ASTMA153∕A153M-05钢铁制金属构件上镀锌层(热浸)标准规范

1、Designation: A 153/A 153M 一 05Amorican Assodatkxi State Highway and Transportation Offtuals Standard AASHTO No. M232Standard Specification forZinc Coating (Hot-Dip) on Iron and Steel HardwareThis spccifkauoa is under the junsdiction of ASTM Committee A05 on Meutlic-C2cva(ed lr<xi and SrecJ Pruduc

2、w and is (he direct responsibility of Subcommittee AO5.I3 on Stnxural Shapes wd Hardware Spccifica(ion$Currcni edition approved April I. 2005. Published May 2005. Originally approved in 1933. last previous edition approved in 2004 as A 153/A I53M 04.This sundard is issued under (he fixed designation

3、 A 15A/A 153M; the number immediaidy following the deignsrion indiem口 the year of xiginal adoption or, in the case of revision, the year of last revision. A number in parcntbcscs indicates che year of iMt reapproval. A superscript epsilon («) indicates an editorial change since the last rcvUion

4、 or rcappcnval.Thu standard has been approved far use byof the Department of Defend.1. Scope拿1.1 This specification covers zinc coatings applied by the hot-dip process on iron and steel hardware. The hot-dip galvanizing process consists of parts being immersed in molten zinc for a sufficient time to

5、 allow a metallurgical reaction between iron from the steel surface and lhe molten zinc, resulting in the fonnation of Zn/Fe alloy layers bonding the coating to the steel surface.1.2 This specification is intended <u be applicable to hardware items that are centrifiiged or otherwise handled to re

6、move excess galvanizing bath metal (free zinc). Coating thickness grade requirements reflect this.13 This specification is applicable to orders in either inch-pound units (as A 】53) or in SI units (as A 153M). Inch-pound units and SI units are not necessarily exact equivalents. Within the text of th

7、is specification and where appropriate, SI units are shown in brackets. Each system shall be used independently of the other without combining values in any way. In the case of orders in SI units, all testing and inspection shall be done using the metric equivalent of the test or inspection method a

8、s appropriate In the case of orders in SI units, 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 concents, if any, associated with its use. It is the responsibility of the uer of this standard to establish appro- priate

9、safety and health practices and determine the applica bilit9 of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards: For referenced ASTM suindarth, visii (he ASTM web&ke. www.asun.orK or condci ASTM Customer Service at sen->ccaj«. For Annual Book of ASTM Su

10、mdarth volume informalion .refer to lhe sundard* Dfxzumcni Summary page oo the ASTM website.A 90/A 90M Test Method for Weight of Coating on Zinc Coated (Galvanized) Iron or Steel ArticlesA 143 Practice for Safeguarding Against Embrittlement of Hot-Dip Galvanized Structural Steel Products and Procs d

11、ure for Detecting RmbrittlementA 780 Practice for Repair of Damaged and Uncoated Areas of Hot-Dip Galvanized CoatingsA 902 Terminology Relating to Metallic Coated Steel ProductsB 6 Specification for Zinc (Slab Zinc)B 487 Test Method for Measurement of Metal and Oxide Coating Thicknesses by Microsc&l

12、t;4)ical Examination of a Cross SectionE 376 Practice for Measuring Coating Thickness by Magnetic-Field or Eddy-Current (Electromagnetic) Test MethodsF 1470 Guide for Fastener Sampling for Specified Mechanical Properties and Performance InspectionF 1789 Terminology for F16 Mechanical Fasteners3. Ter

13、minology3.1 Definitions:3The following terms and definitions are specific to this specification. Terminology A 902 contains other lerms and definitions relating to metallic-coated steel products. Terminol ogy F 1789 contains other terms and definitions relating to mechanical fasteners3.2 Definitions

14、 cf Terms Specific to This Standard:3.2average coating thickness, nthe average of the specimen coaUng thiclmess values for 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 coating3.23 dross inclusions, nthe iron/zinc i

