1、Designation: A 918 06Standard Specification forSteel Sheet, Zinc-Nickel Alloy Coated by the ElectrolyticProcess for Applications Requiring Designation of theCoating Mass on Each Surface1This standard is issued under the fixed designation A 918; the number immediately following the designation indica
2、tes the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This specification covers zinc-nickel allo
3、y coatingsapplied by the electrolytic process to hot-rolled and cold-rolledsteel sheet. The coating has a smooth, spangle-free surface. Thezinc-nickel-coated sheet covered in this specification is pro-duced in a range of coating masses to provide coatings that arecompatible with the anticipated serv
4、ice life required. Thecoating mass varies, from very thin coatings that are usuallypainted to provide good service, to relatively heavy masses thatprovide good corrosion resistance in the bare (unpainted)condition. The composition range is from 9 to 16 % nickel, byweight, with the balance being zinc
5、.1.2 The product shall be coated on one or both surfaces withequal or differential coating masses on the two surfaces. Sheetcoated with equal coating masses on each surface has similarlevels of corrosion protection on each surface. Often, however,a higher level of corrosion protection is required on
6、 one surfacethan is required on the other. In these situations, one surfaceshall be specified with a heavier coating mass than the other.Either surface, when specified to be painted, will provideadditional corrosion protection as compared to an unpaintedsurface.1.3 This coating process has essential
7、ly no effect on the basemetal mechanical properties, and use is permitted on any gradeof hot- or cold-rolled steel sheet. The coated sheet is availableas Commercial Steel (CS), Drawing Steel (DS), Deep DrawingSteel (DDS), Extra-Deep Drawing Steel (EDDS), StructuralSteel (SS), High-Strength Low-Alloy
8、 Steel (HSLAS), High-Strength Low-Alloy Steel with Improved Formability(HSLAS-F), Solution-Hardened Steel (SHS), or Bake-Hardenable Steel (BHS).1.4 The values stated in SI units are to be regarded as thestandard.2. Referenced Documents2.1 ASTM Standards:2A 754/A 754M Test Method for Coating Weight (
9、Mass) ofMetallic Coatings on Steel by X-Ray FluorescenceA 917 Specification for Steel Sheet, Coated by the Electro-lytic Process forApplications Requiring Designation of theCoating Mass on Each Surface (General Requirements)E 1659 Test Methods for Coating Weight and ChemicalAnalysis of Zinc-Nickel A
10、lloy Electrolytically Coated onSteel Sheet3. Classification3.1 Coatings shall be designated as in Specification A 917.The letter N shall be used to designate zinc-nickel coatings.4. Ordering Information4.1 Orders for products to this specification shall include thefollowing information, as necessary
11、 to adequately describe thedesired product:4.1.1 Name of product (electrolytic zinc-nickel alloy-coatedsteel sheet).4.1.2 ASTM designation and year of issue.4.1.3 Base metal type (hot rolled or cold rolled).4.1.4 Base metal designation Commercial Steel (CS),Drawing Steel (DS), Deep Drawing Steel (DD
12、S), Extra-DeepDrawing Steel (EDDS), High-Strength Low-Alloy Steel(HSLAS), High-Strength Low-Alloy with Improved Formabil-ity (HSLAS-F), Solution-Hardened Steel (SHS), or Bake-Hardenable Steel (BHS).4.1.5 Formability type, strength, grade, or class, or combi-nation thereof, as required for structural
13、 or high-strengthlow-alloy steels.4.1.6 Coating designation (see 3.1).4.1.7 Surface treatments required (see Note 1).1This specification is under the jurisdiction of ASTM Committee A05 onMetallic-Coated Iron and Steel Products and is the direct responsibility ofSubcommittee A05.11 on Sheet Specifica
14、tions.Current edition approved Nov. 1, 2006. Published December 2006. Originallyapproved in 1993. Last previous edition approved in 2005 as A 918 00 (2005).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of AST
15、MStandards volume information, refer to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.NOTE 1Steel sheet is ava
16、ilable without surface treatment (dry) or withsurface treatments designated as chemical treatment, oiled, or phos-phatized. Unless otherwise specified sheet is furnished oiled.4.1.8 Dimensions (show thickness (minimum or nominal),width, and length, if cut lengths).4.1.9 Coil size (must include insid
17、e diameter, outside diam-eter, and maximum coil weight).4.1.10 Application (part name and description).4.1.11 Special requirements, if applicable.4.1.12 Certification, if required, heat analysis and mechani-cal property report.5. Coating Mass5.1 Coating mass shall conform to the requirements forcoat
18、ing designation (mass and type) as given in SpecificationA 917 and in Table 1 for the specific coating designation. Themass of the coating is the single spot value on each surface ofthe sheet in grams per square metre.5.2 Coating Mass Tests:5.2.1 Test Methods E 1659 describes the weigh-strip-weighme
19、thod is a destructive test that determines coating mass bymeasuring the difference in weight between a coated and astripped (uncoated) sample. If one surface is protected suitablyduring the initial stripping, coating mass can be determined foreach surface independently. Conversion of the coating mas
20、s tocoating thickness is possible only if the density of the coatingis known precisely.5.2.2 Coating thickness measurements by X-ray fluores-cence (see Test MethodA 754/A 754M) is a nondestructive testmethod that determines coating mass by converting X-rayfluorescence measurements to coating mass va
21、lues. This testmethod is readily adaptable to the continuous monitoring ofcoating mass during coating. Thus, modern electroplatingfacilities are frequently equipped with X-ray fluorescencegauges that provide feedback to control the coating mass.These devices are used as a basis for determining the s
22、uitabilityfor shipment provided that they have been calibrated properlyin accordance with Test Method A 754/A 754M.5.2.3 Sampling and retests for coating mass determinationsshall be as given in Specification A 917.5.2.4 The referee test methods for measurement of thecoating mass are Test Methods E 1
23、659.6. Coating Composition6.1 Coating Composition Tests:6.1.1 The test for chemical determination of the coatingcomposition by atomic absorption spectroscopy is a destructivetest that requires stripping of the coating from a specimen. Ifone surface is protected suitably during the stripping, coating
24、compositions can be determined for each surface indepen-dently.6.1.2 Sampling and retests for coating composition determi-nations shall be as given in Specification A 917.6.1.3 The referee test methods for determination of thecoating composition are Test Methods E 1659.7. Keywords7.1 electrolytic co
25、ating; steel sheet-zinc nickel alloy coated;zinc-nickel alloy coated; zinc-nickel alloy coated steel sheetSUMMARY OF CHANGESCommittee A05 has identified the location of selected changes to this standard since the last issue(A 918 00(2005) that may impact the use of this standard. (November 1, 2006)(
26、1) Revised 1.3 and 4.1.4 to include Solution-Hardened Steel(SHS) and Bake-Hardenable Steel (BHS) designations.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised
27、 that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either rea
28、pproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If yo
29、u feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual
30、 reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).TABLE 1 Coating Masses for Steel Sheet, Zinc-Nickel Alloy-Coated by the Electrolytic ProcessACoating DesignationBSurface, g/m2Minimum Maximum00N no coating no coating20N 20 4030N 30 5040N 40 6050N 50 70AThe product shall be coated on at least one surface; therefore, the combination00/00 shall not be specified.BSee Specification A 917.A918062
