1、Designation: A123/A123M 17Standard Specification forZinc (Hot-Dip Galvanized) Coatings on Iron and SteelProducts1This standard is issued under the fixed designation A123/A123M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the ye
2、ar 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 use by agencies of the U.S. Department of Defense.1. Scope*1.1 This specification covers
3、 the requirements for zinccoating (galvanizing) by the hot-dip process on iron and steelproducts made from rolled pressed and forged shapes, castings,plates, bars, and strips.1.2 This specification covers both unfabricated products andfabricated products, for example, assembled steel products,struct
4、ural steel fabrications, large tubes already bent or weldedbefore galvanizing, and wire work fabricated from uncoatedsteel wire. This specification also covers steel forgings and ironcastings incorporated into pieces fabricated before galvanizingor which are too large to be centrifuged (or otherwise
5、 handledto remove excess galvanizing bath metal).NOTE 1This specification covers those products previously addressedin Specifications A123-78 and A386-78.1.3 This specification does not apply to wire, pipe, tube, orsteel sheet which is galvanized on specialized or continuouslines, or to steel less t
6、han 22 gage (0.0299 in.) 0.76 mm thick.1.4 The galvanizing of hardware items that are to becentrifuged or otherwise handled to remove excess zinc (suchas bolts and similar threaded fasteners, castings and rolled,pressed and forged items) shall be in accordance with Speci-fication A153/A153M.1.5 Fabr
7、icated reinforcing steel bar assemblies are coveredby the present specification. The batch galvanizing of separatereinforcing steel bars shall be in accordance with SpecificationA767/A767M and the continuous galvanizing of reinforcingbars shall be in accordance with Specification A1094/A1094M.1.6 Th
8、is specification is applicable to orders in eitherinch-pound units (as A123) or SI units (as A123M). Inch-pound units and SI units are not necessarily exact equivalents.Within the text of this specification and where appropriate, SIunits are shown in parentheses. Each system shall be usedindependent
9、ly of the other without combining values in anyway. In the case of orders in SI units, all testing and inspectionshall be done using the metric equivalent of the test orinspection method as appropriate. In the case of orders in SIunits, such shall be stated to the galvanizer when the order isplaced.
10、1.7 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to
11、 Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2A47/A47M Specification for Ferritic Malleable Iron Cast-ingsA90/A90M Test Method for Weight Mass of Coating onIron and Steel Articles with Zinc or Zinc-Alloy CoatingsA143/A143M Practice for Safeguarding Against Embrittle-ment of Hot-D
12、ip Galvanized Structural Steel Products andProcedure for Detecting EmbrittlementA1094/A1094M Specification for Continuous Hot-Dip Gal-vanized Steel Bars for Concrete ReinforcementA153/A153M Specification for Zinc Coating (Hot-Dip) onIron and Steel HardwareA384/A384M Practice for Safeguarding Against
13、 Warpageand Distortion During Hot-Dip Galvanizing of SteelAssembliesA385 Practice for Providing High-Quality Zinc Coatings(Hot-Dip)A767/A767M Specification for Zinc-Coated (Galvanized)Steel Bars for Concrete ReinforcementA780 Practice for Repair of Damaged and Uncoated Areasof Hot-Dip Galvanized Coa
14、tingsA902 Terminology Relating to Metallic Coated Steel Prod-ucts1This specification is under the jurisdiction of ASTM Committee A05 onMetallic-Coated Iron and Steel Products and is the direct responsibility ofSubcommittee A05.13 on Structural Shapes and Hardware Specifications.Current edition appro
15、ved Sept. 1, 2017. Published September 2017. Originallyapproved in 1928. Last previous edition approved in 2015 as A123/A123M - 15.DOI: 10.1520/A0123_A0123M-17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of
16、 ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.*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 StatesThis international stan
17、dard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1B6 Sp
18、ecification for ZincB487 Test Method for Measurement of Metal and OxideCoating Thickness by Microscopical Examination ofCross SectionB602 Test Method for Attribute Sampling of Metallic andInorganic CoatingsB960 Specification for Prime Western Grade-Recycled(PWG-R) ZincD6386 Practice for Preparation
19、of Zinc (Hot-Dip Galva-nized) Coated Iron and Steel Product and HardwareSurfaces for PaintingD7803 Practice for Preparation of Zinc (Hot-Dip Galva-nized) Coated Iron and Steel Product and HardwareSurfaces for Powder CoatingE376 Practice for Measuring Coating Thickness byMagnetic-Field or Eddy-Curren
