Metal Terminology (B)金属术语B

BAINITE
Aslender,needle-like(acicular)microstructureappearinginspringsteelstripcharacterizedbytoughnessandgreaterductilitythantemperedMartensite.BainiteisadecompositionproductofAustenitebestdevelopedatinterruptedholdingtemperaturesbelowthoseformingfinepearliteandabovethosegivingMartensite.

BANDEDSTRUCTURE
Appearanceofametal,underamicroscopeorviewedbythenakedeye,onfracturedorsmoothedsurfaces,withorwithoutetching,showingparallelbandsinthedirectionofrollingorworking.

BANDSAWSTEEL(WOOD)
Ahardenedtemperedbrightpolishedhighcarboncoldrolledspringsteelstripproducedespeciallyforuseinthemanufactureofbandsawsforsawingwood,nonferrousmetals,andplastics.UsuallycarriessomenickelandwithaRockwellvalueofapproximatelyC40/45.

BARK
Surfaceofmetal,undertheoxide-scalelayer,resultingfromheatinginanoxidizingenvironment.Inthecaseofsteel,suchbarkalwayssuffersfromdecarburization.

BASEBOX
(SeeTinPlateBaseBox)

BASICOPENHEARTH
(SeeOpenHearthProcess)

BASICOXYGENPROCESS
Asteelmakingprocesswhereinoxygenofthehighestpurityisblownontothesurfaceofabathofmoltenironcontainedinabasiclinedandladleshapedvessel.ThemeltingcycledurationisextremelyshortwithqualitycomparabletoOpenHearthSteel.

BASICPROCESS
AsteelmakingprocesseitherBessemer,openhearthorelectric,inwhichthefurnaceislinedwithabasicrefractory.Aslag,richinlime,beingformedandphosphorousremoved.

BASICSTEEL
(SeeBasicProcess)

BATHANNEALING
Immersioninaliquidbath(suchasmoltenleadorfusedsalts)heldatanassignedtemperature.Whenaleadbathisused,theprocessisknownasleadannealing.

BAUXITE
Theonlycommercialoreofaluminum,correspondingessentiallytotheformulaAl2O3xH2O.

BEADING
Raisingaridgeonsheetmetal.

BENDTEST
Varioustestsusedtodeterminethetoughnessandductilityofflatrolledmetalsheet,striporplate,inwhichthematerialisbentarounditsaxisoraroundanoutsideradius.Acompletetestmightspecifysuchabendtobebothwithandagainstthedirectionofgrain.Fortesting,samplesshouldbeedgefiledtoremoveburrsandanyedgewisecracksresultingfromslittingorshearing.Ifaviceistobeusedthenlinethejawswithsomesoftmetalorbrass,soastopermitafreeflowofthemetalinthesamplebeingtested.

BERYLLIUMCOPPER
Analloyofcopperand2-3%berylliumwithoptionallyfractionalpercentagesofnickelorcobalt.Alloysofthisseriesshowremarkableage-hardeningpropertiesandanultimatehardnessofabout400Brinell(RockwellC43).Becauseofsuchhardnessandgoodelectricalconductivity,beryllium-copperisusedinelectricalswitches,springs,etc.

BESSEMERPROCESS
Asteelmakingprocessinwhichairisblownthroughthemoltenironsothattheimpuritiesarethusremovedbyoxidation.

BILLET
(SeeBloom)

BINARYALLOY
Analloycontainingtwoelements,apartfromminorimpurities,asbrasscontainingthetwoelementscopperandzinc.

BLACKANNEALING
Aprocessofboxannealingorpotannealingferrousalloysheet,striporwireafterhotworkingandpickling.(SeeBoxAnnealing)

BLACKOILTEMPEREDSPRINGSTEELSTRIP
(ScalelessBlue.)Aflatcoldrolledusually.70/.80%mediumhighcarbonspringsteelstrip,blue-blackincolor,whichhasbeenquenchedinoilanddrawntodesiredhardness.WhileitlooksandactsmuchlikebluetemperedspringsteelandcarriesaRockwellhardnessofC44/47,ithasnotbeenpolishedandislowerincarboncontent.Usedforlessexactingrequirementsthanclockspringsteel,suchassnaps,locksprings,holddownsprings,trapsprings,etc.Itwilltakeamoreseverebendbeforefracturethanwillclockspring,butitdoesnothavethesamedegreeofspring-back.

BLACKPLATE
Alightweightorathinuncoatedsteelsheetorstripsocalledbecauseofitsdarkoxidecoloringpriortopickling.Itismanufacturedbytwodifferentprocesses.(1)Fromsheetbaronsinglestandsheetmillsorsheermillsintandem.Thismethodisnowalmostobsolete.(2)Onmodern,highspeedcontinuoustandemcoldreductionmillsfromcoiledhotrolledpickledwidestripintoribbonwoundcoilstofinishedgage.Sizesrangefrom12”to32”inwidth,andinthicknessesfrom55lbs.to275lbs.baseboxweight.Itisusedeitherasisforstampings,ormaybeenameledorpaintedortinorternecoated.

