1、Designation: E 1659 05Standard Test Methods forCoating Weight and Chemical Analysis of Zinc-Nickel AlloyElectrolytically Coated on Steel Sheet1This standard is issued under the fixed designation E 1659; the number immediately following the designation indicates the year oforiginal adoption or, in th
2、e 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 These test methods cover independently the chemicalanalysis of each surface of zinc-n
3、ickel alloy electrolyticallycoated on steel sheet. The coatings have chemical composi-tions within the following limits:Analyte Concentration RangeCoating Weight 0.0 to 80 g/m2Nickel 7.0 to 17.0 %1.2 These test methods are in the following sections:SectionsCoating Weight, by the Weigh-Strip-Weigh Me
4、thod(20.0 to 45.0 g/m2)10-20Nickel by the Atomic Absorption Method (11.0 to 13.5 %of Coating Weight Ranging from 20 to 45 g/m2)21-311.3 The values stated in SI units are to be regarded asstandard. In some cases, exceptions allowed in Practice E 380are also used.1.4 This standard does not purport to
5、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 applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A 917 Spec
6、ification for Steel Sheet, Coated by the Electro-lytic Process forApplications Requiring Designation of theCoating Mass on Each Surface (General Requirements)A 918 Specification for Steel Sheet, Zinc-Nickel AlloyCoated by the Electrolytic Process for Applications Re-quiring Designation of the Coatin
7、g Mass on Each SurfaceD 1193 Specification for Reagent WaterE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE50 Practices for Apparatus, Reagents, and Safety Precau-tions for Chemical Analysis of MetalsE 135 Terminology Relating to Analytical Chemist
8、ry forMetals, Ores, and Related MaterialsE 173 Practice for Conducting Interlaboratory Studies ofMethods for Chemical Analysis of Metals3E 380 Practice for Use of the International System of Units(SI) (the Modernized Metric System)3E 663 Practice for Flame Atomic Absorption AnalysisE 882 Guide for A
9、ccountability and Quality Control in theChemical Analysis LaboratoryE 1024 Guide for Chemical Analysis of Metals and MetalBearing Ores by Flame Atomic Absorption Spectropho-tometryE 1452 Practice for Preparation of Calibration Solutions forSpectrophotometric and for Spectroscopic Atomic Analy-sesE 1
10、601 Practice for Conducting an Interlaboratory Study toEvaluate the Performance of an Analytical Method3. Terminology3.1 For definitions of terms used in this test method, refer toTerminology E 135.4. Significance and Use4.1 These test methods for the chemical analysis of zinc-nickel alloy coating o
11、n sheet steel are primarily intended asreferee methods to test such materials for compliance withcompositional specifications such as found in SpecificationA 918, particularly those under the jurisdiction of ASTMCommittee A05 on Metallic-Coated Iron and Steel Products. Itis assumed that all who use
12、these test methods will be trainedanalysts capable of performing common laboratory proceduresskillfully and safely. It is expected that work will be performedin a properly equipped laboratory under appropriate qualitycontrol practices such as those described in Guide E 882.4.2 These test methods mus
13、t be applied twice, once to eachside of the specimen if coating weight and composition arerequired for both sides of a coated sheet. Two separatespecimens are required for this purpose.1These test methods are under the jurisdiction of ASTM Committee E01 onAnalytical Chemistry for Metals, Ores, and R
14、elated Materials and are the directresponsibility of Subcommittee E01.05 on Cu, Pb, Zn, Cd, Sn, Be, TheirAlloys, andRelated Metals.Current edition approved Oct. 1, 2005. Published November 2005. Originallyapproved in 1995. Last previous edition approved in 2000 as E 1659 00.2For 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.3Withdrawn.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Con
16、shohocken, PA 19428-2959, United States.5. Apparatus, Reagents, and Instrumental Practices5.1 ApparatusSpecialized apparatus requirements arelisted in the apparatus section in each individual test method.5.2 Reagents:5.2.1 Purity of ReagentsUnless otherwise indicated, allreagents used in these test
17、methods shall conform to theReagent Grade Specifications of the American Chemical Soci-ety.4Other chemicals may be used, provided it is first ascer-tained that they are of sufficiently high purity to permit theiruse without adversely affecting the expected performance ofthe determination, as indicat
18、ed in Section 30.5.2.2 Purity of WaterReferences to water shall be under-stood to mean reagent water as defined by Type II of Specifi-cation D 1193.5.3 Photometric PracticePhotometric practice prescribedin these test methods shall conform to Guide E 1024 andPractice E 1452.6. Safety Hazards6.1 For p
