Designation:A90/A90M−13
Standard Test Method for
Weight[Mass]of Coating on Iron and Steel Articles with Zinc or Zinc-Alloy Coatings1
This standard is issued under thefixed designation A90/A90M;the number immediately following the designation indicates the year of original adoption or,in the ca of revision,the year of last revision.A number in parenthes indicates the year of last reapproval.
A superscript epsilon(´)indicates an editorial change since the last revision or reapproval.
This standard has been approved for u by agencies of the Department of Defen.
1.Scope*
1.1This test method covers procedures for determining the weight[mass]of coating on iron or steel sheet,wire,and other articles in which the coating is zinc or a zinc alloy,such as zinc-5%aluminum(including zinc-5%aluminum-mischmetal and zinc-5%aluminum-0.1%magnesium),zinc-aluminum-magnesium(including zinc-5to9%aluminum-magnesium and zinc-9to13%aluminum-magnesium)or55% aluminum-zinc.In the body of this test method,reference to zinc coating shall be interpreted to also include zinc alloy coating except where specifically stated otherwi.
1.2Thefinal results determined by this test method shall be expresd in inch-pound units or SI units,depending on the units ud in the material specification to which the results are to be compared.Certain portions of the procedure involving determination of specimen weight[mass]have traditionally been performed in SI units,and corresponding inch-pound units are not included.
1.3For sheet products,thefinal results are expresd as either coating weight[mass]total both sides,or coating weight [mass]parately on each side,depending on the specified requirements.
1.4This standard does not purport to address all of the safety concerns,if any,associated with its u.It is the responsibility of the ur of this standard to establish appro-priate safety and health prac
tices and determine the applica-bility of regulatory limitations prior to u.For specific hazards statements e5.1.
2.Referenced Documents
2.1ASTM Standards:2
A653/A653M Specification for Steel Sheet,Zinc-Coated (Galvanized)or Zinc-Iron Alloy-Coated(Galvannealed) by the Hot-Dip Process
A792/A792M Specification for Steel Sheet,55% Aluminum-Zinc Alloy-Coated by the Hot-Dip Process
A875/A875M Specification for Steel Sheet,Zinc-5%Alu-minum Alloy-Coated by the Hot-Dip Process
A1046/A1046M Specification for Steel Sheet,Zinc-Aluminum-Magnesium Alloy-Coated by the Hot-Dip Pro-cess
A1057/A1057M Specification for Steel,Structural Tubing, Cold Formed,Welded,Carbon,Zinc-Coated(Galvanized) by the Hot-Dip Process
A1063/A1063M Specification for Steel Sheet,Twin-Roll Cast,Zinc-Coated(Galvanized)by the Hot-Dip Process A1079Specification for Steel Sheet,Complex Pha(CP), Dual Pha(DP)and Transformation Induced Plasticity (TRIP),Zinc-Coated(Galvanized)or Zinc-Iron Alloy-Coated(Galvannealed)by the Hot-Dip Process
D1193Specification for Reagent Water
E29Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
3.Significance and U
发红包的吉利数字
3.1This test method provides a standard method for deter-mining the weight[mass]of coating for comparison with specification requirements.A coating of zinc on iron or steel articles provides protection against corrosion.As the protection is provided by sacrificial loss of zinc,the degree of protection is proportional to the weight[mass]of zinc coating.Specifi-cations for zinc-coated articles frequently provide for different class of coating so that the purchar can lect the coating weight[mass]most suitable to his needs.
1This test method is under the jurisdiction of ASTM Committee A05on Metallic-Coated Iron and Steel Products and is the direct responsibility of
Subcommittee A05.07on Methods of Testing.
Current edition approved April1,2013.Published April2013.Originally approved in1923.Last previous edition approved in2011as A90/A90M-11.DOI: 10.1520/A0090_A0090M-13.