15、ntcrmetallics present in a galvanized coating in a form other than the layer growth of the coating.individual measurement, nthe reading from a magnetic thickness gauge of a single coating spot thickness, or the microscopic reading of a coating thickness as seen in an optical microscope a( one spot.A

16、 Summarv of Changes section appears at the end of this standard.Copyright C ASTM International. 100 8arr Hartwr Dnve. PO Bax C700. WMt Constiobocken. PA 19423-2959. UntM SlatMA153/A153M-054#3.2.4 inspection lot, nhe quantity of identical parts cleaned, fluxed and galvanized together at one time in a

17、n appropriate container that is being submitted for acceptance as a group3.2.5 malleable casting, na steel article that has been subjected to a prolonged anneal to decarburize or graphitize the part to remove as much of the carbon as possible or to convert the carbon to giaphiie. which permits plast

18、ic deformation in compression without rupture.3.2.6 sample, na collection of individual units of product from a single inspection lot selected in accordance with Section 6 and intended to represent that inspection lot for acceptance3.2.7 specimen, nan individual test article upon which thickness mea

19、surements or weight detenninadons are performed.3.2.8 specimen coating thickness, n_ e average thickness from no less than five test measurements on a specimen, when each measurement location is selected to provide the widest dispersion (in al) applicable directions) of locations within the specimen

20、 volume3.2.9 threaded areas n_ e sections of a steel part that have threads formed before hot-dip galvanizing.4. Materials and Manufacture4J 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 coaling shall

21、 conform to Specification B6 and shall be at least equal to the grade designated as ''Prime Western.04.2.1 If a zinc alloy is used as the primary feed for the galvanizing bath, then the base material used to make that alloy shall conform to Specification B The molten metal in the wor

22、king volume of the galvanizing bath shall contain no< less than an average value of 98.0 % zinc by weight mass.Nui b 1Tlic galvoiiici may gIjuum; lu add Uacc aii>uuuu of cdtain elements (for example, aluminum. nickd9 bismuth9 or tin) to the zinc bath to help in the prozessing of certain reacti

23、ve steels or to enhance the cosmetic appearance of (he finished product. The elements can be added to the galvanising bath as a master feed alloy, or they can be added to the bath by the galvanizcr as individual feeds4.3 Minimum Coating Weight Mass or Minimum Coating ThicknessThe minimum coating wei

24、ght mass or the mini mum coating thickness shall conform to the requirements prescribed in Table 1 for the material category and thickness of material in which the article belongs4.4 Threaded Articles_The zinc coating on threads shall not be subjected to a cutting, rolling, or finishing-tool opera-

25、lion, unless specifically authorized by the purchaser. In order to meet overtapping allowances, tapping the threads of nuts or tapped holes after galvanizing is not prohibited4.5 Touch-up and RepairBare spots that are found on parts after galvanizing shall be renovated by use of the methods found in

26、 Practice A 780 if the following criteria are me(. The bare spots shall have an area totalling not more than 1 % of the surface area to be coated excluding threaded areas of the piece and the bare spots shall not include any threaded areas of the piece. The thickness of the repair shall be equal to

27、the sunounding galvanized coating except for repairs made by paints containing zinc dust in which case the thickness of the repair shall be 50 % greater than the thickness of the galvanized coating required for the class of material, but shall no< be greater than 4.0 mils 100 pn. Repair thickness

28、 measurements shall be made in accordance with Practice A 780. The galva- nizer shall make repairs unless directed by the purchaser to deliver items unrepaired for subsequent renovation by the purchaser.5. Workmanship Finish, and Appearance5.1 The zinc-coated articles shall be free from uncoated are

29、as, blisters, flux deposits, dross inclusions, and ocher types of projections 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 smooth and reasonably uniform in thickness.Norc 2Sn»o(hness of s

