChemical Society, Washington, DC. For suggesti
36、ons on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.B 810 01a (2006)27.6.1 Cleaning
37、Method 1:7.6.1.1 Immerse a coupon or small group of coupons for 5to 10 minutes in an ultrasonic cleaner containing hot (65 to85C) 2 % aqueous solution of a mildly alkaline (pH7.510)detergent.7.6.1.2 Remove an individual coupon from the cleaner andrinse under warm running tap water for 5-15 seconds.
38、Transferto the next step immediately.7.6.1.3 Transfer the coupon into a solution of 1 part con-centrated hydrochloric acid and 3 parts deionized water;suspend coupon vertically for 120 6 10 s in this solution.7.6.1.4 Transfer the coupon immediately without allowingdrying of surface into one of the f
39、ollowing treatments: suspendcoupon vertically in flowing deionized water for 15 6 5sor,suspend coupon with agitation for 15 6 5 s in one vessel ofdeionized water, then immediately repeat in a second vessel offresh deionized water.7.6.1.5 Transfer the coupon immediately without allowingdrying of surf
40、ace to a bath of methanol; suspend the couponvertically for 30 to 60 s with agitation in the bath.7.6.1.6 Remove the coupon from methanol, immediatelyblow dry with prepurified nitrogen or with clean, dry air.7.6.1.7 Place the coupon immediately in its glass vial, leavevial uncapped for 10 min, then
41、cap vial unless proceedingimmediately to the next step.7.6.2 Cleaning Method 2:7.6.2.1 Immerse the coupon to be cleaned in n-Hexane for120 s. Allow to drip dry for 10 s.7.6.2.2 Immerse the coupon in Alphametals Lonco flux335511 or equivalent material for 15 s. Allow to drip dry for10 s.7.6.2.3 Rinse
42、 the coupon twice with deionized water for15 s.7.6.2.4 Rinse coupon in methanol for 15 s and then allow todry.7.6.2.5 Place the coupon immediately in its glass vial, leavevial uncapped for 10 min, then cap vial unless proceedingimmediately to the next step.7.7 Allow all copper coupons to equilibrate
43、 in the vicinity ofthe balance for at least 30 min by placing the vials containingthe coupons near the balance and removing the cap from eachvial. Also, wait long enough so that at least 60 min has elapsedfrom the time that cleaning procedure was completed until theweighing begins. Weigh each coupon
44、 individually, replacingeach in its glass vial after weighing. Reweigh two of thecoupons to check for reproducibility. If the second weightreading does not differ by more than 1.0 g/cm2of exposedsurface area, proceed to the next step. If the readings differ bymore than the preceding requirement, rew
45、eigh all coupons andrepeat as required until stable weights are obtained.7.8 Immediately install all coupons on holding fixtures inthe corrosion test chamber. Record the time that the couponsare placed into the corrosion test.7.9 After the appropriate test time for the test method in usehas elapsed,
46、 remove the coupons from the holding fixture,placing each in an uncapped vial. Place the vials containing thecoupons in the vicinity of the balance and wait at least 30 minto allow the coupons to come to equilibrium with roomtemperature and humidity.7.10 Weigh all coupons, reweigh each coupon as req
47、uireduntil a stable reading is obtained for each coupon.7.11 Calculate the difference in weight before and afterexposure to the corrosion test.8. Report8.1 Report the results in the data report format shown inFig. 1.9. Precision and Bias9.1 PrecisionAn interlaboratory round robin involvingsix labora
48、tories produced the following results. Each labora-tory prepared 8 or 12 coupons by the procedures specified inthis standard. All coupons from all laboratories were exposedsimultaneously for 10 days to a Guide B 845 Method G testenvironment. The mass gain on each coupon (exposed area of7.8 cm2) was
49、measured, Table 1 summarizes the results. Theresults show that the minimum mass change within a labora-tory ranges from 56 to 71 percent of the maximum masschange for that laboratory, while, in comparing the mean masschanges for the six laboratories, the minimum is 93 percent ofthe maximum. Based on analysis of trends in mass gain withlocation, it appears that some of the difference in mass gainbetween coupons from a single laboratory came from differ-ences in corrosion rate in different locations within the testchamber.9.2 BiasThe procedure in this test method for calibr
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