1、Designation: A1059/A1059M 08 (Reapproved 2013)Standard Specification forZinc Alloy Thermo-Diffusion Coatings (TDC) on SteelFasteners, Hardware, and Other Products1This standard is issued under the fixed designation A1059/A1059M; the number immediately following the designation indicates theyear of o
2、riginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers the general requirements forprotec
3、tive zinc coatings (hereinafter referred to as the coatings)to be applied by the thermo-diffusion coating (TDC) method,to various products made of carbon steel, including low andhigh tensile parts as well as of wrought iron, sintered ironsteel-powder and various steel and stainless alloys. TDC iscar
4、ried out by immersing the parts in a zinc alloy powder atelevated temperature for a period of time, causing a metallur-gical diffusion process of zinc and iron. Further processingmay be added, such as, passivation, topcoat application, paintapplication, etc.1.2 This specification is applicable to or
5、ders in eitherinch-pound units (as A1059) or in SI units (as A1059M).Inch-pound units and SI units are not necessarily exactequivalents. Within the text of this specification and whereappropriate, SI units are shown in brackets. Each system shallbe used independently of the other without combining v
6、alues inany way. In the case of orders in SI units, all testing andinspection shall be done using the metric equivalent of the testor inspection method as appropriate. In the case of orders ininch-pound units, such shall be stated to the applicator whenthe order is placed.1.3 This standard does not
7、purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:
8、2A90/A90M Test Method for Weight Mass of Coating onIron and Steel Articles with Zinc or Zinc-Alloy CoatingsA385 Practice for Providing High-Quality Zinc Coatings(Hot-Dip)A700 Practices for Packaging, Marking, and Loading Meth-ods for Steel Products for ShipmentA902 Terminology Relating to Metallic C
9、oated Steel Prod-uctsB487 Test Method for Measurement of Metal and OxideCoating Thickness by Microscopical Examination ofCross SectionD521 Test Methods for Chemical Analysis of Zinc Dust(Metallic Zinc Powder)D6386 Practice for Preparation of Zinc (Hot-Dip Galva-nized) Coated Iron and Steel Product a
10、nd HardwareSurfaces for PaintingE376 Practice for Measuring Coating Thickness byMagnetic-Field or Eddy-Current (Electromagnetic) Test-ing MethodsF1789 Terminology for F16 Mechanical FastenersF2329 Specification for Zinc Coating, Hot-Dip, Require-ments for Application to Carbon and Alloy Steel Bolts,
11、Screws, Washers, Nuts, and Special Threaded FastenersF2674 Specification for Zinc Coating, Hot-Dip, Require-ments for Application to Carbon and Alloy Steel Bolts,Screws, Washers, Nuts, and Special Threaded FastenersMetric (Withdrawn 2011)33. Terminology3.1 The following terms and definitions are spe
12、cific to thisspecification. Terminology A902 contains other terms anddefinitions relating to metallic-coated steel products. Terminol-ogy F1789 contains other terms and definitions relating tomechanical fasteners.3.2 Definitions of Terms Specific to This Standard:3.2.1 thermo-diffusion coatinga proc
13、ess where the steelproduct is heated in close contact with zinc powder or zincmixture.3.2.2 thermo-diffusion coatinga coating made by thermo-diffusion coating process, consisting of zinc/iron alloys.1This specification is under the jurisdiction of ASTM Committee A05 onMetallic-Coated Iron and Steel
14、Products and is the direct responsibility ofSubcommittee A05.13 on Structural Shapes and Hardware Specifications.Current edition approved May 1, 2013. Published May 2013. Originallyapproved in 2008. Last previous edition approved in 2008 as A1059/A1059M08.DOI: 10.1520/A1059_A1059M-08R13.2For referen
15、ced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onww
16、w.astm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.3 zinc powderthe coating material used to providecorrosion protection to steel.3.2.4 zinc mixturea combination of zinc powder and othermetallic materials to be used as a c
17、oating material in the TDCprocess.4. Ordering Information4.1 Orders for coatings provided under this specificationshall include the following:4.1.1 Quantity (number of pieces to be coated) and totalweight.4.1.2 Description (type and size of products) and weight.4.1.3 ASTM specification designation a
18、nd year of issue.4.1.4 Material identification (see 5.1) and surface conditionor contamination.4.1.5 Sampling plan, if different from Section 8.4.1.6 Special test requirements, if different from Section 9(see 9.1).4.1.7 Special requirements (special stacking, heavier coat-ing weight, etc.).4.1.8 Tag
