ASTM A902-2008a Standard Terminology Relating to Metallic Coated Steel Products.pdf

1、Designation: A 902 08aStandard TerminologyRelating to Metallic Coated Steel Products1This standard is issued under the fixed designation A 902; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in

2、parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This standard is a compilation of terminology related tometallic coatings used in the steel industry, and to the steel onwhich the coatings are

3、applied. Terms that are generallyunderstood or adequately defined in other readily availablesources are not included.1.2 When a term is used in an ASTM document for whichCommittee A05 is responsible it is included herein only whenjudged, after review by Subcommittee A05.18, to be a gener-ally usable

4、 term.1.3 Definitions that are identical to those published by otherASTM committees or other standards organizations are iden-tified with the ASTM standard designation (for example,Terminology B 374) or with the abbreviation of the name ofthe organization.1.4 A definition is a single sentence with a

5、dditional infor-mation included in notes. The year the definition was adopted,or the year of latest revision, is appended. The responsiblesubcommittee reviews the definition for each term at five-yearintervals, and prepares revisions as needed.2. Referenced Documents2.1 ASTM Standards:2A 641/A 641M

6、Specification for ZincCoated (Galvanized)Carbon Steel WireB 374 Terminology Relating to ElectroplatingD 6386 Practice for Preparation of Zinc (Hot-Dip Galva-nized) Coated Iron and Steel Product and HardwareSurfaces for PaintingD 7396 Guide for Preparation of New, Continuous Zinc-Coated (Galvanized)

7、Steel Surfaces for Painting3. Terminology3.1 Definitions:aluminized coating, na coating on steel consisting of eithercommercially-pure aluminum (Type 2) or aluminum-siliconalloy (Type 1), applied by the hot-dip process. (2005)barb, nas related to barbed wire, a short length of wire, withexposed ends

8、 cut on a bias to produce sharp points. (1995)barbed wire, na fabricated wire product consisting of twoline wires twisted to form a two-wire strand, into which2-point or 4-point barbs are tightly wrapped and locked intoplace at specified intervals. (1995)base metal, nas related to metallic-coated st

9、eel, the steel towhich the coating is applied, as distinguished from thecoating metal. (1990)batch coating, nof metallic coated steel products, theprocess of discontinuous-sequential passage of steel articlesthrough the various steps of the coating process, such as,cleaning, pickling, fluxing, and c

10、oating. (1995)breaking strength, n as related to wire, the maximum forcedeveloped prior to fracture during tension testing of wire andwire products.DISCUSSIONIn testing of stranded wire products, the maximumforce may be developed after fracture of one or more individual wires.(1993)carbon steel, nst

11、eel having a maximum carbon content of2.0 % and a composition conforming to the following: (1)nominimum content is specified for chromium, cobalt, colum-bium (niobium), molybdenum, nickel, titanium, tungsten,vanadium, zirconium, or any other element added to obtaina desired alloying effect; (2) the

12、specified minimum andmaximum values for copper do not exceed 0.35 % and0.60 %, respectively; (3) the specified maximum for any ofthe following elements does not exceed these percentages:manganese 1.65 %, silicon 0.60 %, columbium (niobium)0.015 %, vanadium 0.008 %, boron 0.0008 %, or titanium0.025 %

13、; and (4) the incidental content of the followingelements does not exceed these percentages: nickel, 0.20 %;chromium, 0.15 %; and molybdenum, 0.06 %.DISCUSSIONCarbon steels typically contain small quantities ofcertain residual elements from the feed materials. When the quantity ofsuch retained eleme

14、nts exceeds the values listed in (4) above, thecharacteristics of the steel may differ from that of carbon steel withoutthose elements to a degree that the steel may be unsatisfactory for theintended use. The composition limits stated in this definition shall notapply to stabilized steel. (2005)1Thi

15、s terminology is under the jurisdiction of ASTM Committee A05 onMetallic-Coated Iron and Steel Products and is the direct responsibility ofSubcommittee A05.18 on Editorial and Terminology.Current edition approved Nov. 1, 2008. Published November 2008. Originallyapproved in 1990. Last previous editio

16、n approved in 2008 as A 902 - 08.2For referenced 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.1*A Summary of Changes secti

17、on appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.chemical treatment, na passivating surface protectant nor-mally applied to metallic coatings to retard the formation ofcorrosion products during sh

