1、Designation: A123/A123M 12A123/A123M 13Standard 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 rev
2、ision, 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 use by agencies of the Department of Defense.1. Scope*1.1 This specificatio
3、n covers the requirements for zinc coating (galvanizing) by the hot-dip process on iron and steel productsmade from rolled pressed and forged shapes, castings, plates, bars, and strips.1.2 This specification covers both unfabricated products and fabricated products, for example, assembled steel prod
4、ucts,structural steel fabrications, large tubes already bent or welded before galvanizing, and wire work fabricated from uncoated steelwire. This specification also covers steel forgings and iron castings incorporated into pieces fabricated before galvanizing or whichare too large to be centrifuged
5、(or otherwise handled to remove excess galvanizing bath metal).NOTE 1This specification covers those products previously addressed in Specifications A123-78 and A386-78.1.3 This specification does not apply to wire, pipe, tube, or steel sheet which is galvanized on specialized or continuous lines,or
6、 to steel less than 22 gage (0.0299 in.) 0.76 mm thick.1.4 The galvanizing of hardware items that are to be centrifuged or otherwise handled to remove excess zinc (such as bolts andsimilar threaded fasteners, castings and rolled, pressed and forged items) shall be in accordance with Specification A1
7、53/A153M.1.5 Fabricated reinforcing steel bar assemblies are covered by the present specification. The galvanizing of separate reinforcingsteel bars shall be in accordance with Specification A767/A767M.1.6 This specification is applicable to orders in either inch-pound units (as A123) or SI units (a
8、s A123M). Inch-pound units andSI units are not necessarily exact equivalents. Within the text of this specification and where appropriate, SI units are shown inparentheses. Each system shall be used independently of the other without combining values in any way. In the case of orders inSI units, all
9、 testing and inspection shall be done using the metric equivalent of the test or inspection method as appropriate. In thecase of orders in SI units, such shall be stated to the galvanizer when the order is placed.2. Referenced Documents2.1 ASTM Standards:2A47/A47M Specification for Ferritic Malleabl
10、e Iron CastingsA90/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 Products and Procedurefor Detecting EmbrittlementA153/A153M Specification for Zi
11、nc Coating (Hot-Dip) on Iron and Steel HardwareA384/A384M Practice for Safeguarding Against Warpage and Distortion During Hot-Dip Galvanizing of Steel AssembliesA385 Practice for Providing High-Quality Zinc Coatings (Hot-Dip)A767/A767M Specification for Zinc-Coated (Galvanized) Steel Bars for Concre
12、te ReinforcementA780 Practice for Repair of Damaged and Uncoated Areas of Hot-Dip Galvanized CoatingsA902 Terminology Relating to Metallic Coated Steel ProductsB6 Specification for Zinc1 This specification is under the jurisdiction ofASTM Committee A05 on Metallic-Coated Iron and Steel Productsand i
13、s the direct responsibility of Subcommittee A05.13on Structural Shapes and Hardware Specifications.Current edition approved May 1, 2012Nov. 1, 2013. Published July 2012November 2013. Originally approved in 1928. Last previous edition approved in 20092012 asA123/A123M - 09.- 12. DOI: 10.1520/A0123_A0
14、123M-12.10.1520/A0123_A0123M-13.2 For referencedASTM standards, visit theASTM 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
15、standard and is intended only to provide the user of an ASTM standard an indication 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
16、cases only the current versionof the standard as published by ASTM is to be 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 States1B487 Test Me
17、thod for Measurement of Metal and Oxide Coating Thickness by Microscopical Examination of Cross SectionB602 Test Method for Attribute Sampling of Metallic and Inorganic CoatingsB960 Specification for Prime Western Grade-Recycled (PWG-R) ZincE376 Practice for Measuring Coating Thickness by Magnetic-F
18、ield or Eddy-Current (Electromagnetic) Testing Methods3. Terminology (See Fig. 1)3.1 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.3.2 Definitions of Terms Spec
19、ific to This Standard:3.2.1 average coating thickness, nthe average of three specimen coating thicknesses.FIG. 1 Single- and Multi-Specimen ArticlesA123/A123M 1323.2.2 black, adjdenotes the condition of not galvanized or otherwise coated. For purposes of this specification the word“black” does not r
20、efer to the color or condition of surface, or to a surface deposit or contamination.3.2.3 coating thickness grade, nthe numerical value from Table 1 at the intersection of a material category and a thicknessrange.3.2.4 gross dross inclusions, nthe iron/zinc intermetallics present in a galvanized coa
21、ting in a form other than finely dispersedpimples.3.2.4.1 DiscussionThese inclusions would create an exposed steel spot if they were removed from the coating. These inclusions are raised surfacesand are easily knocked off through contact with lifting straps or chains, tools, fixtures, or other galva
22、nized parts.3.2.5 material category, nthe general class or type of material or process of manufacture, or both, that nominally describesa unit of product, or from which a unit of product is made. For example, bar grating belongs to the category “strip,” handrailbelongs to the category “pipe,” etc.3.
