Designation:A123/A123M–02
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Standard Specification for
Zinc(Hot-Dip Galvanized)Coatings on Iron and Steel Products1
This standard is issued under thefixed designation A123/A123M;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(e)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 specification covers the requirements for zinc coating(galvanizing)by the hot-dip process on iron and steel products made from rolled presd and forged shapes,castings, plates,bars,and strips.
1.2This specification covers both unfabricated products and fabricated products,for example,asmbled steel products, structural steel fabrications,large tubes already bent or welded before galvanizing,and wire work fabricated from uncoated steel wire.This specification also covers steel forgings and iron castings incorporated into pieces fabricated before galvanizing or which are too large to be centrifuged(or otherwi handled to remove excess galvanizing bath metal).
N OTE1—This specification covers tho products previously addresd in Specifications A123-78and A386-78.
1.3This specification does not apply to wire,pipe,tube,or steel sheet which is galvanized on specialized or continuous lines,or to steel less than22gage(0.0299in.)[0.76mm]thick.
1.4The galvanizing of hardware items that are to be centrifuged or otherwi handled to remove exc
ess zinc(such as bolts and similar threaded fasteners,castings and rolled, presd and forged items)shall be in accordance with Speci-fication A153/A153M.
1.5Fabricated reinforcing steel bar asmblies are covered by the prent specification.The galvanizing of parate reinforcing steel bars shall be in accordance with Specification A767/A767M.
笔记本怎么插网线1.6This specification is applicable to orders in either inch-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,SI units are shown in parenthes.Each system shall be ud independently of the other without combining values in any way.In the ca of orders in SI units,all testing and inspection shall be done using the metric equivalent of the test or inspection method as appropriate.In the ca of orders in SI units,such shall be stated to the galvanizer when the order is placed.
2.Referenced Documents
2.1ASTM Standards:
A47/A47M Specification for Ferritic Malleable Iron Cast-ings2
A90/A90M Test Method for Weight[Mass]of Coating on Iron and Steel Articles with Zinc or Zinc-Alloy Coatings3 A143Practice for Safeguarding Against Embrittlement of Hot-Dip Galvanized Structural Steel Products and Proce-dure for Detecting Embrittlement3
A153/A153M Specification for Zinc Coating(Hot-Dip)on Iron and Steel Hardware3
A384/A384M Practice for Safeguarding Against Warpage and Distortion During Hot-Dip Galvanizing of Steel As-mblies3
A385Practice for Providing High-Quality Zinc Coatings (Hot-Dip)3
A767/A767M Specification for Zinc-Coated Galvanized Steel Bars for Concrete Reinforcement4
A780Practice for Repair of Damaged and Uncoated Areas of Hot-Dip Galvanized Coatings3
A902Terminology Relating to Metallic Coated Steel Prod-ucts3
B6Specification for Zinc5
B487Test Method for Measurement of Metal and Oxide Coating Thickness by Microscopical Examination of a Cross Section6
B602Test Method for Attribute Sampling of Metallic and Inorganic Coatings6
vivo手机主题E376Practice for Measuring Coating Thickness by
1This specification is under the jurisdiction of ASTM Committee A05on Metallic Coated Iron and Steel Products and is the direct responsibility of Subcommittee A05.13on Structural Shapes and Hardware Specifications.
Current edition approved October10,2002.Published December2002.Origi-nally published as A123–28T.Last previous edition A123–01a.
2Annual Book of ASTM Standards,V ol01.02.
3Annual Book of ASTM Standards,V ol01.06.
4Annual Book of ASTM Standards,V ol01.04.
5Annual Book of ASTM Standards,V ol02.04.
火狐翻译6Annual Book of ASTM Standards,V ol02.05. 1
Copyright©ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA19428-2959,United States.会议现场
Magnetic-Field or Eddy-Current(Electromagnetic)Test Methods7
3.Terminology(See Fig.1)
3.1Definitions:
3.1.1The following terms and definitions are specific to this specification.Terminology A902contains other terms and definitions relating to metallic-coated steel products.
3.2Definitions of Terms Specific to This Standard:
3.2.1average coating thickness,n—the average of three specimen coating thickness.