20、t (Electromagnetic) Test-ing Methods3. Terminology (See Fig. 1)3.1 Definitions:3.1.1 The following terms and definitions are specific to thisspecification. Terminology A902 contains other terms anddefinitions relating to metallic-coated steel products.3.2 Definitions of Terms Specific to This Standa
21、rd:3.2.1 average coating thickness, nthe average of threespecimen coating thicknesses.3.2.2 black, adjdenotes the condition of not galvanized orotherwise coated. For purposes of this specification the word“black” does not refer to the color or condition of surface, or toa surface deposit or contamin
22、ation.3.2.3 coating thickness grade, nthe numerical value fromTable 1 at the intersection of a material category and athickness range.3.2.4 gross dross inclusions, nthe iron/zinc intermetallicspresent in a galvanized coating in a form other than finelydispersed pimples.3.2.4.1 DiscussionThese inclus
23、ions would create an ex-posed steel spot if they were removed from the coating. Theseinclusions are raised surfaces and are easily knocked offthrough contact with lifting straps or chains, tools, fixtures, orother galvanized parts.3.2.5 material category, nthe general class or type ofmaterial or pro
24、cess of manufacture, or both, that nominallydescribes a unit of product, or from which a unit of product ismade. For example, bar grating belongs to the category “strip,”handrail belongs to the category “pipe,” etc.3.2.6 multi-specimen article, na unit of product whosesurface area is greater than 16
25、0 in.2100 000 mm2. Forthickness testing purposes, articles whose surface area isgreater than 160 in.2are subdivided into three continuous localsections, nominally equal in surface area, each of whichconstitutes a specimen. In the case of any such local sectioncontaining more than one material catego
26、ry or steel thicknessrange as delineated in Table 1, that section will contain morethan one specimen (see Fig. 1).3.2.7 sample, na collection of individual units of productfrom a single lot selected in accordance with Section 7, andintended to represent that lot for acceptance. If a sample istaken a
27、s representing the lot for acceptance, the sample shall betaken at random from the lot without regard to the perceivedquality or appearance of any individual unit in the lot beingsampled. The sample consists of one or more test articles.3.2.8 single-specimen article, na unit of product whosesurface
28、area is equal to or less than 160 in.2100 000 mm2orthat is centrifuged or otherwise similarly handled in thegalvanizing process to remove excess galvanizing bath metal(free zinc). For thickness testing purposes, the entire surfacearea of each unit of product constitutes a specimen. In the caseof any
29、 such article containing more than one material categoryor steel thickness range as delineated in Table 1, that articlewill contain more than one specimen (see Fig. 1).3.2.9 specimen, nthe surface of an individual test articleor a portion of a test article, upon which thickness measure-ments are to
30、be performed, which is a member of a lot, or amember of a sample representing that lot. For magneticthickness measurements, specimen excludes any area of thesurface which is subject to processes (such as flame cutting,machining, threading, etc.) that can be expected to result insurface conditions no
31、t representative of the general surfacecondition of the test article, or is disqualified by the measure-ment method. The minimum average coating thickness gradefor any specimen shall be one coating grade below thatrequired for the appropriate material category and thickness inTable 1. For a unit of
32、product whose surface area is equal to orless than 160 in.2100 000 mm2, the entire surface area ofeach test article constitutes a specimen. In the case of an articlecontaining more than one material category or steel thicknessrange as delineated in Table 1, that article will contain morethan one spe
33、cimen, as appropriate (see Fig. 1).3.2.10 specimen coating thickness, nthe average thicknessfrom no less than five test measurements on a specimen, wheneach measurement location is selected to provide the widestTABLE 1 Minimum Average Coating Thickness Grade by Material CategoryMaterial CategoryAll
34、Specimens TestedSteel Thickness Range (Measured), in. mm1161.6$116 to 18$1.6 to 3.2$18 to 316$3.2to4.8$316 to 14$4.8 to 6.4$14 to 58$6.4 to 16.0$58$16.0Structural Shapes 45 65 75 75 100 100Strip and Bar 45 65 75 75 75 100Plate 45 65 75 75 75 100Pipe and Tubing 45 45 75 75 75 75Wire 35 50 60 65 80 80
