Metal Terminology (A)金属术语A

ACCORDIONREEDSTEEL
Hardened,tempered,polishedandbluedoryellowflatsteelwithdressededges.Carboncontentabout1.00%.Materialhastopossessgoodflatness,uniformhardnessandhighelasticity.

ACID-BRITTLENESS
Brittlenessresultingfrompicklingsteelinacid;hydrogen,formedbytheinteractionbetweenironandacid,ispartiallyabsorbedbythemetal,causingacidbrittleness.

ACID-PROCESS
Aprocessofmakingsteel,eitherBessemer,open-hearthorelectric,inwhichthefurnaceislinedwithasiliceousrefractoryandforwhichlowphosphorouspigironisrequiredasthiselementisnotremoved.

ACID-STEEL
Thetermhasnoreferencetotheacidityofthesteel.(SeeAcidProcess.)

AGEHARDENING
Thetermasappliedtosoftorlowcarbonsteels,relatestoslow,gradualchangesthattakeplaceinpropertiesofsteelsafterthefinaltreatment.Thesechanges,whichbringaboutaconditionofincreasedhardness,elasticlimit,andtensilestrengthwithaconsequentlossinductility,occurduringtheperiodinwhichthesteelisatnormaltemperatures.

AGING
Spontaneouschangeinthephysicalpropertiesofsomemetals,whichoccursonstanding,atatmospherictemperaturesafterfinalcoldworkingorafterafinalheattreatment.Frequentlysynonymouswiththeterm“Age-Hardening.”

AIRCOOLING
Coolingoftheheatedmetal,intermediateinrapiditybetweenslowfurnacecoolingandquenching,inwhichthemetalispermittedtostandintheopenair.

AIRHARDENINGSTEEL
Alloysteelwhichmaybehardenedbycoolinginairfromatemperatureabovethetransformationrange.Suchsteelsattaintheirmartensiticstructurewithoutgoingthroughthequenchingprocess.Additionsofchromium,nickel,molybdenumandmanganeseareeffectivetowardthisend.

AISISTEELS
SteelsoftheAmericanIronandSteelInstitute.CommonandalloysteelshavebeennumberedinasystemessentiallythesameastheSAE.TheAISIsystemismoreelaboratethantheSAEinthatallnumbersareprecededbyletters:“A”representsbasicopen-hearthalloysteel,“B”acidBessemercarbonsteel,“C”basicopen-hearthcarbonsteel,“CB”eitheracidBessemerorbasicopen-hearthcarbonsteel,“E”electricfurnacealloysteel.

ALCLAD
Thecommonnameforatypeofcladwroughtaluminumproducts,suchassheetandwire,withcoatingsofhigh-purityaluminumoranaluminumalloydifferentfromthecorealloyincomposition.Thecoatingsareanodictothecoresotheyprotectexposedareasonthecoreelectrolyticallyduringexposuretocorrosiveenvironments.

ALLOTROPY
(SeePolymorphism)

ALLOY
(Met.)Metalpreparedbyaddingothermetalsornon-metalstoabasicmetaltosecuredesirableproperties.

ALLOYSTEEL
Steelcontainingsubstantialquantitiesofelementsotherthancarbonandthecommonly-acceptedlimitedamountsofmanganese,sulfur,silicon,andphosphorous.Additionofsuchalloyingelementsisusuallyforthepurposeofincreasedhardness,strengthorchemicalresistance.Themetalsmostcommonlyusedforformingalloysteelsare:nickel,chromium,silicon,manganese,tungsten,molybdenumandvanadium.“LowAlloy”steelsareusuallyconsideredtobethosecontainingatotaloflessthan5%ofsuchaddedconstituents.

ALPHABRASS
Acopper-zincalloycontainingupto38%ofzinc.Usedmainlyforcoldworking.

ALPHABRONZE
Acopper-tinalloyconsistingofthealphasolidsolutionoftinincopper.Commercialformscontain4or5%oftin.Thisalloyisusedincoinage,springs,turbine,blades,etc.

ALPHAIRON
Thepolymorphicformofiron,stablebelow1670癋.hasabodycenteredcubiclattice,andismagneticupto1410?F.

ALUMINUM
(ChemicalsymbolAl)ElementNo.13oftheperiodicsystem;.Atomicweight26.97;silverywhitemetalofvalence3;meltingpoint1220癋.;boilingpointapproximately4118癋.;ductileandmalleable;stableagainstnormalatmosphericcorrosion,butattackedbybothacidsandalkalis.Aluminumisusedextensivelyinarticlesrequiringlightness,corrosionresistance,electricalconductivity,etc.Itsprincipalfunctionsasanalloyinsteelmakingare;(1)Deoxidizesefficiently(SeeAluminumKilledSteel)(2)Restrictsgraingrowth(byformingdispersedoxidesornitrides)(3)Alloyingelementinnitridingsteel.

ALUMINUMKILLEDSTEEL
Asteelwherealuminumhasbeenusedasadeoxidizingagent.(SeeKilledSteel.)

AMORPHOUS
Non-crystalline.

ANNEALING
Aheatingandcoolingoperationimplyingusuallyarelativelyslowcooling.Annealingisacomprehensiveterm.Theprocessofsuchaheattreatmentmaybe:toremovestresses;toinducesoftness;toalterductility;toughness;electricalmagnetic,orotherphysicalproperties;torefinethecrystallinestructure;toremovegases;toproduceadefinitemicro-structure.Inannealing,thetemperatureoftheoperationandtherateofcoolingdependuponthematerialbeingheattreatedandthepurposeofthetreatment.

ANODIZING(AluminumAnodicOxideCoating)
Aprocessofcoatingaluminumbyanodictreatmentresultinginathinfilmofaluminumoxideofextremehardness.Awidevarietyofdyecoloredcoatingsarepossiblebyimpregnationinprocess.

ARTIFICIALAGING
Anagingtreatmentaboveroomtemperature.(SeePrecipitationHeatTreatmentandcomparewithNaturalAging)

A.S.T.M.
AbbreviationforAmericanSocietyforTestingMaterial.Anorganizationforissuingstandardspecificationsonmaterials,includingmetalsandalloys.

AUSTEMPERING
Atradenameforapatentedheattreatingprocessthatconsistsofquenchingaferrousalloyfromtemperatureabovethetransformationranges,inamediumhavingarateofheatabstractionsufficientlyhightopreventtheformationofhigh-temperaturetransformationproductsandinmaintainingthealloy,untiltransformationiscomplete,atatemperaturebelowthatofpearliteformationsandabovethatofmartensiteformation.

AUSTENITE
Phaseincertainsteels,characterizedasasolidsolution,usuallyoffcarbonorironcarbide,inthegammaformofiron.Suchsteelsareknownas“austenitic”.Austeniteisstableonlyabove1333癋.inaplaincarbonsteel,butthepresenceofcertainalloyingelements,suchasnickelandmanganese,stabilizestheausteniticform,evenatnormaltemperatures.

AUSTENITICSTEEL
Steelwhich,becauseofthepresenceofalloyingelements,suchasmanganese,nickel,chromium,etc.,showsstabilityofAusteniteatnormaltemperatures.