19、ging or piece identification method.4.2 Additional InformationAdditional information may berequired in certain circumstances. In these cases the purchaserwill furnish the applicator with the following additional infor-mation:4.2.1 Any likely effects on the metallurgical properties ofthe base materia
20、l caused by processing temperatures of up to1092F 500C.4.2.2 Determination of areas considered as significant sur-faces. This should be done by drawings or by providingsamples with suitable markings.4.2.3 Any critical thickness tolerances, such as when boltsand nuts are used. This should be done on
21、the productsdrawing or on the purchase order.4.2.4 Any special pre-treatment requirements or the exis-tence of other materials, lubricants, stripping materials, pre-existing corrosion, etc.4.2.5 Whether quality certificate is required or not.5. Materials and Manufacture5.1 Requirements to design of
22、the products to be coatedwith zinc are detailed in Practice A385. The following provi-sions are necessary to produce a high quality coating.5.1.1 The products to be coated with zinc include parts andassemblies of various sizes: presswork, forged, cast, machinedproducts (nuts, washers, bolts, nails,
23、chains, small roundbillets, blanks for plumbing fixtures, etc.). When coating isapplied to long-length parts (pipes, rods), the appropriateproduction equipment is required.5.1.2 The products shall have neither pockets nor closedcavities. All cavities shall be available for applying the coatingof dif
24、fusion mixture. Should it be impossible to apply thecoating to individual portions of surface of the article, thedocuments shall specify if the coating is allowed to be absentin these cavities.5.1.3 The fasteners to be coated with zinc shall meet therequirements of standards in force, for the fasten
25、ers, andaccompanied with certificates from manufacturers.5.1.4 The products (parts) containing soft solder or resinscan not be coated with zinc.5.1.5 For FastenersThe maximum deviations of threadsprior to application of the coating shall comply with thestandards for threads. An additional gap for th
26、e coating forexternal and internal threads separately or for both threads atthe same time, is to be provided, if the coating with increasedthickness is to be applied. Requirements for fasteners to bethermal diffusion coated with zinc are found in SpecificationsF2329 and F2674.5.2 Requirements for ma
27、terial and surface of substrate:5.2.1 This is applied to products of standard-quality carbonsteel, high-quality structural carbon and low-carbon steel, aswell as low-alloyed steel, stainless steels, pig iron and copper.5.2.2 The following defects are not allowed on the surfacesof the parts:5.2.2.1 R
28、olled-in scale, burrs;5.2.2.2 Separation into layers and cracks including thosearising from pickling, polishing and other treatment;5.2.2.3 Corrosion damages, pores, and holes.5.2.3 The surfaces of cast and forged products shall be freeof blow and shrink holes, slag, and flux contamination.5.2.4 The
29、 surfaces of the parts of hot-rolled metal shall becleaned from scale, pickling sludge, products of corrosion ofthe base metal, and other contamination.5.2.5 After machining, the surfaces of the parts shall be freeof visible layer of grease, emulsion, metallic chips, burrs, dustand products of corro
30、sion, and implantation of foreign metalparticles.5.2.6 Sharp corners and edges of the products except forthose required for technological reasons shall be machined to aradius of at least 0.001 in. 0.3 mm.5.2.7 After heat treatment, the surfaces of the parts shall befree of blow holes, corrosion cent
31、ers, separation into layers,and buckling.5.2.8 Welds, soldered and brazed joints on the parts shall bescraped bright and continuous over the whole perimeter.5.2.9 Prior to applying the coating, the surface of the partshall be degreased (chemically or thermally), cleaned bypickling or abrasive blasti
32、ng.5.2.10 The degree of cleanness of the surface shall be inaccordance with Practice D6386.5.2.11 The term for storage of the parts with the surfaceprepared for coating with zinc shall not exceed 24 hours underconditions excluding the precipitation of a condensate.5.2.12 For applying coatings, the z
33、inc powder with humid-ity of not more than 1.5 % in accordance with Test MethodsD521 shall be used.6. Chemical Composition6.1 The method described results in the formation of iron-zinc compound layers known as Gamma (Solid Zn ions insideFe substrate), Delta (Fe11Zn40), and Zeta (FeZn7), excludingthe
34、 external Eta layer of pure free zinc.6.2 The zinc mixture used in the thermo-diffusion coatingprocess shall contain a mass fraction not less than 94 % ofmetallic zinc and total impurities (other than Zinc oxide) of notmore than 2 % mass fraction.A1059/A1059M 08 (2013)26.3 It should be noted that th