2For referenced ASTM standards,visit the ASTM website,www.astm,or contact ASTM Customer Service at rvice@astm.For Annual Book of ASTM Standards volume information,refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes ction appears at the end of this standard Copyright©ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA19428-2959.United States
4.Reagents
4.1Purity of Reagents—Reagent grade chemicals shall be ud in all tests.Unless otherwi indicated,it is intended that all reagents shall conform to the specifications of the Commit-tee on Anal
ytical Reagents of the American Chemical Society,where such specifications are available.3Other grades may be ud,provided it is first ascertained that the reagent is of sufficiently high purity to permit its u without lesning the accuracy of the determination.
4.2Purity of Water—Water ud to prepare chemical solu-tions shall be reagent water as defined by Type IV of Specification D1193.
4.3Antimony Trichloride Solution—Dissolve 20g of Sb 2O 3or 32g of SbCl 3in 1000mL of HCl (sp gr 1.18to 1.19).4.4Hydrochloric Acid (sp gr 1.18to 1.19)—Concentrated hydrochloric acid (HCl).
4.5Hydrochloric Acid—Antimony Trichloride Solution—Add 5mL of antimony trichloride solution to 100mL of HCl (sp gr 1.18to 1.19).
安慰的英文
4.6Hydrochloric Acid (1+1)—Mix 500mL of HCl (sp gr 1.18to 1.19)with 500mL of reagent water and cool to room temperature.
4.7Sulfuric Acid (25+75)—Mix 250mL of H 2SO 4(sp gr 1.84)with 750mL of reagent water and cool to room temperature.
N OTE 1—It is advisable to u an inhibitor with acid solution (for example,Hexamethylamine Tetram
ine or similar)at the concentration level according to the manufacturer’s recommendations to prevent attack of the substrate.
5.Hazards
5.1Warning—Small amounts of the poisonous gas stibine (SbH 3)may be evolved during the stripping process using the hydrochloric acid-antimony trichloride method.Hydrochloric acid fumes are prent,and hydrogen gas is evolved in the stripping process.Therefore,the test should be performed under conditions of adequate ventilation.A fume hood is recommended for large numbers of samples or where the test is to be carried out frequently over extended periods of time.5.2Warning—Mixing of sulfuric acid with water could result in vere injuries if not properly done.Mixing must be done by slowly adding sulfuric acid to water due to the heat generated and possible splashing.Under no circumstances should the water be added to the acid.The mixing should be performed under an acid fume hood.
6.Sampling
6.1Zinc-Coated Sheets—Samples for weight [mass]of coating determination shall be cured in accordance with Specifications A653/A653M ,A792/A792M ,A875/A875M ,
A1046/A1046M ,A1057/A1057M ,A1063/A1063M ,or A1079depending on the type of coating.
N OTE 2—For convenience in calculating test results in inch-pound units,the specimen should have an area of 5.08in.2of sheet (2.2560.01-in.square or 2.5460.01in.in diameter).The weight [mass]of coating in grams on a specimen of that area is numerically equal to the weight [mass]of coating in ounces per square foot of sheet.For results to be reported in metric units,the specimen should have an area of 3330mm 2of sheet (57.760.1-mm square or 65.160.1mm in diameter).
6.2Zinc-Coated Wire—Samples shall be cured as desig-nated in the appropriate specification.The specimen of wire may be of any length over 12in.[305mm],but preferably about 24in.[609mm].Where a continuous length is not available,shorter lengths totaling over 12in.[300mm],but preferably about 24in.[600mm],shall be ud.Since the density of the steel is known 0.283lb/in.3[7830kg/m 3],it is not necessary to u a specific length of specimen.
6.3Zinc-Coated Articles Other Than Sheet or Wire—Samples for weight [mass]of coating determination shall be cured as designated in the appropriate specification.Except as otherwi provided,the specimens should have a minimum area of 3in.2(2000mm 2)of zinc-coated surface.For very small items,veral pieces may have to be stripped to obtain the minimum area.
6.3.1In the ca of threaded articles,such as bolts and screws,the determination shall be made on a portion of the articles that does not include any thread.
7.Procedure
7.1Strip the zinc coating from the specimens by using one of the following methods:hydrochloric acid (1+1),hydro-chloric acid-antimony trichloride solution,or sulfuric acid (25+75).For zinc alloy coatings containing less than 90%zinc,the stripping shall be done using hydrochloric acid (1+1)or sulfuric acid (25+75).
