1、Designation: A153/A153M 09A153/A153M 16 American Association State Highwayand Transportation Officials StandardAASHTO No. M232Standard Specification forZinc Coating (Hot-Dip) on Iron and Steel Hardware1This standard is issued under the fixed designation A153/A153M; the number immediately following t
2、he designation indicates the yearof original adoption or, in the case of revision, the year of last revision. A number in parentheses 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
3、 use by agencies of the U.S. Department of Defense.1. Scope*1.1 This specification covers zinc coatings applied by the hot-dip process on iron and steel hardware. The hot-dip galvanizingprocess consists of parts being immersed in molten zinc for a sufficient time to allow a metallurgical reaction be
4、tween iron fromthe steel surface and the molten zinc, resulting in the formation of Zn/Fe alloy layers bonding the coating to the steel surface.1.2 This specification is intended to be applicable to hardware items that are centrifuged or otherwise handled to remove excessgalvanizing bath metal (free
5、 zinc). Coating thickness grade requirements reflect this.1.3 This specification is applicable to orders in either inch-pound units (as A153) or in SI units (as A153M). Inch-pound unitsand SI units are not necessarily exact equivalents. Within the text of this specification and where appropriate, SI
6、 units are shownin brackets. Each system shall be used independently of the other without combining values in any way. In the case of orders inSI units, all testing and inspection shall be done using the metric equivalent of the test or inspection method as appropriate. In thecase of orders in SI un
7、its, such shall be stated to the galvanizer when the order is placed.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the
8、applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A90/A90M Test Method for Weight Mass of Coating on Iron and Steel Articles with Zinc or Zinc-Alloy CoatingsA143/A143M Practice for Safeguarding Against Embrittlement of Hot-Dip Galvanized Structural Steel
9、Products and Procedurefor Detecting EmbrittlementA780 Practice for Repair of Damaged and Uncoated Areas of Hot-Dip Galvanized CoatingsA902 Terminology Relating to Metallic Coated Steel ProductsB6 Specification for ZincB487 Test Method for Measurement of Metal and Oxide Coating Thickness by Microscop
10、ical Examination of Cross SectionB960 Specification for Prime Western Grade-Recycled (PWG-R) ZincE376 Practice for Measuring Coating Thickness by Magnetic-Field or Eddy-Current (Electromagnetic) Testing MethodsF1470 Practice for Fastener Sampling for Specified Mechanical Properties and Performance I
11、nspectionF1789 Terminology for F16 Mechanical Fasteners3. Terminology3.1 Definitions:3.1.1 The following terms and definitions are specific to this specification. Terminology A902 contains other terms anddefinitions relating to metallic-coated steel products. Terminology F1789 contains other terms a
12、nd definitions relating tomechanical fasteners.3.2 Definitions of Terms Specific to This Standard:1 This specification is under the jurisdiction ofASTM Committee A05 on Metallic-Coated Iron and Steel Products and is the direct responsibility of Subcommittee A05.13on Structural Shapes and Hardware Sp
13、ecifications.Current edition approved May 1, 2009Feb. 1, 2016. Published May 2009February 2016. Originally approved in 1933. Last previous edition approved in 20052009 asA153/A153M - 05.A153/A153M - 09. DOI: 10.1520/A0153_A0153M-09.10.1520/A0153_A0153M-16.2 For referencedASTM standards, visit theAST
14、M website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an ind
15、ication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be
16、considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.1 average coating thickness, nthe average of the specimen coating thickness values f
17、or the samples in an inspection lot.3.2.2 bare spots, nuncoated areas on the surface of the steel part that contain no measurable zinc coating.3.2.3 dross inclusions, nthe iron/zinc intermetallics present in a galvanized coating in a form other than the layer growth ofthe coating.3.2.4 individual me
18、asurement, nthe reading from a magnetic thickness gauge of a single coating spot thickness, or themicroscopic reading of a coating thickness as seen in an optical microscope at one spot.3.2.5 inspection lot, nthe quantity of identical parts cleaned, fluxed and galvanized together at one time in an a
19、ppropriatecontainer that is being submitted for acceptance as a group.3.2.6 malleable casting, na steel article that has been subjected to a prolonged anneal to decarburize or graphitize the part toremove as much of the carbon as possible or to convert the carbon to graphite, which permits plastic d
