1、Designation: A902 12Standard TerminologyRelating to Metallic Coated Steel Products1This standard is issued under the fixed designation A902; 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 par
2、entheses 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 app
3、lied. 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 te
4、rm.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 B374) or with the abbreviation of the name of theorganization.1.4 A definition is a single sentence with addit
5、ional 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:2A641/A641M Specif
6、ication for ZincCoated (Galvanized)Carbon Steel WireA924/A924M Specification for General Requirements forSteel Sheet, Metallic-Coated by the Hot-Dip ProcessB374 Terminology Relating to ElectroplatingD6386 Practice for Preparation of Zinc (Hot-Dip Galva-nized) Coated Iron and Steel Product and Hardwa
7、reSurfaces for PaintingD7396 Guide for Preparation of New, Continuous Zinc-Coated (Galvanized) 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 ho
8、t-dip process. (2005)barb, nas related to barbed wire, a short length of wire, withexposed ends 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 a
9、nd locked intoplace at specified intervals. (1995)base metal, nas related to metallic-coated steel, 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 artic
10、lesthrough the various steps of the coating process, such as,cleaning, pickling, fluxing, and coating. (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 maxim
11、umforce may be developed after fracture of one or more individual wires.(1993)carbon steel, nsteel 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, tungst
12、en,vanadium, zirconium, or any other element added to obtaina desired alloying effect; (2) the 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 %, s
13、ilicon 0.60 %, columbium (niobium)0.015 %, vanadium 0.008 %, boron 0.0008 %, or titanium0.025 %; 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 quantiti
14、es ofcertain residual elements from the feed materials. When the quantity ofsuch retained elements exceeds the values listed in (4) above, thecharacteristics of the steel may differ from that of carbon steel without1This terminology is under the jurisdiction of ASTM Committee A05 onMetallic-Coated I
15、ron and Steel Products and is the direct responsibility ofSubcommittee A05.18 on Editorial and Terminology.Current edition approved May 1, 2012. Published June 2012. Originallyapproved in 1990. Last previous edition approved in 2009 as A902 - 09. DOI:10.1520/A0902-12.2For referenced ASTM standards,
16、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 section appears at the end of this standard.Copyright ASTM Internation
17、al, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.those 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)chemical treatment, na passivating s
18、urface protectant nor-mally applied to metallic coatings to retard the formation ofcorrosion products during shipment and storage (storagestain).DISCUSSIONThe corrosion-inhibiting characteristics of chemicaltreatments are limited. If chemically-treated material becomes wet inshipment or storage, the
19、 product should be used or dried immediately.Some types of chemical treatments may be inappropriate in certainapplications because of possible undesirable effects on further process-ing, such as phosphatizing, spot welding, or painting. (2007)continuous coating, nof metallic coated steel products, t
20、heprocess of uninterrupted passage of long lengths of steelproducts, usually steel sheet, tube, pipe, or wire, through thevarious processing steps such as cleaning, annealing, andcoating.DISCUSSIONContinuous coating involves the use of equipment thatis capable of joining long lengths of product with
21、out stoppage of thecoating process. Continuous coating of preformed tube or pipe islimited to the outer surface, since 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)
22、fromunderlying layers; the separation can occur in small localizedareas or large areas of surface.DISCUSSIONFlaking, peeling, and spalling are colloquial termssometimes used to describe the separation. (1997)differentially coated sheet, nmetallic coated sheet withunequal specifications for the weigh
23、t (mass) of metalliccoating on each of the two surfaces. (2012)electrolytic process, nthe application of a metallic coatingon 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 batchproces
24、s. (1995)extra smooth sheet, nproduct produced by cold rolling themetallic coated sheet with a small reduction in thickness toimpart both the desired surface texture and resistance tostretcher strains and fluting. (Syn. skin passed sheet)DISCUSSIONExtra smooth is frequently specified when fluting or
25、stretcher strains may be a hazard. Extra smooth may not be available inall coating types or weights (masses). (2012)fabricator, nas related to corrugated metal pipe,(1) theorganization that produces the finished pipe, or (2) forstructural plate pipe, the organization that processes flatsheets and ot
26、her items needed for the field assembly of thefinished products. (1990)flakingSee delamination. (1994)galvanized coating, na coating of virtually pure zinc onsteel, applied by various methods or processes includinghot-dip processes and electrodeposition (electrolytic pro-cesses).DISCUSSIONFor hot-di