BLASTFURNACE
Averticalshafttypesmeltingfurnaceinwhichanairblastisused,usuallyhot,forproducingpigiron.Thefurnaceiscontinuousinoperationusingironore,coke,andlimestoneasrawmaterialswhicharechargedatthetopwhilethemoltenironandslagarecollectedatthebottomandaretappedoutatintervals.

BLASTBOX
(SeeTinPlateBaseBox)

BLISTER
Adefectinmetalproducedbygasbubbleseitheronthesurfaceorformedbeneaththesurfacewhilethemetalishotorplastic.Veryfineblistersarecalled“pin-head”or“pepper”blisters.

BLOOM
(Slab,Billet,Sheet-Bar.)Semifinishedproducts,hotrolledfromingots.Thechiefdifferencesareintheircrosssectionalareasinratioofwidthtothickness,andintheirintendeduse.

BLOOMING-MILL
Amillusedtoreduceingotstoblooms,billets,slabs,sheet-baretc.(SeeSemi-FinishedSteel)

BLOWHOLE
Acavityproducedduringthesolidificationofmetalbyevolvedgas,whichinfailingtoescapeisheldinpockets.

BLUEANNEALING
Aprocessofsofteningferrousalloysintheformofhotrolledsheet,byheatingintheopenfurnacetoatemperaturewithinthetransformationrangeandthencoolinginair.Theformationofbluishoxideonthesurfaceisincidental.

BLUEBRITTLENESS
Reducedductilityoccurringasaresultofstrainaging,whencertainferrousalloysareworkedbetween300?and700癋.Thisphenomenonmaybeobservedattheworkingtemperatureorsubsequentlyatlowertemperatures.

BLUETEMPEREDSPRINGSTEELSTRIPS
(SeeTemperedSpringSteelStrip)

BLUING
(1)Sheets-Amethodofcoatingsheetswithathin,evenfilmofbluish-blackoxide,obtainedbyexposuretoanatmosphereofdrysteamorair,atatemperatureofabout1000癋,generallythisisdoneduringbox-annealing.(2)Bluingoftemperedspringsteelstrip;anoxidefilmblueincolorproducedbylowtemperatureheating.

BODY-CENTERED
(Concerningspacelattices.)Havingtheequivalentlatticepointsatthecornersoftheunitcell,andatitscenter;sometimescalledcenteredorspace-centered.

BONDERIZING
Thecoatingofsteelwithafilmcomposedlargelyofzincphosphateinordertodevelopbetterbondingsurfaceforpaintorlacquer.

BORON
(ChemicalSymbolB)-ElementNo.5oftheperiodicsystem.Atomicweight10.82.Itisgrayincolor,ignitesatabout1112癋.andburnswithabrilliantgreenflame,butitsmeltingpointinanon-oxidizingatmosphereisabout4000癋.Boronisusedinsteelinminutequantitiesforonepurposeonly-toincreasethehardenabilityasincasehardeningandtoincreasestrengthandhardnesspenetration.

BOTTLETOPMOLD
Ingotmold,withthetopconstricted;usedinthemanufactureof“cappedsteel,”themetalintheconstrictionbeingcoveredwithacapfittedintothebottleneck,whichstops“rimming”actionbytrappingescapinggases.

BOW
(SeeCamber)

BOXANNEALING
Aprocessofannealingaferrousalloyinasuitableclosedmetalcontainer,withorwithoutpackingmaterials,inordertominimizeoxidation.Thechargeisusuallyheatedslowlytoatemperaturebelowthetransformationrange,butsometimesaboveorwithinit,andisthencooledslowly.Thisprocessisalsocalled“closeannealing”or“potannealing.”(SeeBlackAnnealing)

BRAKE
Apieceofequipmentusedforbendingsheet:alsocalleda“barfolder.”Ifoperatedmanually,itiscalleda“handbrake”;ifpowerdriven,itiscalleda“pressbrake.”

BRALE
Adiamondpenetrator,conicalinshape,usedwithaRockwellhardnesstesterforhardmetals.

BRASS(Cartridge)
Strip.70%copper30%zinc.Thisisoneofthemostwidelyusedofthecopper-zincalloys;itismalleableandductile;hasexcellentcold-working;poorhotworkingandpoormachiningproperties;developshightensilestrengthwithcold-working.TemperisimpairedbycoldrollingandclassifiedinhardnessbythenumberofB&SGagesofrolling(reductioninthickness)fromthepreviousannealinggage.Ratedexcellentforsoft-soldering;goodforsilveralloybrazingoroxyacetyleneweldingandfairforresistanceofcarbonarcwelding.Usedfordrawncartridges,tubes,eyeletmachineitems,snapfasteners,etc.

BRASSSHIM
(SeeSHIM)

BRASS(Yellow)
Strip.65%copperand35%zinc.Knownas“HighBrass”or“TwotoOneBrass.”Acopper-zincalloyyellowincolor.FormerlywidelyusedbutnowlargelysupplantedbyCartridgeBrass.