20、eformation in compressionwithout rupture.3.2.7 sample, na collection of individual units of product from a single inspection lot selected in accordance with Section 6and intended to represent that inspection lot for acceptance.3.2.8 specimen, nan individual test article upon which thickness measurem
21、ents or weight determinations are performed.3.2.9 specimen coating thickness, nthe average thickness from no less than five test measurements on a specimen, when eachmeasurement location is selected to provide the widest dispersion (in all applicable directions) of locations within the specimenvolum
22、e.3.2.10 threaded areas, nthe sections of a steel part that have threads formed before hot-dip galvanizing.4. Materials and Manufacture4.1 Steel or IronFerrous articles to be hot-dip zinc coated shall conform to specifications designated by the purchaser.4.2 ZincThe zinc used for the coating shall c
23、onform to Specification B6, or Specification B960, or both, and shall be at leastequal to the grade designated as “Prime Western.”4.2.1 If a zinc alloy is used as the primary feed for the galvanizing bath, then the base material used to make that alloy shallconform to Specification B6 or Specificati
24、on B960, or both.4.2.2 The molten metal in the working volume of the galvanizing bath shall contain not less than an average value of 98.0 %zinc by weight mass.NOTE 1The galvanizer may choose to add trace amounts of certain elements (for example, aluminum, nickel, bismuth, or tin) to the zinc bath t
25、o helpin the processing of certain reactive steels or to enhance the cosmetic appearance of the finished product. The elements can be added to the galvanizingbath as a master feed alloy, or they can be added to the bath by the galvanizer as individual feeds.4.3 Minimum Coating Weight Mass or Minimum
26、 Coating ThicknessThe minimum coating weight mass or the minimumcoating thickness shall conform to the requirements prescribed in Table 1 for the material category and thickness of material inwhich the article belongs.4.4 Threaded ArticlesThe zinc coating on threads shall not be subjected to a cutti
27、ng, rolling, or finishing-tool operation, unlessspecifically authorized by the purchaser. In order to meet overtapping allowances, tapping the threads of nuts or tapped holes aftergalvanizing is not prohibited.4.5 Touch-up and RepairBare spots that are found on parts after galvanizing shall be renov
28、ated by use of the methods foundin Practice A780 if the following criteria are met. The bare spots shall have an area totalling not more than 1 % of the surface areato be coated excluding threaded areas of the piece and the bare spots shall not include any threaded areas of the piece.The thicknessof
29、 the repair shall be equal to the surrounding galvanized coating except for repairs made by paints containing zinc dust in whichcase the thickness of the repair shall be 50 % greater than the thickness of the galvanized coating required for the class of material,but shall not be greater than 4.0 mil
30、s 100 m. Repair thickness measurements shall be made in accordance with Practice A780.The galvanizer shall make repairs unless directed by the purchaser to deliver items unrepaired for subsequent renovation by thepurchaser.5. Workmanship, Finish, and Appearance5.1 The zinc-coated articles shall be f
31、ree from uncoated areas, blisters, flux deposits, dross inclusions, and other types ofprojections that would interfere with the intended use of the articles, or other defects not consistent with good galvanizing practice.5.2 The zinc coating shall be reasonably smooth and reasonably uniform in thick
32、ness.NOTE 2Smoothness of surface is a relative term. Minor roughness that does not interfere with the intended use of the part, or roughness that is relatedto the as-received (ungalvanized) surface condition of the part, shall not be grounds for rejection.NOTE 3Since this specification is applicable
33、 to items that are centrifuged or otherwise handled to remove excess bath metal (see 1.2), irregular coatingdistribution is not normally encountered. Drainage problems, which manifest themselves as local excess coating thickness that would interfere withfunction or as edge tears or spikes that prese
34、nt a safety hazard because of their sharpness, are grounds for rejection under the terms of 5.1.A153/A153M 1625.3 Embrittlement is a potential condition of steel that is cold-worked, depending on such factors as the steel type (strengthlevel, aging characteristics), thickness, degree of cold work, a
