ASTM NACE ASTMG193-2010 Standard Terminology and Acronyms Relating to Corrosion.pdf

1、Designation: NACE/ASTM G193 10Standard Terminology and Acronyms Relating toCorrosion1This standard is issued under the fixed designation; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of last revision. A number in parent

2、heses indicates the year of last reapproval.1. Scope1.1 This terminology and acronyms standard covers anddefines commonly used terms and acronyms in the field ofcorrosion. Related terms may be found in Terminologies D16,D4538, G40, or other ASTM terminology standards.1.2 This terminology and acronym

3、s standard is a result of anagreement between NACE International and ASTM Interna-tional Committee G01 on Corrosion of Metals and may notreflect the opinions of other ASTM committees.1.3 In this terminology and acronyms standard, brackets areused for directives that follow a definition and are obvio

4、uslynot part of it, such as, “see XXX” and “also known asXXX.” Brackets can also indicate the field of application orcontext of the definition or acronym.2. Referenced Documents2.1 ASTM Standards:2D16 Terminology for Paint, Related Coatings, Materials,and ApplicationsD4538 Terminology Relating to Pr

5、otective Coating andLining Work for Power Generation FacilitiesG40 Terminology Relating to Wear and Erosion2.2 NACE Standards:2NACE No. 1/SSPC-SP 5 White Metal Blast CleaningNACE No. 2/SSPC-SP10 Near-White Metal Blast CleaningNACE No. 3/SSPC-SP 6 Commercial Blast CleaningNACE No. 4/SSPC-SP 7 Brush-O

6、ff Blast Cleaning2.3 SSPC Surface Preparation Standards:3SSPC-SP 1 Solvent CleaningSSPC-SP 2 Hand Tool CleaningSSPC-SP 3 Power Tool CleaningSSPC-SP 8 Pickling3. Terminology3.1 Definitions:abrasivea solid substance that, owing to its hardness,toughness, size, shape, consistency, or other properties,

7、issuitable for grinding, cutting, roughening, polishing, orcleaning a surface by friction or high-velocity impact.abrasive blast cleaningcleaning and roughening of a sur-face produced by the high-velocity impact of an abrasive thatis propelled by the discharge of pressurized fluid from a blastnozzle

8、 or by a mechanical device such as a centrifugalblasting wheel. also referred to as abrasive blastingabrasive blastingsee abrasive blast cleaning.acceleratora chemical substance that increases the rate atwhich a chemical reaction (e.g., curing) would otherwiseoccur.AC impedancesee electrochemical im

9、pedance.acrylictype of resin polymerized from acrylic acid, meth-acrylic acid, esters of these acids, or acrylonitrile.activatora chemical substance that initiates a chemicalreaction (e.g., curing). Heat and radiation may also serve asactivators for some chemical reactions.active(1) a state of a met

10、al surface that is corroding withoutsignificant influence of reaction product; (2) the negativedirection of electrode potential.active-passive cellan electrochemical cell in which theanode is a metal in the active state and the cathode is thesame metal in the passive state.aeration cellsee different

11、ial aeration cell.air dryingprocess by which an applied wet coat converts toa dry coating film by evaporation of solvent or reaction withoxygen as a result of simple exposure to air withoutintentional addition of heat or a curing agent.airless sprayingprocess of spraying coating liquids usinghydraul

12、ic pressure, not air pressure, to atomize.alkydtype of resin formed by the reaction of polyhydricalcohols and polybasic acids, part of which is derived fromsaturated or unsaturated oils or fats.alligatoringpronounced wide cracking over the surface of acoating, which has the appearance of alligator h

13、ide.amphoteric metala metal that is susceptible to corrosion inboth acidic and alkaline environments.anaerobicabsence of air or free (molecular) oxygen.anchor patternsee surface profile.aniona negatively charged ion.1This terminology and acronyms standard is under the jurisdiction of NACE/ASTM Commi

14、ttee J01, Joint Committee on Corrosion, and is the direct responsi-bility of Subcommittee J01.02, Working Group on Terminology.Current edition approved Jan. 1, 2010. Published March 2010. Originallyapproved in 2009. Last previous edition approved in 2009 as G19309a. DOI:10.1520/G0193-10.2For referen

15、ced ASTM standards, visit the ASTM Web site, 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 Web site. For NACE standards, visit the NACE Web site, www.nace.org,or contact N

16、ACE FirstService at firstservicenace.org.3Available from The Society for Protective Coatings (SSPC), 40 24th St., 6thFloor, Pittsburgh, PA 15222-4656, http:/www.sspc.org.1 NACE International/ASTM International 2010 All rights reservedanodethe electrode of an electrochemical cell at whichoxidation oc