23、2.6 multi-specimen article, na unit of product whose surface area is greater than 160 in.2 100 000 mm2. For thicknesstesting purposes, articles whose surface area is greater than 160 in.2 are subdivided into three continuous local sections, nominallyequal in surface area, each of which constitutes a
24、 specimen. In the case of any such local section containing more than one materialcategory or steel thickness range as delineated in Table 1, that section will contain more than one specimen (see Fig. 1).3.2.7 sample, na collection of individual units of product from a single lot selected in accorda
25、nce with Section 7, and intendedto represent that lot for acceptance. If a sample is taken as representing the lot for acceptance, the sample shall be taken at randomfrom the lot without regard to the perceived quality or appearance of any individual unit in the lot being sampled. The sampleconsists
26、 of one or more test articles.3.2.8 single-specimen article, na unit of product whose surface area is equal to or less than 160 in.2 100 000 mm2 or thatis centrifuged or otherwise similarly handled in the galvanizing process to remove excess galvanizing bath metal (free zinc). Forthickness testing p
27、urposes, the entire surface area of each unit of product constitutes a specimen. In the case of any such articlecontaining more than one material category or steel thickness range as delineated in Table 1, that article will contain more thanone specimen (see Fig. 1).3.2.9 specimen, nthe surface of a
28、n individual test article or a portion of a test article, upon which thickness measurements areto be performed, which is a member of a lot, or a member of a sample representing that lot. For magnetic thickness measurements,specimen excludes any area of the surface which is subject to processes (such
29、 as flame cutting, machining, threading, etc.) that canbe expected to result in surface conditions not representative of the general surface condition of the test article, or is disqualifiedby the measurement method. The minimum average coating thickness grade for any specimen shall be one coating g
30、rade belowthat required for the appropriate material category and thickness in Table 1. For a unit of product whose surface area is equal toTABLE 1 Minimum Average Coating Thickness Grade by Material CategoryMaterial CategoryAll Specimens TestedSteel Thickness Range (Measured), in. (mm)316 to 4.8 to
31、 316 to 4.8 to 5816.0Structural 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 80Reinforcing Bar . . . . 100 100A123/A123M 133or less than 160 in.2 100 000 mm2, the entire surface area of each test article consti
32、tutes a specimen. In the case of an articlecontaining more than one material category or steel thickness range as delineated in Table 1, that article will contain more thanone specimen, as appropriate (see Fig. 1).3.2.10 specimen coating thickness, nthe average thickness from no less than five test
33、measurements on a specimen, when eachmeasurement location is selected to provide the widest dispersion (in all applicable directions) of locations for the steel categoryof the test article within the confines of the specimen volume.3.2.11 test article, nan individual unit of product that is a member
34、 of the sample and that is examined for conformance toa part of this specification.4. Ordering Information4.1 Orders for coatings provided under this specification shall include the following:4.1.1 Quantity (number of pieces to be galvanized) and total weight.4.1.2 Description (type and size of prod
35、ucts) and weight.4.1.3 ASTM specification designation and year of issue.4.1.4 Material identification (see 5.1) and surface condition or 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 coating we
36、ight, etc.).4.1.8 Tagging or piece identification method.5. Materials and Manufacture5.1 Steel or IronThe specification, grade, or designation and type and degree of surface contamination of the iron or steel inarticles to be galvanized shall be supplied by the purchaser to the hot-dip galvanizer pr