3.2.2black,adj—denotes the condition of not galvanized or otherwi coated.For purpos of this specification the word “black”does not refer to the color or condition of surface,or to
a surface deposit or contamination.
3.2.3coating thickness grade,n—the numerical value from Table1at the interction of a material category and a thickness range.
3.2.4gross dross inclusions,n—the iron/zinc intermetallics prent in a galvanized coating in a form other thanfinely disperd pimples.
3.2.
4.1Discussion—The inclusions would create an ex-pod steel spot if they were removed from the coating.The inclusions are raid surfaces and are easily knocked off
7Annual Book of ASTM Standards,V ol03.03.
3.2.6multi-specimen article,n—a unit of product who surface area is greater than160in.2[100000mm2].For thickness testing purpos,articles who surface area is greater than160in.2are subdivided into three continuous local ctions,nominally equal in surface area,each of which constitutes a specimen.In the ca of any such local ction containing more than one material category or steel thickness range as delineated in Table1,that ction will contain more than one specimen(e Fig.1).
3.2.7sample,n—a collection of individual units of product from a single lot lected in accordance with Section7,and intended to reprent that lot for acceptance.If a sample is taken as reprenting the lot for acceptance,the sample shall be taken at random from the lot without regard to the perceiv
ed quality or appearance of any individual unit in the lot being sampled.The sample consists of one or more test articles. 3.2.8single-specimen article,n—a unit of product who surface area is equal to or less than160in.2[100000mm2]or that is centrifuged or otherwi similarly handled in the galvanizing process to remove excess galvanizing bath metal (free zinc).For thickness testing purpos,the entire surface area of each unit of product constitutes a specimen.In the ca of any such article containing more than one material category or steel thickness range as delineated in Table1,that article will contain more than one specimen(e Fig.1).
3.2.9specimen,n—the surface of an individual test article or a portion of a test article,upon which thickness measure-ments are to be performed,which is a member of a lot,or a member of a sample reprenting that lot.For magnetic thickness measurements,specimen excludes any area of the surface which is subject to process(such asflame cutting, machining,threading,etc.)that can be expected to result in surface conditions not reprentative of the general surface condition of the test article,or is disqualified by the measure-ment method.The minimum average coating thickness grade for any specimen shall be one coating grade below that required for the appropriate material category and thickness in Table1.For a unit of product who surface area is equal to or less than160in.2[100000mm2],the entire surface area of each test article constitutes a specimen.In the c
a of an article containing more than one material category or steel thickness range as delineated in Table1,that article will contain more than one specimen,as appropriate(e Fig.1).a member of the sample and that is examined for conformance to a part of this specification.
4.Ordering Information
4.1Orders for coatings provided under this specification shall include the following:
4.1.1Quantity(number of pieces to be galvanized)and total weight.
4.1.2Description(type and size of products)and weight.
4.1.3ASTM specification designation and year of issue.
4.1.4Material identification(e
5.1)and surface condition or contamination.
4.1.5Sampling plan,if different from7.3.
4.1.6Special test requirements(e8.1).
4.1.7Special requirements(special stacking,heavier coat-ing weight,etc.).
4.1.8Tagging or piece identification method.
5.Materials and Manufacture
脚后跟干裂是什么原因5.1Steel or Iron—The specification,grade,or designation and type and degree of surface contamination of the iron or steel in articles to be galvanized shall be supplied by the purchar to the hot-dip galvanizer prior to galvanizing.怎样自己交社保
N OTE2—The prence in steels and weld metal,in certain percentages, of some elements such as silicon,carbon,and phosphorus tends to accelerate the growth of the zinc-iron alloy layer so that the coating may have a mattefinish with little or no outer zinc layer.The galvanizer has only limited control over this condition.The mass,shape,and amount of cold working of the product being galvanized may also affect this condition.Practice A385provides guidance on steel lection and discuss the effects of various elements in steel compositions(for example,silicon),that influence coating weight and appearance.
5.2Fabrication—The design and fabrication of the product to be galvanized are the responsibilities of
the designer and the fabricator.Practices A143,A384,and A385provide guidance for steel fabrication for optimum hot dip galvanizing and shall be complied with in both design and fabrication.Consultation between the designer,fabricator,and galvanizer at appropriate stages in the design and fabrication process will reduce future problems.