7.2Clean the specimens by washing with solvent naphtha or other suitable solvent,then rin with alcohol,and dry thor-oughly.
7.3Determine the weight [mass]of the specimens individu-ally to the nearest 0.01g,except for articles other than sheet or wire with a specimen weight [mass]greater than 125g,determine the weight [mass]to at least the nearest 0.1g.After determining the weight [mass],immer each specimen singly in the stripping solution and allow to remain until the violent evolution of hydrogen has cead,and only a few bubbles are being evolved.This requires about 15to 30s,except in the ca of sherardized coatings,which require a somewhat longer time.The same solution may be ud repeate
dly until the time required for stripping becomes inconveniently long.The tem-perature of the stripping solution shall at no time exceed 100°F [38°C].After stripping,wash the specimens by scrubbing them under running water,dip in hot water,and wipe or blow dry.Determine the weight [mass]of the specimens again,to the same precision as in the initial determination.
7.4Sheet Specimens—When measuring the total coating weight [mass]on both sides,or the single side coating weight [mass]on each side,determine the area of sheet (one surface)
3
“Reagent Chemicals,American Chemical Society Specifications,”Am.Chemi-cal Soc.,Washington,DC.For suggestions on the testing of reagents not listed by the American Chemical Society,e “Analar Standards for Laboratory U.K.Chemicals,”BDH Ltd.,Poole,Dort,and the “United States
Pharmacopeia.”
to the nearest0.01in.2[5mm2].If specimens were prepared to the dimensions as provided in Note2,they shall be presumed to have an area of5.08in.2[3330mm2].When it is not possible to deter
mine the area accurately,as in specimens from corru-gated sheets,the thickness of the stripped sheet shall be determined to the nearest0.001in.[0.01mm].
7.4.1When determining the coating weight[mass]on one side of sheet material,u the procedure described in7.3, except u a“stop-off”to protect one side from the stripping medium.Acid-resistant paints or lacquers,acid-resistant tape, or mechanical devices fastened to the test specimen are examples of commonly ud“stop-off”materials.Apply the “stop-off”to the specimen after the initial determination of weight[mass]and remove before the cond determination of weight[mass].Becau of the possibility of moisture absorp-tion during the stripping process,the“stop-off”must not be on the specimen during either weight[mass]determinations. Determine the coating weight[mass]on the cond side subquently without a“stop-off”on thefirst side.
7.5Wire Specimens—Determine the diameter of the stripped wire to the nearest0.001in.[0.01mm]by taking the average of two measurements at right angles to each other.
7.6Specimens Other Than Sheet or Wire—Determine the total coated area of the original specimen to the nearest0.01 in.2[5mm2].Alternatively,for specimens of uniform thickness of ba metal,such a
s a piece of plate or pipe,determine the average thickness of the stripped specimen to the nearest0.001 in.[0.01mm].
8.Calculation
8.1Zinc-Coated Sheet:
8.1.1Results in Inch-Pound Units:
8.1.1.1When the area of one surface of the sheet is determined,calculate the weight[mass]of coating as follows:
C5@~W12W2!/A#3K(1) where:
C=weight[mass]of coating,oz/ft2of sheet,
W1=original weight[mass]of specimen,g,
W2=weight[mass]of stripped specimen,g,
A=area of one surface of the sheet,in.2or mm2,and,
K=a constant=5.08when A is in in.2,or=3.28×103 when A is in mm2.
N OTE3—If the specimen was prepared to the dimensions as provided in Note2,having an area of5.08in.2,the loss of weight[mass]in grams is numerically equal to the weight[mass]of coating in ounces per square foot of sheet.香远溢清
8.1.1.2When it is not possible to cure a specimen of measurable area,calculate the weight[mass]of coating as follows:
C5@~W12W2!/W2#3T3K(2) where:
C=weight[mass]of coating,oz/ft2of sheet,
W1=original weight[mass]of specimen,g,
W2=weight[mass]of stripped specimen,g,
T=thickness of stripped mm,and K=a constant=652when T is in in.,or=25.7when T is in mm.