35、nd galvanizing process. The galvanizer, the designer and thefabricator shall take precautions against embrittlement. The precautions to fabricate properly and prepare the material forgalvanizing to prevent embrittlement are described in Practice A143/A143M.NOTE 4Low service temperatures increase the
36、 risk of brittle failure of all plain carbon steels including those which have been galvanized. Thistemperature embrittling effect varies with type of steel. The expected service temperature should thus be taken into account when selecting steels forgalvanizing.5.4 Malleable castings shall be of suc
37、h composition as will preclude the possibility that they become embrittled by thegalvanizing process, or they shall be either cooled from the anneal, or subsequently heat-treated so as to immunize them againstembrittlement.5.5 The zinc coating shall adhere tenaciously to the surface of the base meta
38、l.5.6 If the galvanized material covered by this specification is bent or otherwise fabricated to the degree that causes the zinccoatings to stretch or compress beyond the limit of elasticity, any cracking or flaking of the coating resulting from the bending orfabricating shall not be cause for reje
39、ction.5.7 High strength bolts, typically over 150,000 lb/in.2 ultimate tensile strength, may be subject to hydrogen embrittlement.Practices to safeguard against hydrogen embrittlement are described in Specification A143/A143M.6. Sampling6.1 Test specimens shall be selected at random from each inspec
40、tion lot.6.2 The method of selection and sample size shall be agreed upon between the galvanizer and the purchaser. Otherwise, thesample size selected from each lot shall be as follows:Number of Pieces in Lot Sample Size3 or less all4 to 500 3501 to 1200 51201 to 3200 83201 to 10 000 1310 001 and ov
41、er 206.3 A specimen that fails to conform to a requirement of this specification shall not be used to determine the conformance toother requirements.TABLE 1 Thickness or Weight Mass of Zinc Coating for Various Classes of MaterialNOTE 1 Length of the piece, stated in Classes B-1, B-2, and B-3, refers
42、 to the finished dimension of the piece after fabrication.Class of MaterialWeight Mass of Zinc Coating,oz/ft 2 g/m2 of Surface, MinimumCoating Thickness, milsmicrons, MinimumAverage ofSpecimensTestedAnyIndividualSpecimenAverage ofSpecimensTestedAnyIndividualSpecimenClass ACastingsMalleable Iron, Ste
43、el 2.00 610 1.80 550 3.4 86 3.1 79Class BRolled, pressed, and forged articles(except those which would be included under Classes C and D):B-158 in. 4.76 mm and over in thicknessand over 15 in. 381 mm in length2.00 610 1.80 550 3.4 86 3.1 79B-158 in. 15.88 mm and over in thicknessand over 15 in. 381
44、mm in length2.00 610 1.80 550 3.4 86 3.1 79B-2under 58 in. 4.76 mm in thickness andover 15 in. 381 mm in length1.50 458 1.25 381 2.6 66 2.1 53B-2under 58 in. 15.88 mm in thickness andover 15 in. 381 mm in length1.50 458 1.25 381 2.6 66 2.1 53B-3any thickness and 15 in. 381 mm and under in length 1.3
45、0 397 1.10 336 2.2 56 1.9 48Class CFasteners over 38 in. 9.52 mm in diameterand similar articles. Washers 316 in. and 14 in. 4.76 and 6.35mm in thickness1.25 381 1.00 305 2.1 53 1.7 43Class CFasteners over 38 in. 9.52 mm in diameterand similar articles. Washers 316 in. and greater 4.76 mm andgreater
46、 in thickness1.25 381 1.00 305 2.1 53 1.7 43Class DFasteners 38 in. 9.52 mm and under in diameter,rivets, nails and similar articles. Washers under 316 in. 4.76mm in thickness1.00 305 0.85 259 1.7 43 1.4 36A153/A153M 1636.4 The method of sampling for fasteners that are required to meet the standards
47、 of the Fastener Quality Act is described inGuide F1470. Sample quantities and definitions of terminology are included in the referenced specification.7. Test Methods7.1 Tests shall be made to ensure that the zinc coating is being furnished in accordance with this specification and as specifiedfor t
48、he following:7.1.1 Minimum coating weight mass or minimum coating thickness in 4.3.7.1.2 Finish and appearance in 5.1 and 5.2.7.1.3 Embrittlement in 5.3 and 5.4.7.1.4 Adherence in 5.5.7.2 Average Weight Mass of Coating : Coating:7.2.1 The average weight mass of the zinc coating shall be determined b
49、y weighing specimens after pickling and drying andagain after galvanizing unless the method described in 7.2.2 is used. The number of specimens that are used to determine theaverage of an inspection lot shall be derived from Section 6.NOTE 5This method does not take into account the weight mass of iron reacted from the article that is incorporated into the coating. It will thusunderestimate coating weight mass
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