18、ipment and storage (storagestain).DISCUSSIONThe corrosion-inhibiting characteristics of chemicaltreatments are limited. If chemically-treated material becomes wet inshipment or storage, the product should be used or dried immediately.Some types of chemical treatments may be inappropriate in certaina

19、pplications because of possible undesirable effects further processing,such as phosphatizing, spot welding, or painting. (2007)continuous coating, nof metallic coated steel products, theprocess of uninterrupted passage of long lengths of steelproducts, usually steel sheet, tube, pipe, or wire, throu

20、gh thevarious processing steps such as cleaning, annealing, andcoating.DISCUSSIONContinuous coating involves the use of equipment thatis capable of joining long lengths of product without stoppage of thecoating process. Continuous coating of preformed tube or pipe islimited to the outer surface, sin

21、ce the coating material cannot besupplied to the inner surface. (2006)delamination, nas related to metallic coated steel, theseparation of a coating (either full or partial thickness) fromunderlying layers; the separation can occur in small localizedareas or large areas of surface.DISCUSSIONFlaking,

22、 peeling, and spalling are colloquial termssometimes used to describe the separation. (1997)differentially coated sheet, nmetallic coated sheet withspecified difference in weight (mass) of metallic coating oneach of the two surfaces. (2006)electrolytic process, nthe application of a metallic coating

23、on a steel product by passing an electric current through achemical solution in which the product is immersed; thecoating may be applied in a continuous process or a batchprocess. (1995)extra smooth sheet, nproduct produced by cold rolling themetallic coated sheet with a small reduction in thickness

24、 tosmooth the surface and impart resistance to stretcher strainsand fluting. (Syn. skin passed sheet)DISCUSSIONExtra smooth is frequently specified when fluting orstretcher strains may be a hazard. Extra smooth may not be available inall coating types or weights (masses). (2006)fabricator, nas relat

25、ed to corrugated metal pipe,(1) theorganization that produces the finished pipe, or (2) forstructural plate pipe, the organization that processes flatsheets and other items needed for the field assembly of thefinished products. (1990)flakingSee delamination. (1994)galvanized coating, na coating of v

26、irtually pure zinc onsteel, applied by various methods or processes includinghot-dip process and electrodeposition (electrolytic process).DISCUSSIONFor hot-dipped galvanized coatings, the molten bath istypically at least 99 % zinc; as applied to the steel, the coating typicallycontains intermetallic

27、 layers of zinc-iron alloys adjacent to the steelsurface. Other methods of applying the zinc coating include metalspraying (metallizing), sherardizing, vacuum deposition, and mechani-cal deposition, but there is not general agreement that all produce a“galvanized coating”. There is general agreement

28、 that the coatingproduced by application of zinc-rich paint is not a “galvanizedcoating”. (1999)galvannealed coating, na coating on steel of zinc-basedalloy, containing about 6 to 15 % iron, produced by hot-dipimmersion in a high-zinc content coating bath, followed byheating the steel to induce diff

29、usion alloying between themolten zinc coating and the steel. (1994)heat, na specific lot of material representing a single melt ofsteel produced to a specified chemical analysis. (1991)heat analysis, nthe chemical composition of a specificproduction lot of liquid steel. (2003)DISCUSSIONThe sample on

30、 which the analysis is performed isusually taken from the molten steel.hot-dip process, nthe application of a metallic coating on asteel product by immersion of the product in the moltenmetal which forms the coating; the coating is applied ineither a continuous process or a batch process. (2006)DISC

31、USSIONMetallic coatings applied by the hot-dip process arecharacterized by the presence of an intermediate alloy layer whichforms as a result of a metallurgical reaction between the steel surfaceand the molten metal.inclusion control, nthe process of reducing the volumefraction of inclusions or modi

32、fying the shape of inclusions toimprove formability, weldability, and machinability.DISCUSSIONInclusions, especially those elongated during the rollingprocess, create the conditions for initiating, and/or propagating crackswhen the material is stretched or bent during the manufacture of a part.The a

33、dverse effects of inclusions are minimized by reducing the contentof inclusions in the steel and/or by altering the shape of inclusionsthrough the use of additions during the steelmaking process that changethe elongated shape of the inclusions to less harmful, small, well-dispersed globular inclusio

34、ns. (2008)lot, na finite quantity of a given product, produced underconditions that are considered uniform for sampling pur-poses.DISCUSSIONIn the case of metallic-coated iron or steel products, theconditions which may be considered necessary for a single lot aresimilar units, coating at approximate