17、curs. (Electrons flow away from the anode in theexternal circuit. It is usually the electrode where corrosionoccurs and metal ions enter solution.)anode capan electrical insulating material placed over theend of the anode at the lead wire connection.anode corrosion efficiencythe ratio of the actual

18、corrosion(mass loss) of an anode to the theoretical corrosion (massloss) calculated from the quantity of electricity that haspassed between the anode and cathode using Faradays law.anodic inhibitora corrosion inhibitor whose primary actionis to reduce the rate of the anodic reaction, producing aposi

19、tive shift in corrosion potential.anodic polarization(1) the change of electrode potentialcaused by an anodic current flowing across the electrode/electrolyte interface; (2) a forced noble (positive) shift inelectrode potential. See polarization.anodic protectiona technique to reduce the corrosion r

20、ate ofa metal surface by polarizing that surface to a more oxidizingpotential.anodizingan electrochemical oxidation process that con-verts the surface of a metal (such as aluminum or titanium)to an oxide coating.anolytethe electrolyte adjacent to the anode of an electro-chemical cell.antifoulingprev

21、enting fouling. See fouling.attenuationelectrical losses in a conductor caused by cur-rent flow in the conductor.Auger electron spectroscopyanalytical technique in whichthe sample surface is irradiated with low-energy electronsand the energy spectrum of electrons emitted from thesurface is measured.

22、austenitethe face-centered cubic crystalline phase of iron oriron-based alloys.auxiliary electrodesee counter electrode.backfillmaterial placed in a hole to fill the space around theanodes, vent pipe, and buried components of a cathodicprotection system.barrier coating(1) a coating that has a high r

23、esistance topermeation of liquids and/or gases; (2) a coating that isapplied over a previously coated surface to prevent damageto the underlying coating during subsequent handling.beach marksthe characteristic markings on the fracturesurfaces produced by fatigue crack propagation. also knownas arres

24、t marks, clamshell marks, and conchoidal marksbeta curvea plot of dynamic (fluctuating) interferencecurrent or related proportional voltage (ordinate) versus thecorresponding structure-to-electrolyte potentials at a se-lected location on the affected structure (abscissa).binderthe nonvolatile portio

25、n of the vehicle of a formulatedcoating material.bituminous coatingan asphalt or coal-tar compound used toprovide a protective coating for a surface.blast angle(1) the angle of the blast nozzle with reference tothe surface during abrasive blast cleaning; (2) the angle ofthe abrasive particles propel

26、led from a centrifugal blastingwheel with reference to the surface being abrasive blastcleaned.bloomingsee blushing.blowdown(1) the injection of air or water under highpressure through a tube to the anode area for the purpose ofpurging the annular space and possibly correcting highresistance caused

27、by gas blockage cathodic protection use;(2) the process of discharging a significant portion of theaqueous solution in order to remove accumulated salts,deposits, and other impurities boiler or cooling water toweruse.blushingwhitening and loss of gloss of a coating, usuallyorganic, caused by moistur

28、e. also known as bloomingbracelet anodea galvanic anode with geometry suitable fordirect attachment around the circumference of a pipeline.This may be a half-shell bracelet consisting of two semicir-cular sections or a segmented bracelet consisting of a largenumber of individual sections.breakdown p

29、otentialthe least noble potential at whichpitting or crevice corrosion, or both, will initiate andpropagate in a specific environment.brittle fracturefracture with little or no plastic deformation.brush-off blast cleaned surfacean abrasive blast cleanedsteel surface that is free of all visible conta

30、minants andforeign matter but may have some tightly adherent millscale, rust, or coating. See NACE No. 4/SSPC-SP 7 fordetailed specification.calcareous coatinga layer consisting of calcium carbonateand other salts deposited on the surface. When the surface iscathodically polarized as in cathodic pro

31、tection, this layer isthe result of the increased pH adjacent to the protectedsurface.calcareous depositsee calcareous coating.case hardeninghardening a ferrous alloy so that the outerportion, or case, is made substantially harder than the innerportion, or core. Typical processes are carburizing, cy

32、anid-ing, carbonitriding, nitriding, induction hardening, and flamehardening.casein paintwater-thinned paint with vehicle derived frommilk.catalysta chemical substance, usually present in smallamounts relative to the reactants, that increases the rate atwhich a chemical reaction (e.g., curing) would