27、pped galvanized coatings, the molten bath istypically at least 99 % zinc; as applied to the steel, the coating typicallycontains intermetallic layers of zinc-iron alloys adjacent to the steelsurface. Other methods of applying the zinc coating include metalspraying (metallizing), sherardizing, vacuum
28、 deposition, and mechani-cal deposition, but there is not general agreement that all produce a“galvanized coating.” There is general agreement that the coatingproduced by application of zinc-rich paint is not a “galvanizedcoating.” (1999)galvannealed coating, na coating on steel of zinc-basedalloy,
29、containing about 6 to 15 % iron, produced by hot-dipimmersion in a high-zinc content coating bath, followed byheating the steel to induce diffusion alloying between themolten zinc coating and the steel. (1994)heat, na specific lot of material representing a single melt ofsteel produced to a specifie
30、d chemical analysis. (1991)heat analysis, nthe chemical composition of a specificproduction lot of liquid steel. (2003)DISCUSSIONThe sample on 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
31、of the product in the moltenmetal which forms the coating; the coating is applied ineither a continuous process or a batch process. (2006)DISCUSSIONMetallic coatings applied by the hot-dip process arecharacterized by the presence of an intermediate alloy layer whichforms as a result of a metallurgic
32、al reaction between the steel surfaceand the molten metal.inclusion control, nthe process of reducing the volumefraction of inclusions or modifying the shape of inclusions toimprove formability, weldability, and machinability.DISCUSSIONInclusions, especially those elongated during the rollingprocess
33、, create the conditions for initiating, and/or propagating crackswhen the material is stretched or bent during the manufacture of a part.The adverse effects of inclusions are minimized by reducing the contentof inclusions in the steel and/or by altering the shape of inclusionsthrough the use of addi
34、tions during the steelmaking process that changethe elongated shape of the inclusions to less harmful, small, well-dispersed globular inclusions. (2008)lot, na finite quantity of a given product, produced underconditions that are considered uniform for sampling pur-poses.DISCUSSIONIn the case of met
35、allic-coated iron or steel products, theconditions which may be considered necessary for a single lot aresimilar units, coating at approximately 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 coa
36、ting isapplied, such as being from a single heat. For material sampled aftershipment from the manufacturers or coaters facility (where the heat orprocessing identification may have been lost), a lot would consist of allsimilar material in a given shipment. (2006)manufacturer, nas related to corrugat
37、ed metal pipe, theorganization that produces the metal sheet from which pipeis made. (1990)mechanical polishing, nof metallic coatings, the looseningand detachment of superficial, small particles of coatingmetal during processing or testing, due to mechanicalabrasion. (1994)A902 122minimum thickness
38、, nof steel sheet, an ordering designa-tion which indicates that the applicable tolerance for thick-ness is all plus from the ordered thickness.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 thickn
39、ess 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. The total thickness tolerance forsheet ordered to minimum thickness is usually twice the tabulartolerance for sheet ordered to nominal thickness. (1997)nominal
40、thickness, nof steel sheet, an ordering designationwhich indicates that the applicable tolerance for thickness isboth plus and minus from the 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
41、 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 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 alwa
42、ys the same, whetherindicated equally or unequally, plus and minus. (2003)oiled, adjdescribing a coating applied to metallic coatedsteel sheet alone or in addition to chemical treatment forfurther protection against the onset of storage corrosion; theoil coating is intended as a corrosion inhibitor
43、only and notas a rolling or drawing lubricant. (2001)peelingSee delamination. (1994)phosphatized, adjpertains to the treatment, in a phosphatesolution, of uncoated and metallic coated sheet to prepare thesurface for painting without further treatment except normalcleaning. (Syn. phosphated, phosphat
44、e coated)DISCUSSIONThis is a surface treatment only and other characteris-tics of the metallic coating remain unchanged on phosphatized sheet.Additional information about this and other types of available surfacetreatments is presented in Appendix X2 of Specification A924/A924M.Cleaning procedures a
45、re described in Guides D6386 and D7396. (2009)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 finished steel. (1993)purchaser,
46、 nas related to corrugated metal pipe, the entitythat contracts to buy the finished pipe. (2009)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 discrete units,or may be one or
47、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-tinuity can develop during solidificat
48、ion, 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 crystalline structure thatdevelo
49、ps 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 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)s