5.3Castings—The composition and heat treatment of iron and steel castings shall conform to specifications designated by the purchar.Some types of castings have been known to
TABLE1Minimum Average Coating Thickness Grade by Material Category
show potential problems with predisposition to being em-brittled during the normal thermal cycle of hot-dip galvanizing.It is the responsibility of the purchar to heat treat or otherwi allow for the possibility of such embrittling phenom-ena.The requirements for malleable iron castings to be galvanized shall be as stated in Specification A 47.
5.4Zinc —The zinc ud in the galvanizing bath shall conform to Specification B
6.If a zinc alloy is ud as the primary feed to the galvanizing bath,then the ba material ud to make that alloy shall conform to Specification B 6.5.5Bath Composition —The molten metal in the w
orking volume of the galvanizing bath shall contain not less than an average value of 98.0%zinc by weight.
N OTE 3—The galvanizer may choo to add trace amounts of certain elements (for example,aluminum,nickel,and tin)to the zinc bath to help in the processing of certain reactive steels or to enhance the cosmetic appearance of the finished product.The u of the trace elements is permitted provided that the bulk chemistry of the galvanizing bath is at least 98.0%zinc by weight.The elements can be added to the galvanizing bath as part of a pre-alloyed zinc feed,or they can be added to the bath by the galvanizer using a master feed alloy.
6.Coating Properties
6.1Coating Thickness —The average thickness of coating for all specimens tested shall conform to the requirements of Table 1for the categories and thickness of the material being galvanized.Minimum average thickness of coating for any individual specimen is one coating grade less than that required in Table 1.Where products consisting of various material thickness or categories are galvanized,the coating thickness grades for each thickness range and material category of material shall be as shown in Table 1.In the ca of orders in SI units,the values in Table
1,shall be applicable as metric units in micrometres.In the ca of orders in inch-pound units,the measured value shall be converted to coating grade units by the u of Table 2.The specification of coating thickness heavier than tho required by Table 1shall be subject to mutual agreement between the galvanizer and the purchar.(Fig.2is a graphic reprentation of the sampling and specimen delineation steps,and Fig.3is a graphic reprenta-tion of the coating thickness inspection steps.)
6.1.1For articles who surface area is greater than 160in.2[100000mm 2](multi-specimen articles),each test article in the sample must meet the appropriate minimum average coating thickness grade requirements of Table 1,and each specimen coating thickness grade comprising that overall
average for each test article shall average not less than one coating grade below that required in Table 1.
6.1.2For articles who surface area is equal to or less than 160in.2[100000mm 2](single-specimen articles),the average of all test articles in the sample must meet the appropriate minimum average coating thickness grade requirements of Table 1,and for each test article,its specimen coating thickness shall be not less than one coating grade below that required in Table 1.
6.1.3No individual measurement,or cluster of measure-ments at the same general location,on a test specimen shall be cau for rejection under the coating thickness requirements of this specification provided that when tho measurements are averaged with the other disperd measurements to determine the specimen coating thickness grade for that specimen,the requirements of 6.1.1or 6.1.2,as appropriate are met.
N OTE 4—The coating thickness grades in Table 1reprent the mini-mum value obtainable with a high level of confidence for the ranges typically found in each material category.While most coating thickness will be in excess of tho values,some materials in each category may be less reactive (for example,becau of chemistry or surface condition)than other materials of the steel category spectrum.Therefore,some articles may have a coating grade at or clo to the minimum requirement shown in Table 1.In such cas,the precision and accuracy of the coating thickness measuring technique should be taken into consideration when rejecting such articles for coating thickness below that required by this specification.Purchars desiring a guarantee of heavier coatings than the minimum thickness shown herein should u the special requirements (e 4.1.6)to specify coating thickness grades higher than tho shown in
TABLE 2Coating Thickness Grade A
Coating Grade mils oz/ft 2µm g/m 235 1.40.83524545 1.8 1.04532050 2.0 1.25035555 2.2 1.35539060 2.4 1.46042565 2.6 1.56546075 3.0 1.77553080 3.1 1.98056585 3.3 2.085600100
3.9
2.3
100
705
A
The values in micrometres (µm)are bad on the Coating Grade.The other values are bad on conversions using the following formulas:mils =µm 30.03937;oz/ft 2=µm 30.02316;g/m 2=µm 37.067.