35、ere is evidence this coating issubject to premature red staining in atmospheric and acceler-ated test environments; however, this staining has been foundnot to be associated with corrosion of the substrate steel, butrather superficial oxidation of the zinc/iron ions present on thesurface.7. Workmans
36、hip, Finish, and Appearance7.1 Appearance of the coating:7.1.1 The coating shall be flat gray, smooth, and reasonablyuniform. Smoothness of surface is a relative term. Minorroughness that does not interfere with the intended use of thepart, or roughness that is related to the as-received (un-coated)
37、surface condition of the part, shall not be grounds for rejection.7.1.2 The coating shall be free of swellings, blow holes,cuts, flaking, and embedded quartz sand.7.1.3 The presence of dark gray spots (variation in the colorof the coating without variation in its thickness) not more than5 % of the t
38、otal surface of the product is allowed on thecoating.7.1.4 The presence of surface scratches, marks from contactof the part with one another, contact with measuring tools, etc.,without damage to the coating, which would cause exposure ofthe base metal, is allowed.7.1.5 The presence of residual proce
39、ss mixture on thesurface of the part is not allowed.7.1.6 The thickness of the coating depending on the condi-tions of operations of the product shall be specified in thestandards of specification for the product in accordance withTable 1.8. Sampling8.1 Test specimens shall be selected randomly from
40、 eachinspection lot.8.2 The method of selection and sample size shall be agreedupon between the applicator and the purchaser. Otherwise, thesample size selected from each lot shall be as follows:Batch Size (Pieces) Sample Size1to3 All4to500 3501 to 1200 51201 to 3200 83201 to 10 000 13Above 10 000 2
41、09. Number of Tests and Retests9.1 The zinc coating applied shall be tested for appearanceand thickness.9.2 Each lot of parts coated with zinc shall be presented fortesting. A lot shall be considered as a group of articles of thesame type and size coated with zinc within the same productioncycle.9.3
42、 Approximately 10 % of articles per lot and each articlein case of single-unit production shall be examined for appear-ance.9.4 At least three articles per lot shall be tested for thicknessof the coating.9.5 When using the metallographic (arbitration) method, itis allowed to test the coating thickne
43、ss on one part per lot.9.6 The coating thickness shall be tested prior to theadditional treatment of the coating (applying preservationlubricants, etc.). This measurement shall be taken on a non-threaded section of the part.9.7 The coating thickness on the threaded portion of a boltshall not be test
44、ed but shall be ensured by the correctness of thecoating application technology. When developing the coatingprocess it is recommended to take into account the ISOrequirements for threaded fasteners.9.8 The checked thickness of the coating shall be acceptedas an arithmetical mean of the measured valu
45、es.9.9 Should the results of the measuring of the test control beunsatisfactory, the test shall be repeated on double quantity ofparts.10. Specimen Preparation10.1 Specimens for testing should not go through anycleaning process and should be tested as is after the finalcoating process (including pas
46、sivation and or other top coats).11. Test Methods11.1 Coating appearance check: The coating appearanceshall be checked visually with an unaided eye from the distanceof 10 in. 25 cm from the surface. The luminance shall be atleast 300Lx.11.2 Coating thickness testing:TABLE 1 Thickness or Weight Mass
47、of Zinc Coating for Various Coating ClassesCoating Class Weight Mass of Coating, oz/ft2(g/m2)ofSurface, MinimumCoating Thickness, mils (m), Minimum130 3.02 (922) 5.14 (130)110 2.50 (765) 4.33 (110)90 2.05 (627) 3.54 (90)80 1.82 (557) 3.15 ( 80)70 1.59 (487) 2.76 (70)65 1.48 (453) 2.56 (65)55 1.25 (3
48、83) 2.17 (55)50 1.14 (348) 1.97 (50)45 1.02 (313) 1.77 (45)40 0.91 (278) 1.57 (40)25 0.57 (174) 0.98 (25)12 0.27 (84) 0.47 (12)A1059/A1059M 08 (2013)311.2.1 Magnetic Method:11.2.1.1 The method is based on the registration of variationin the magnetic resistance depending on the coating thicknessin ac
49、cordance with Practice E376. The magnetic thicknessgauges shall be used as measuring instruments.11.2.1.2 The arithmetic mean of at least three measuredvalues at edges and center of the surface of one article to becontrolled shall be considered as the result of the coatingthickness measurement.11.2.2 Metallographic Method (Arbitration) The methodis based on the measurement of the coating thickness on thecross-section metallographic specimen using metallographicmicroscopes of various types in accordance with Test MethodB487. The specimen shall be cut from a
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