8.1.2Results in Metric Units:
8.1.2.1When the area of sheet is determined,calculate the weight[mass]of coating as follows:
C5@~W12W2!/A#3K(3) where:
C=weight[mass]of coating,g/m2of sheet,
W1=original weight[mass]of specimen,g,
W2=weight[mass]of stripped specimen,g,
A=area of one surface of the sheet,in.2or mm2,and
K=a constant=1.55×103when A is in in.2,or=1×106 when A is in mm2.
N OTE4—If the specimen was prepared to the dimensions as provided in Note2,having an area of3330mm2of sheet,the factor K/A is approximately300,which may be ud in the calculation.
澳大利亚季节8.1.2.2When it is not possible to obtain a specimen of measurable area,calculate the weight[mass]of coating as follows:
C5@~W12W2!/W2#3T3K(4) where:
C=weight[mass]of coating,g/m2of sheet
W1=original weight[mass]of the specimen,g,
W2=weight[mass]of the stripped specimen,g,
T=thickness of stripped mm,and
K=a constant=1.99×105when T is in in.,or=7.83×103when T is in mm.
8.2Zinc-Coated Wire:
8.2.1Results in Inch-Pound Units:
8.2.1.1Calculate the weight[mass]of zinc coating as follows:
C5@~W12W2!/W2#3D3M(5) where:
C=weight[mass]of coating,oz/ft2of stripped wire surface,
W1=original weight[mass]of specimen,g,
W2=weight[mass]of stripped specimen,g,
D=diameter of stripped mm,and
M=a constant=163when D is in in.,or=6.42when D is in mm.
8.2.2Results in Metric Units:
8.2.2.1Calculate the weight[mass]of zinc coating as follows:
C5@~W12W2!/W2#3D3M(6) where:
C=weight[mass]of coating,g/m2of stripped wire surface,
W1=original weight[mass]of specimen,g,
W2=weight[mass]of stripped specimen,g,
D=diameter of stripped mm,and
M=a constant=4.97×104when D is in in.,or=1.96×103when D is in mm.
8.3Zinc-Coated Articles Other Than Sheet or Wire:
8.3.1Results in Inch-Pound
Units:
8.3.1.1Calculate the weight[mass]of coating as follows:
C5@~W12W2!/A#3N(7) where:
C=weight[mass]of coating,oz/ft2of surface,
W1=original weight[mass]of specimen,g,
W2=weight[mass]of stripped specimen,g,
A=coated area of original specimen,in.2or mm2,and N=a constant=5.08when A is in in.2,or=3.28×103 when A is in mm2.
8.3.1.2If the specimen has a uniform thickness of ba metal,calculate the weight[mass]of coating as follows:
C5@~W12W2!/W2#3G3Z(8) where:
C=weight[mass]of coating,oz/ft2of surface,
W1=original weight[mass]of specimen,g,
W2=weight[mass]of stripped specimen,g,
G=thickness of stripped mm,and
Z=a constant=326when G is in in.,or12.8when G is in mm.
8.3.2Results in Metric Units:
8.3.2.1Calculate the weight[mass]of zinc coating as follows:
C5@~W12W2!/A#3N(9) where:
C=weight[mass]of coating,g/m2of surface,
W1=original weight[mass]of specimen,g,
W2=weight[mass]of stripped specimen,g,
A=coated area of original specimen,in.2or mm2,and N=a constant=1.55×103when A is in in.2,or=1×106 when A is in mm2.
8.3.2.2If the specimen has a uniform thickness of ba metal,calculate the weight[mass]of coating as follows:
C5@~W12W2!/W2#3G3Z(10) where:
C=weight[mass]of coating,g/m2of surface,
W1=original weight[mass]of specimen,g,
W2=weight[mass]of stripped specimen,g,
G=thickness of stripped mm,and
Z=a constant=9.95×104when G is in in.,or=3.92×103when G is in mm.