35、ly the same time, in the samemanner, in a single coating bath. Consideration must also be given tothe uniformity of the iron or steel product to which the coating isapplied, such as being from a single heat. For material sampled aftershipment from the manufacturers or coaters facility (where the hea

36、t orprocessing identification may have been lost), a lot would consist of allsimilar material in a given shipment. (2006)manufacturer, nas related to corrugated metal pipe, theorganization that produces the metal sheet from which pipeis made. (1990)mechanical polishing, nof metallic coatings, the lo

37、oseningand detachment of superficial, small particles of coatingmetal during processing or testing, due to mechanicalabrasion. (1994)A 902 08a2minimum thickness, nof steel sheet, an ordering designa-tion which indicates that the applicable tolerance for thick-ness is all plus from the ordered thickn

38、ess.DISCUSSIONAs an example, the thickness tolerance for sheet mate-rial ordered as 0.035 in. minimum is +0.008 in., 0.000 in., and theallowable range of thickness is 0.035 in. to 0.043 in. or ordered as 1.32mm minimum is +0.26 mm, 0.00 mm, and the allowable range ofthickness is 1.32 mm to 1.58 mm.

39、The total thickness tolerance forsheet ordered to minimum thickness is usually twice the tabulartolerance for sheet ordered to nominal thickness. (1997)nominal thickness, nof steel sheet, an ordering designationwhich indicates that the applicable tolerance for thickness isboth plus and minus from th

40、e ordered thickness.DISCUSSIONAs an example, the thickness tolerance for sheet mate-rial ordered as 0.035 in. nominal is +0.004 in., 0.004 in., and theallowable range of thickness is 0.031 in. to 0.039 in. or ordered as 1.32mm nominal is +0.13 mm, 0.13 mm, and the allowable range ofthickness is 1.19

41、 mm to 1.45 mm. In some cases, the purchaser mayspecify the tolerances unequally, such as +0.006 in., 0.002 in. or+0.20 mm, 0.06 mm. The total tolerance is always the same, whetherindicated equally or unequally, plus and minus. (2003)oiled, adjdescribing a coating applied to metallic coatedsteel she

42、et alone or in addition to chemical treatment forfurther protection against the onset of storage corrosion; theoil coating is intended as a corrosion inhibitor only and notas a rolling or drawing lubricant. (2001)peelingSee delamination. (1994)phosphatized, adjpertains to chemical treatment, in a ph

43、os-phate solution, of uncoated and metallic coated sheet toprepare the surface for painting without further treatmentexcept normal cleaning. (Syn. phosphated, phosphatecoated)DISCUSSIONThis is a surface treatment only and other characteris-tics of the metallic coating remain unchanged on phosphatize

44、d sheet.Cleaning procedures are described in Guides D 6386 and D 7396.(1993)powdering, nas related to metallic coatings, microcrackingand fine particle separation of generally brittle coatings whenthe coating is severely stressed. (2005)product analysis, na chemical analysis of the semifinishedor fi

45、nished steel. (1993)purchaser, nas related to corrugated metal pipe, the personor agency that purchases the finished pipe. (1990)sample, na portion of the material in a lot, selected accord-ing to a specific sampling plan, intended to represent the lot.DISCUSSIONThe sample may consist of one or more

46、 discrete units,or may be one or more portions selected from one or more large units(such as from a coil of wire or steel sheet). (1994)seam, nin wire, a longitudinal discontinuity that extendsradially into the wire from its surface.DISCUSSIONThe discontinuity may appear as a crack. The discon-tinui

47、ty can develop during solidification, rolling, or the wire drawingoperation as a result of dynamic strain aging.Aseam originating in wiredrawing is also known as a split. (1992)skin passed sheet, nSynonym for extra smooth sheet.(1991)spallingSee delamination. (1997)spangle, nin hot-dip coatings, the

48、 crystalline structure thatdevelops on a metallic-coated surface when the moltencoating metal solidifies, especially on steel sheet and articlescoated after fabrication.DISCUSSIONThe crystalline structure can range from large, veryvisible dendritic grains to small, equiaxed grains that are difficult

49、 todiscern with the unaided eye. Variables that affect the crystal size andvisibility include: steel substrate composition and prior treatment,coating bath composition, coating solidification rate and post coatingprocessing such as temper rolling. (2005)specimen, na portion of a sample on which a specific test orevaluation is performed. (2005)stabilized steel, na steel which has been treated with one ormore carbide- or nitride-forming elements such as titanium,vanadium, or columbium, to control the level of interst