30、urface is a relative (erm Minor roughness that does noc interfere with the intended use of the part, or roughness(ha<#TABLE 1 Thldcne88 or Weight Mass of Zinc Coating for Various Classes of MaterialNote l Length of the piece, stated in Classes B-l. B2. and B-3, refere to the finished dimension of

31、 the piece after fabrication.Class of MaterialWeight MassJ & Zinc Coating, oz/h2! o< Surface. MinimumCoating Th»ckness. mte microns. MinimumAverage of Speamens TestedAny Individual SpecimenAverage of Specimens TestedAny rndivkJual SpecimenClass ACastngMalleable Iron. SteelClass 8Rolled,

32、pressed, and forged articles (excepi those which woukJ be included under Classes C and D):2.00(6101.80 (55013.4 863.1 79B-1-in. 4.76 rrm) and over In thickness and over 15 in. 381 mm) in length2.00 01.8015503.4 (86)3.1 (79)B-2under Vie in. (4.76 mm in thickness and ovQr 15 in. 381 rmr j in length1.5

33、0 (45825 3812.6 (66)2.1 53JB-3 y thickness and IS in. 381 mmj and under in length1.30 (3971.10(336)2.2 (561.9 (4B)Class CFasteners over % in. (9.52 mm) In diameter and similar articles. Washersin. and % in. 4.76 and 6.35mmj in thickness1.2S 3811.00 3052.1 5317 (<3jClass £>Fasteners H in.

34、(9.52 mmj and under in diameter, rivets, nais and sfcritar anides Washers under 兔 in. 4.76 mm in ttiickness1.00 3050.85 (2591.7 4314 136)#A153/A153M-05is related (o the as-received (ungalvanized) surface condition of the part, shall not be grounds for rejection.Note 3Since this specification is appl

35、icable (o items that arc ccntri fuged or otherwise handled to remove excess bath metal (sec L2), irregular coating distribution is not normally encountcred Drainage problems, which rranifest themselves as local excess coating thickness chat would interfere with function or as edge tears or spikes th

36、at present a safety hazard because of their sharpness, arc grounds for rejection under the terms of 5.5.3 Embritdenient is a potential condition of steel that is cold-workcd, depending on such factors as the steel type (strength level, aging characteristics), thickness, degree of cold work, and galv

37、anizing process The galvanizer, the designer and the fabricator shall take precautions against embrittlement. The precautions to fabricate properly and prepare the material for galvanizing to prevent cmbriitlcment are described in Practice A 143.Note 4Low service temperatures increase the risk of br

38、ittle failure of all plain carbon steals including those which have been galvanized. This temperature embrittling effect varies with type of steel. The expected service lemperaiure should thus be taken into account when selecting sleek for galvanizin&5.4 Malleable castings shall be of such compo

39、sition as will preclude the possibility that they become embrittled by the galvanizing process, or they shall be either cooled from the anneal, or subsequently heat-treated so as to immunize them against embrittlement.5.5 The zinc coating shall adhere tenaciously to the surface of the base metal.5.6

40、 If the galvanized material covered by this specification is bent or otherwise fabricated to the degree that causes the zinc coatings to stretch or compress beyond the limit of elasticity* any cracking or flaking of the coating resulting from the bending or fabricaung shall not be cause for rejectio

41、n.6. Sampling6.1 Test specimens shall be selected at random from each inspection lot.6.2 The method of selection and sample size shall be agreed upon between the galvanizer and the purchaser. Otherwise, the sample size selected from each lot shall be as follows:Number of Pieces in LotSampleSize3 “ t

42、ossall4t>5003S01 to 120051201 to 320083201 to 10 0001310 001 and over206.3 A specimen that fails to conform to a requirement of this specification shall not be used to determine lhe conformance to other requirements6.4 The method of sampling for fasteners that arc required to meet the standards o

43、f the Fastener Quality Act is described in Guide F 1470. Sample quantities and definitions of terminology are included in the referenced specification7. Test Methods7.1 Tests shall be made to ensure that the zinc coating is being furnished in accordance with this specification and as specified for l