9.Report
9.1Weight[mass]of coating on zinc-coated sheet is ex-presd in weight[mass]per unit area of sheet,and is either the sum of the weights[mass]of coating on both sides of the sheet,or single side weight[mass]on each of the two sides. Weights[mass]of coating on each side of the sheet are not necessarily equal,even when both sides are expod to the molten metal or plating solution simultaneously.Coating weights[mass]on all zinc-coated articles other than sheets are expresd in weight[mass]per unit area of surface.
9.2Report the weight[mass]of zinc coating to the nearest 0.01oz/ft2when reporting in inch-pound units.
9.3Report the weight[mass]of zinc coating to the nearest 1g/m2when reporting in metric units.
9.4When the weight[mass]of coating of a number of specimens is to be averaged to determine conformance with a specification limit,the average value shall be reported to the precision described in9.2and9.3in accordance with the Rounding Method of Practice E29.
10.Precision and Bias
外国神话故事
10.1The precision of this test method is bad on an interlaboratory study conducted in2006.Each of ten laborato-ries tested three replicates of two different materials.4Data was recorded in inch-pound units only and should not be considered metric equivalents.See Table1for a statistical summary of the test results.
10.1.1Repeatability—Two test results obtained within one laboratory shall be judged not equivalent if they differ by more than the“r”value for that material;“r”is the interval reprenting the critical difference between two test results for the same material,obtained by the same operator using the same equipment on the same day in the same laboratory. 10.1.2Reproducibility—Two test results shall be judged not equivalent if they differ by more than the“R”value for that material;“R”is the interval reprenting the difference be-tween two test results for the same material,obtained by different operators using different equipment in different labo-ratories.
10.1.3Any judgment in accordance with the two state-ments would have an approximate95%probability of being correct.
10.2Bias—At the time of the study,there was no accepted reference material suitable for determining the bias for this test method,therefore no statement on bias is being made.
10.3The precision statement was determined through sta-tistical examination of three results,from ten laboratories,on two materials.
11.Keywords印度电影起跑线
11.155%aluminum-zinc alloy coating;coating weight [mass];steel sheet;steel wire;zinc alloy coatings;zinc coating;
4Supporting data have beenfiled at ASTM International Headquarters and may be obtained by requesting Rearch Report RR:A05-1003.
TABLE1Weight Mass Coating(in oz.ft2)
N OTE1—S
r means the standard deviation of r(repeatability).S
R
means the standard deviation for R(reproducibility).
陌陌含情
Material x¯S x¯S r S R r R
Hot Dipped Zinc-Coated Samples 1.1007800.0218950.0153330.0252220.0429330.070621 Electrolytic Zinc-Coated Samples0.4032210.0087900.0083780.0111380.0234570.031187
zinc-5%aluminum alloy coating;zinc-5%aluminum-0.1% magnesium alloy coating;zinc-5%aluminum-mischmetal al-loy coating;zinc-5to9%aluminum-magnesium alloy coating; zinc-9to13%aluminum-magnesium alloy coating
SUMMARY OF CHANGES
Committee A05has identified the location of lected changes to this standard since the last issue (A90/A90M-11)that may impact the u of this standard.(April1,2013)
(1)Added references to A1057/A1057M and A1079in2.1and
6.1.
ASTM International takes no position respecting the validity of any patent rights asrted in connection with any item mentioned in this standard.Urs of this standard are expressly advid that determination of the validity of any such patent rights,and the risk
of infringement of such rights,are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed everyfive years and if not revid,either reapproved or withdrawn.Your comments are invited either for revision of this standard or for additional standards
and should be addresd to ASTM International Headquarters.Your comments will receive careful consideration at a meeting of the
responsible technical committee,which you may attend.If you feel that your comments have not received a fair hearing you should
make your views known to the ASTM Committee on Standards,at the address shown below.
This standard is copyrighted by ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA19428-2959, United States.Individual reprints(single or multiple copies)of this standard may be obtained by contacting ASTM at the above
address or at610-832-9585(phone),610-832-9555(fax),or rvice@astm(e-mail);or through the ASTM website
坡道定点停车技巧(www.astm).Permission rights to photocopy the standard may also be cured from the ASTM website(www.astm/
COPYRIGHT/).