37、ior to galvanizing.NOTE 2The presence in steels and weld metal, in certain percentages, of some elements such as silicon, carbon, and phosphorus tends to acceleratethe growth of the zinc-iron alloy layer so that the coating may have a matte finish with little or no outer zinc layer. The galvanizer h
38、as only limited controlover this condition. The mass, shape, and amount of cold working of the product being galvanized may also affect this condition. Practice A385 providesguidance on steel selection and discusses the effects of various elements in steel compositions (for example, silicon), that i
39、nfluence coating weight andappearance.5.2 FabricationThe design and fabrication of the product to be galvanized are the responsibilities of the designer and thefabricator. Practices A143/A143M, A384/A384M, and A385 provide guidance for steel fabrication for optimum hot dipgalvanizing and shall be co
40、mplied with in both design and fabrication. Consultation between the designer, fabricator, andgalvanizer at appropriate stages in the design and fabrication process will reduce future problems.5.3 CastingsThe composition and heat treatment of iron and steel castings shall conform to specifications d
41、esignated by thepurchaser. Some types of castings have been known to show potential problems with predisposition to being embrittled during thenormal thermal cycle of hot-dip galvanizing. It is the responsibility of the purchaser to heat treat or otherwise allow for thepossibility of such embrittlin
42、g phenomena. The requirements for malleable iron castings to be galvanized shall be as stated inSpecification A47/A47M.5.4 ZincThe zinc used in the galvanizing bath shall conform to Specification B6, or Specification B960, or both. If a zinc alloyis used as the primary feed to the galvanizing bath,
43、then the base material used to make that alloy shall conform to SpecificationB6, or Specification B960, or both.5.5 Bath CompositionThe molten metal in the working volume of the galvanizing bath shall contain not less than an averagevalue of 98.0 % zinc by weight.NOTE 3The galvanizer may choose to a
44、dd trace amounts of certain elements (for example, aluminum, nickel, and tin) to the zinc bath to help in theprocessing of certain reactive steels or to enhance the cosmetic appearance of the finished product. The use of these trace elements is permitted providedthat the bulk chemistry of the galvan
45、izing bath is at least 98.0 % zinc by weight. The elements can be added to the galvanizing bath as part of a pre-alloyedzinc feed, or they can be added to the bath by the galvanizer using a master feed alloy.6. Coating Properties6.1 Coating ThicknessThe average thickness of coating for all specimens
46、 tested shall conform to the requirements of Table1 for the categories and thicknesses of the material being galvanized. Minimum average thickness of coating for any individualspecimen is one coating grade less than that required in Table 1. Where products consisting of various material thicknesses
47、orcategories are galvanized, the coating thickness grades for each thickness range and material category of material shall be as shownin Table 1. In the case of orders in SI units, the values in Table 1, shall be applicable as metric units in micrometres. In the caseof orders in inch-pound units, th
48、e measured value shall be converted to coating grade units by the use of Table 2. The specificationof coating thicknesses heavier than those required by Table 1 shall be subject to mutual agreement between the galvanizer and thepurchaser. (Fig. 2 is a graphic representation of the sampling and speci
49、men delineation steps, and Fig. 3 is a graphic representationof the coating thickness inspection steps.)A123/A123M 1346.1.1 For articles whose surface area is greater than 160 in.2 100 000 mm2 (multi-specimen articles), each test article in thesample must meet the appropriate minimum average coating thickness grade requirements of Table 1, and each specimen coatingthickness grade comprising that overall average for each test article shall average not less than one coating grade below thatrequired in Table 1.6.1.2 For articles whose surface a