44、he following:7Minimum coating weight mass or minimum coating thickness in 437.1.2 Finish and appearance in 5.1 and .3 Embrittlement in 5.3 and .4 Adherence in Average Weight Mass of Coating:7.2.1 The average weight mass of (he zinc coating shall be determined by weighing specim

45、ens after pickling and drying and again after galvanizing unless the method described in7.2.2 is used. The number of specimens that are used to determine the average of an inspection lot shall be derived firom Section 6Note 5This method does not take into account che weighc (mass) of iron reacted fi

46、rm (be article that is incorporated into the coating. It will thus underestimate coating weight |mass by up to approxima(cly 10% Base metal reactivity will affect the extent of underestimation.7.2.2 In the case of materials inspected after galvanizing, the average weight mass of coating shall be det

47、ermined by stripping the number of specimens derived in Section 6 in accordance with Test Method A 90/A 90M, and averaging the results of the individual specimens, unless the method described in 721 is used.7.3 Average Thickness of Coating:7.3.1 In the case of fasteners such as bolts, nuts, and scre

48、ws, the determination of the thickness of coating shall be made on a portion of the article that does not include any threads.7.3.2 The average thickness of coating shall be determined by magnetic thickness gage in accordance with Practice E 376 unless the method described in 7.3.3 is used. The thic

49、kness shall be measured on at least five widely separated spots on a specimen. No individual spot measurement shall be cause for rejection If an individual spot does not provide a coating thickness reading, this spot must be repaired in accordance with 4.5. The five or more individual coating thickn

50、ess measurements on a specimen must be averaged to determine the specimen average coating thickness. The average coating thickness for the inspection lot is determined by averaging the specimen average coating thickness values for the number of specimens derived from Section 6.733 The thickness of c

51、oating shall be determined by cross section and optical measurement in accordance with Test Method B 487, unless the method described in 7.3.2 is used. The (hickness thus determined is a point value No less than five such measurements shall be made at locations on the specimen, which are as widely d

52、ispersed as practical, so as (o be representative of the whole surface of the specimen The average of no less than five such measurements is the specimen average coating thickness The average coating thickness for the inspection lot is determined by averaging the specimen average coating thickness v

53、alues for the number of specimens derived from Section 6.7.4 Finish and AppearanceThe test for finish and appearance shall be conducted through visual inspection without additional magnification.EmhriulementHardware (hat is susceptible to em brittlement shall be tested in accordance with Practice A

54、143. The tests shall be performed through agreement between the galvanizer and the purchaser.54SJ|F A153/A153M-056#7.5 AdherenceDetermine adherence of the zinc coating to the surface of the base meta by cutting or prying with the point of a stout knife, applied with considerable pressure in a manner

55、 tending to remove a portion of the coating The adherence shall be considered inadequate if the coating delaminates in the form of a layer of skin so as to expose the base metal in advance of the knife point. Do no( use testing carried out at edges or comers (points of lowest coating adherence) to d

56、etermine adherence of coating Likewise, do not use removal of small particles of the coating by paring or whittling to determine failure.8. Inspection8.1 The inspector representing the purchaser shall have access at all times while work on lhe contract of the purchaser is being performed, to those a

57、reas of the manufacturer's work which concern the application of the zinc coating to the material ordered. The manufacturer shall afford the inspector all reasonable facilities to satisfy him that the zinc coating is being furnished in accordance with this specification All inspection and tests

58、shall be made at the place of manufacture prior to shipments, unless otherwise specified, and shall be so conducted as ncx co interfere unnecessarily with the operation of the works9. Rejection and Retest9.1 For all galvanized articles except those fasteners that must meet the requirements of the Fastener Quality Act, lhe following sections are used to determine rejection and retesting.9.2 When partial inspection of materials to determine conformity with visual requirement