N OTE 1—Each specimen compris nominally one third of the total surface area of the article.A minimum of five measurements should be made within the volume of each specimen,as widely dispe
rd within that volume as is practical,so as to reprent as much as possible,the general coating thickness within that specimen volume.
FIG.2Articles Made of Many
Components
A 123/A 123M –02
4
Table1.In addition,the purchar should anticipate the need for test batches or extra preparation steps,or both,such as blasting before galvanizing or other methods,to attempt to reach the higher requirements with consistency.Some higher-than-standard thickness may be imprac-tical or unattainable.
6.2Finish—The coating shall be continuous(except as provided below),and as reasonably smooth an
d uniform in thickness as the weight,size,shape of the item,and necessary handling of the item during the dipping and draining operations at the galvanizing kettle will permit.Except for local excess coating thickness which would interfere with the u of the product,or make it dangerous to handle(edge tears or spikes), rejection for nonuniform coating shall be made only for plainly visible excess coating not related to design factors such as holes,joints,or special drainage problems(e Note6).Since surface smoothness is a relative term,minor roughness that does not interfere with the intended u of the product,or roughness that is related to the as-received(un-galvanized) surface condition,steel chemistry,or steel reactivity to zinc shall not be grounds for rejection(e Note7).Surface conditions related to deficiencies related to design,detailing,or fabrication as addresd by Practice A385shall not be grounds for rejection.The zinc coating on threaded components of articles galvanized under this specification shall conform to that required in Specification A153/A153M.Surfaces that remain uncoated after galvanizing shall be renovated in accor-dance with the methods in Practice A780unless directed by the purchar to leave the uncoated areas untreated for sub-quent renovation by the purchar.
6.2.1Each area subject to renovation shall be1in.[25mm] or less in its narrowest dimension.
6.2.2The total area subject to renovation on each article shall be no more than1⁄2of1%of the accessib
le surface area to be coated on that article,or36in.2per short ton[256cm2per metric ton]of piece weight,whichever is less.
N OTE5—Inaccessible surface areas are tho which cannot be reached for appropriate surface preparation and application of repair materials as described in Practice A780.Such inaccessible areas,for example,would be the internal surfaces of certain tanks,poles,pipes,tubes,and so forth.
6.2.3The thickness of renovation shall be that required by the thickness grade for the appropriate material category and thickness range in Table1in accordance with the requirements of 6.1,except that for renovation using zinc paints,the thickness of renovation shall be50%higher than that required by Table1,but not greater than4.0mils.
6.2.4When areas requiring renovation exceed the criteria previously provided,or are inaccessible for repair,the coating shall be rejected.
N OTE6—The requirements for thefinish of a galvanized product address themlves to a visual type of inspection.They do not address the matter of measured coating thickness variations that can be encountered becau of different steels or different thickness of a given steel being ud in an asmbly.
N OTE7—Items which are prepared for galvanizing by abrasive clean-ing will generally develop a thicker coating with a moderately rougher surface.
6.3Threaded Components in Asmblies—The zinc coating on external threads shall not be subjected to a cutting,rolling, orfinishing tool operation,unless specifically authorized by the purchar.Internal threads are not prohibited from being tapped or retapped after galvanizing.Coatings shall conform to the requirements of Specification A153/A153M.
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6.4Appearance—Upon shipment from the galvanizing fa-cility,galvanized articles shall be free from uncoated areas, blisters,flux deposits,and gross dross inclusions.Lumps, projections,globules,or heavy deposits of zinc which will interfere with the intended u of the material will not be permitted.Plain holes of1⁄2-in.[12.5-mm]diameter or more shall be clean and reasonably free from excess zinc.Marks in the zinc coating caud by tongs or other items ud in handling the article during the galvanizing operation shall not be cau for rejection unless such marks have expod the ba metal and the bare metal areas exceed allowable maximums from6.2.1and6.2.2.The pieces shall be handled so that after galvanizing they will not freeze together on cooling.
N OTE8—Depending upon product design or material thickness,or both,filming or excess zinc buildup in plain holes of less than1⁄2-in.