33、 otherwiseoccur, but is not consumed in the reaction.cathodethe electrode of an electrochemical cell at whichreduction is the principal reaction. (Electrons flow towardthe cathode in the external circuit.)cathodic corrosioncorrosion of a metal when it is a cathode,usually caused by the reaction of a

34、n amphoteric metal withthe alkaline products of electrolysis.NACE/ASTM NACE/ASTM G193 102 NACE International/ASTM International 2010 All rights reservedcathodic disbondmentthe destruction of adhesion betweena coating and the coated surface caused by products of acathodic reaction.cathodic inhibitora

35、 corrosion inhibitor whose primary ac-tion is to reduce the rate of the cathodic reaction, producinga negative shift in corrosion potential.cathodic polarization(1) the change of electrode potentialcaused by a cathodic current flowing across the electrode/electrolyte interface; (2) a forced active (

36、negative) shift inelectrode potential. See polarization.cathodic protectiona technique to reduce the corrosion rateof a metal surface by making that surface the cathode of anelectrochemical cell.catholytethe electrolyte adjacent to the cathode of anelectrochemical cell.cationa positively charged ion

37、.caustic crackingcracking of a metal or alloy under thecombined action of tensile stress and corrosion in thepresence of a strongly basic solution (e.g., sodium hydrox-ide, potassium hydroxide).caustic embrittlementan obsolete term referring to causticcracking.cavitationthe formation and rapid colla

38、pse of cavities orbubbles of vapor or gas within a liquid resulting frommechanical or hydrodynamic forces.cavitation-corrosionthe conjoint action of cavitation andcorrosion.cavitation damagethe degradation of a solid body resultingfrom its exposure to cavitation. (This may include loss ofmaterial, s

39、urface deformation, or changes in properties orappearance.)cavitation-erosionthe conjoint action of cavitation and ero-sion.cellsee electrochemical cell.cementationthe introduction of one or more elements intothe surface layer of a metal or alloy by diffusion at hightemperature. (Examples of cementa

40、tion include carburizingintroduction of carbon, nitriding introduction of nitrogen,and chromizing introduction of chromium.)chalkingthe development of loose, removable powder (pig-ment) at the surface of an organic coating, usually caused byweathering.checkingthe development of slight breaks in a co

41、ating thatdo not penetrate to the underlying surface.chemical conversion coatingan adherent, reaction-productlayer on a metal surface formed in situ by reaction with asuitable chemical, used for protective, decorative, or func-tional purposes. (It is often used to provide greater corrosionresistance

42、 or prepare the surface prior to the application of anorganic coating.)chevron patterna V-shaped pattern on a fatigue or brittle-fracture surface. The pattern can also be one of straightradial lines on cylindrical specimens.chloride stress corrosion crackingcracking of a metalunder the combined acti

43、on of tensile stress and corrosion inthe presence of an electrolyte containing dissolved chlorides.coatone layer of a coating system applied to a surface in asingle continuous application to form a uniform film whendry.coating(1) a liquid, liquefiable, or mastic composition that,after application to

44、 a surface, is converted into a solidprotective, decorative, or functional adherent film; (2) (in amore general sense) a thin layer of solid material on asurface that provides improved protective, decorative, orfunctional properties.coating systemthe complete number and types of coatsapplied to a su

45、bstrate in a predetermined order. (When usedin a broader sense, surface preparation, pretreatments, dryfilm thickness, and manner of application are included.)cold lapa linear discontinuity with rounded edges at exposedsurfaces that is caused by solidification of the meniscus of apartially cast meta

46、l or alloy (e.g., an anode used for cathodicprotection) as a result of interrupted flow of the castingstream or the joining of two casting streams at too low atemperature.cold shuthorizontal surface discontinuity caused by solidi-fication of a portion of a meniscus during the progressivefilling of a

47、 mold, which is later covered with more solidify-ing metal as the molten metal level rises. Cold shutsgenerally occur at corners remote from the point of mercial blast cleaned surfacean abrasive blast cleanedsteel surface that is free of all visible contaminants andforeign matter but may have some r

48、andom staining on nomore than 33 percent of the surface area. See NACE No.3/SSPC-SP 6 for detailed specification.concentration cellan electrochemical cell, the electromotiveforce of which is caused by a difference in concentration ofsome component in the electrolyte. (This difference leads tothe for

49、mation of discrete cathodic and anodic regions.)concentration polarizationthat portion of polarization of anelectrochemical cell produced by concentration changesresulting from current flowing through the electrolyte.conductive coating(1) a coating that conducts electricity;(2) an electrically conductive, mastic-like material used asan impressed current anode on reinforced concrete surfaces.conductive concretea highly conductive cement-based mix-ture containing