19、recautions to be observed in the use of certainreagents and equipment in these test methods, refer to PracticesE50.7. Sampling7.1 Zinc-Nickel Alloy Coated SheetsSamples for deter-mining weight and composition of coating shall be secured inaccordance with Specification A 917, which is referred to inS
20、pecification A 918. Test specimens shall be of squares withsides of 50 6 5 mm. One test specimen is required for eachside to be analyzed. The backside which is not to be analyzedshall be marked “X.”8. Interlaboratory Studies and Rounding CalculatedValues8.1 Calculated values shall be rounded to the
21、desired num-ber of places in accordance with the rounding method ofPractice E29.9. Interlaboratory Studies9.1 These test methods have been evaluated using PracticeE 173, except for the update in the stripping solution, 17.1,17.8, 20.1.2, 20.2, 31.1.1, and 31.2 as well as Table 1, Table 2,Table 3, an
22、d Table 4.WEIGHT OF COATING ON ZINC-NICKEL ALLOY-COATED SHEET BY WEIGH-STRIP-WEIGHMETHOD10. Scope10.1 This test method provides a procedure for determiningindependently the weight of coating on each surface ofzinc-nickel alloy-coated sheet steel, in coating masses from 20to 45 g/m2(Note 1).4Reagent
23、Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions 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 Nat
24、ional Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.TABLE 1 Statistical InformationComparison of StrippingSolutions on 20/20 MaterialTestMaterialOriginalStrippingSolution,g/m2ACurrentStrippingSolution,g/m2AIronStripped,g/m2BAdjustedCoatingWeight,g/m2C1 23.45 23.74 0.68 23.062 2
25、3.18 24.29 0.83 23.463 23.54 24.33 1.13 23.204 23.11 23.94 0.64 23.30Average 23.320 24.075 0.820 23.2552 Standard Deviations 0.415 0.568 0.445 0.337AResults obtained following the original test method with no adjustments for ironstripped.BIron stripped from base metal from 17.8, expressed in g/m2.CC
26、oating weight results obtained by using the current test method, adjusting forthe stripped iron.TABLE 2 Statistical InformationComparison of StrippingSolutions on 30/30 MaterialTestMaterialOriginalStrippingSolution,g/m2ACurrentStrippingSolution,g/m2AIronStripped,g/m2BAdjustedCoatingWeight,g/m2C1 35.
27、21 38.19 1.03 37.162 37.47 35.83 0.50 35.333 35.64 37.86 0.55 37.314 37.65 36.05 0.51 35.54Average 36.493 36.983 0.648 36.3432 Standard Deviations 2.494 2.429 0.512 2.074AResults obtained following the original test method with no adjustments for ironstripped.BIron stripped from base metal from 17.8
28、, expressed in g/m2.CCoating weight results obtained by using the current test method, adjusting forthe stripped iron.TABLE 3 Statistical InformationComparison of StrippingSolutions on 20/20 MaterialTest MaterialOriginal StrippingSolution, %NiCurrent StrippingSolution, %Ni1 11.25 11.382 11.20 11.303
29、 11.37 11.33Average 11.27 11.342 Standard Deviations 0.175 0.081E1659052NOTE 1The upper limit of the scope has been set at 45 g/m2becausetest materials with higher coating weight were not available for testing inaccordance with Practice E 173. However, recognizing the simplicity ofthe weigh-strip-we
30、igh technique, materials with higher coating weightscan be tested following this procedure. Users of this test method arecautioned that use of it for coating weight determinations above 45 g/m2is not supported by interlaboratory testing.11. Summary of Test Method11.1 The coating on the sheet steel i
31、s stripped by usinghydrochloric acid solution containing an inhibitor to preventthe attack on the base steel. The coating weight is determinedfrom the weight difference of the specimen before and afterstripping.12. Interferences12.1 The hexamethylene tetramine inhibitor used in this testmethod permi
32、ts the dissolution of some base metal, whichcould lead to higher than expected coating weight determina-tions. Since Zn/Ni coatings contain no appreciable amounts ofFe, the effects of this bias are corrected by determining themass of iron stripped with the coating and subtracting thatvalue from the
33、raw weigh-strip-weigh data.13. Apparatus13.1 Analytical Balance, capable of weighing to 0.1 mg.13.2 Electroplaters Tape, capable of protecting one side ofa coated piece of sheet steel while the other side is beingstripped in a hydrochloric acid solution. It must not contami-nate the acid solution or
34、 interfere with the coating weightdetermination by gaining or losing weight.13.3 Vernier Calipers, calibrated to an international stan-dard and capable of measuring to at least 0.05 mm.14. Reagents14.1 Hexamethylene Tetramine, USP GradeUsed as aninhibitor to prevent acid attack of the base metal whi