35、Reinforcing Bar . . . . 100 100A123/A123M 172dispersion (in all applicable directions) of locations for thesteel category of the test article within the confines of thespecimen volume.3.2.11 test article, nan individual unit of product that is amember of the sample and that is examined for conforman
36、ce toa part of this specification.4. Ordering Information4.1 Orders for coatings provided under this specificationshall include the following:4.1.1 Quantity (number of pieces to be galvanized) and totalweight.4.1.2 Description (type and size of products) and weight.4.1.3 ASTM specification designati
37、on and year of issue.4.1.4 Material identification (see 5.1) and surface conditionor contamination.4.1.5 Sampling plan, if different from 7.3.4.1.6 Special test requirements (see 8.1).4.1.7 Special requirements (special stacking, heavier coat-ing weight, etc.).FIG. 1 Single- and Multi-Specimen Artic
38、lesA123/A123M 1734.1.8 Tagging or piece identification method.5. Materials and Manufacture5.1 Steel or IronThe specification, grade, or designationand type and degree of surface contamination of the iron orsteel in articles to be galvanized shall be supplied by thepurchaser to the hot-dip galvanizer
39、 prior to galvanizing.NOTE 2The presence in steels and weld metal, in certain percentages,of some elements such as silicon, carbon, and phosphorus tends toaccelerate the growth of the zinc-iron alloy layer so that the coating mayhave a matte finish with little or no outer zinc layer. The galvanizer
40、hasonly limited control over this condition. The mass, shape, and amount ofcold working of the product being galvanized may also affect thiscondition. Practice A385 provides guidance on steel selection anddiscusses the effects of various elements in steel compositions (forexample, silicon), that inf
41、luence coating weight and appearance.5.2 FabricationThe design and fabrication of the productto be galvanized are the responsibilities of the designer and thefabricator. Practices A143/A143M, A384/A384M, and A385provide guidance for steel fabrication for optimum hot dipgalvanizing and shall be compl
42、ied with in both design andfabrication. Consultation between the designer, fabricator, andgalvanizer at appropriate stages in the design and fabricationprocess will reduce future problems.5.3 CastingsThe composition and heat treatment of ironand steel castings shall conform to specifications designa
43、ted bythe purchaser. Some types of castings have been known toshow potential problems with predisposition to being em-brittled during the normal thermal cycle of hot-dip galvanizing.It is the responsibility of the purchaser to heat treat orotherwise allow for the possibility of such embrittling phen
44、om-ena. The requirements for malleable iron castings to begalvanized shall be as stated in Specification A47/A47M.5.4 ZincThe zinc used in the galvanizing bath shallconform to Specification B6, or Specification B960, or both. Ifa zinc alloy is used as the primary feed to the galvanizing bath,then th
45、e base material used to make that alloy shall conform toSpecification B6, or Specification B960, or both.5.5 Bath CompositionThe molten metal in the workingvolume of the galvanizing bath shall contain not less than anaverage value of 98.0 % zinc by weight.NOTE 3The galvanizer may choose to add trace
46、 amounts of certainelements (for example, aluminum, nickel, and tin) to the zinc bath to helpin the processing of certain reactive steels or to enhance the cosmeticappearance of the finished product. The use of these trace elements ispermitted provided that the bulk chemistry of the galvanizing bath
47、 is atleast 98.0 % zinc by weight. The elements can be added to the galvanizingbath as part of a pre-alloyed zinc feed, or they can be added to the bath bythe galvanizer using a master feed alloy.6. Coating Properties6.1 Coating ThicknessThe average thickness of coatingfor all specimens tested shall
48、 conform to the requirements ofTable 1 for the categories and thicknesses of the material beinggalvanized. Minimum average thickness of coating for anyindividual specimen is one coating grade less than that requiredin Table 1. Where products consisting of various materialthicknesses or categories ar
49、e galvanized, the coating thicknessgrades for each thickness range and material category ofmaterial shall be as shown in Table 1. In the case of orders inSI units, the values in Table 1, shall be applicable as metricunits in micrometres. In the case of orders in inch-pound units,the measured value shall be converted to coating grade units bythe use of Table 2. The specification of coating thicknessesheavier than those required by Table 1 shall be subject tomutual agreement between the galvanizer and the purchaser.(Fig. 2 is a gr