35、lestripping the coating from the base steel.14.2 Stripping SolutionAdd 340 mL hydrochloric acid to1660 mL of water.Add 7.0 g of hexamethylene tetramine, mix,and cool before use.15. Precautions15.1 WarningHydrogen gas, which can form explosivemixtures with air, is evolved in the stripping process. Th
36、ere-fore, this test method should be performed under conditions ofadequate ventilation, such as a fume hood.16. Sample Preparation16.1 Clean the specimens with acetone using a soft papertowel, then dry with oil-free compressed air.16.2 Cover the side of the specimen from which the coatingis not to b
37、e stripped with electroplaters tape.16.3 Use a roller to press the tape firmly against the sheet,making sure to remove all air bubbles or wrinkles.16.4 Trim off the excess tape.16.5 Press the tape firmly near the edge to protect the tapedside from acid attack.16.6 Write the sample identification on
38、the taped side witha marker.17. Procedure17.1 Specimen AreaUsing the calipers, measure andrecord the length of all four sides of the test specimen.17.1.1 Check that the measuring face and reference edge ofthe calipers are clean. Check that the calipers read “0” whenthe measuring surface is closed. I
39、f it does not, correct theproblem according to the manufacturers instructions.17.1.2 Place the calipers at the corners of the specimen andmeasure the length of each side to the nearest 0.005cm.17.1.3 Record the length of each side as shown in thediagram below.NOTE 2To ensure that the calculated area
40、 is accurate even if thespecimen does not have 90 angles, all four sides are measured. In 18.2,the average of opposite sides is calculated and used to determine specimenarea.17.2 Weigh the prepared specimen to the nearest 0.1 mg andrecord the weight as the original weight of the specimen.17.3 Place
41、the sample in a 600-mL beaker with the tapedside down.17.4 Add 25 mL of stripping solution slowly. As the coatingis stripped, the color changes from gray to black and back togray (see Note 3).NOTE 3Stripping time will depend on the nickel composition andweight of the coating.17.5 After the coating i
42、s stripped, remove the sample with apoly (tetrafluoroethylene) coated magnet attached to one end ofan approximately 150-mm long flexible polyethylene tube.Holding it over the same beaker, rinse it carefully with waterand police the stripped side to remove the last traces of nickel.17.6 Dry the strip
43、ped specimen with oil-free compressedair. Weigh it to the nearest 0.1 mg and record the weight.17.7 Warm the beaker on a hotplate until all the strippedcoating is dissolved. Transfer the solution to a 100-mL volu-metric flask, dilute to the mark, and mix thoroughly. Reservethis sample stock solution
44、 for iron determination.TABLE 4 Statistical InformationComparison of StrippingSolutions on 30/30 MaterialTest MaterialOriginal StrippingSolution, %NiCurrent StrippingSolution, %Ni1 11.44 11.742 11.40 11.763 11.42 11.684 11.20 11.85Average 11.37 11.762 Standard Deviations 0.222 0.141E165905317.8 Dete
45、rmination of Stripped Iron:17.8.1 Calibrate the instrument in accordance with themanufacturers instructions following the guidelines set forthin Guide E 1024 and Practice E 1452. Choose the appropriatewavelength and calibration solutions that provide a calibrationcurve that includes up to 2.0 mg Fe/
46、100 mL of solution.17.8.2 Verify the calibration curve with an iron controlsolution that falls in the mid-range of the calibration curve. Ifthis control standard is not within 610 % of its assumed truevalue, identify the problem, recalibrate, and verify the curve. Ifthe control standard is within 61
47、0 %, analyze the solutionsfrom 17.7 for iron.17.8.3 After the final sample stock solution is analyzed, readthe iron control standard and check that the reading is within610 % of the assumed true value. If it is not, identify theproblem and repeat 17.8.1-17.8.3. If it is within 610 %, recordthe resul
48、ts of all sample solutions.NOTE 4The typical amount of iron stripped from the base steel whenperforming this test method is equivalent to a coating weight of about 1g/m2. Paragraph 17.8 allows a 10 % error in this Fe determination, whichis equal to a coating weight of 0.1 g/m2. On a sample with the
49、minimumcoating weight of 20 g/m2, this is an error in the coating weightdetermination of 0.5 %.At higher coating weights, the percent error woulddecrease. The reproducibility of the test method by Practice E 173 at acoating weight of 20 g/m2is 1.56 g/m2, or an error of 7.8 %. The error inthe iron determination was considered statistically insignificant andtherefore Paragraph 17.8 did not undergo a formal interlaboratory evalu-ation of precision and bias.18. Calculation18.1 Calculate the mass of the zinc-nickel alloy coating asfollows:M 5 W1 W2! E/1000!# (1