BRASSES
Copperbasealloysinwhichzincistheprincipaladdedelement.Brassisharderandstrongerthaneitherofitsalloyingelementscopperorzinc;itismalleableandductile;developshightensilewithcold-workingandnotheattreatableforpurposesofhardnessdevelopment.

BRAZING
Joiningmetalsbyfusionofnonferrousalloysthathavemeltingpointsabove800癋.butlowerthanthoseofthemetalsbeingjoined.Thismaybeaccomplishedbymeansofatorch(torchbrazing),inafurnace(furnacebrazing)orbydippinginamoltenfluxbath(diporfluxbrazing).Thefillermetalisordinarilyinrodformintorchbrazing;whereasinfurnaceanddipbrazingtheworkmaterialisfirstassembledandthefillermetalmaythenbeappliedaswire,washers,clips,bands,ormaybeintegrallybonded,asinbrazingsheet.

BREAKTEST
(Fortemperedsteel)Amethodoftestinghardenedandtemperedhighcarbonspringsteelstripwhereinthespecimenisheldandbentacrossthegraininavice-likecalibratedtestingmachine.Pressureisapplieduntilthemetalfracturesatwhichpointareadingistakenandcomparedwithastandardchartofbrakelimitationsforvariousthicknessrange.(SeeBendTest)

BRIDLING
Thecoldworkingofdeadsoftannealedstripmetalimmediatelypriortoaforming,bending,ordrawingoperation.AprocessdesignedtopreventtheformulationofLuder’slines.Caution:Bridledmetalshouldbeusedpromptlyandnotpermittedto(ofitself)returntoitspre-bridledcondition.

BRIGHTANNEALEDWIRE
Steelwirebrightdrawnandannealedincontrollednon-oxidizingatmospherefurnace.

BRIGHTANNEALING
Aprocessofannealingusuallycarriedoutinacontrolledfurnaceatmospheresothatsurfaceoxidationisreducedtoaminimumandthesurfaceremainsrelativelybright.

BRIGHTBASICWIRE
Brightsteelwire,slightlysofterthanBrightBessemerWire.Usedforroundheadwoodscrews,boltsandrivets,electricweldedchain,etc.

BRIGHTBESSEMERWIRE
Stiffbrightsteelwireofharddrawntemper.Normallydrawntosizewithoutannealing.Usedfornails,flatheadwoodscrews,cheapsprings,etc.

BRIGHTCOMMERCIALFINISH
(SeeFinishes)

BRIGHTDIP
Anacidsolutionintowhicharticlesaredippedtoobtainaclean,brightsurface.

BRINELLHARDNESS(Test)
Acommonstandardmethodofmeasuringthehardnessofcertainmetals.Thesmoothsurfaceofthemetalissubjectedtoindentationbyahardenedsteelballunderpressureorload.Thediameteroftheresultantindentation,inthemetalsurface,ismeasuredbyaspecialmicroscopeandtheBrinellhardnessvaluereadfromachartorcalculatedformula.

BRITTLENESS
Atendencytofracturewithoutappreciabledeformation.

BROACHING
Multipleshaving,accomplishedbypushingatoolwithsteppedcuttingedgesalongthework,particularlythroughholes.

BRONZE
Primarilyanalloyofcopperandtinbutthenameisnowappliedtootheralloysnotcontainingtin;e.g.,aluminum,bronze,manganesebronze,andberylliumbronze.Forvarietiesandusesoftinbronzesee(AlphaBronzeandPhosphorBronze).

BROWN&SHARPEGAGES(B&S)
Astandardseriesofsizesarbitrarilyindicated,asbynumbers,towhichthediameterofwireorthicknessofsheetmetalisusuallymadeandwhichisusedinthemanufactureofbrass,bronze,copper,copper-basealloysandaluminum.Thesegagenumbershaveadefiniterelationshiptoeachother.Bythissystemthedecimalthicknessisreducedby50%everysixgagenumbers-whiletemperisexpressedbythenumberofBSgagenumbersascoldreducedinthicknessfrompreviousannealing.ForeachB&Sgagenumberinthicknessreduction,thereisassignedahardnessvalueof?hard.Toillustrate:Onenumberhard=?hard,twonumbershard=?hard,etc.

BUCKLE
Alternatebulgesorhollowsrecurringalongthelengthoftheproductwiththeedgesremainingrelativelyflat.

BURNING
Heatingametalbeyondthetemperaturelimitsallowableforthedesiredheattreatment,orbeyondthepointwhereseriousoxidationorotherdetrimentalactionbegins.

BURNT
Atermappliedtoametalpermanentlydamagedbyoverheating.

BURR
Athinridgeorroughnessleftbyacuttingoperationsuchasinmetalslitting,shearing,blankingorsawing.ThisiscommontoaNo.3slitedgeinthecaseofsteel.

BUTCHERSAWSTEEL
Ahardened,tempered,andbrightpolishedhighcarbonspringsteelstrip(carboncontentabithigherthaninwoodbandsawquality)withaRockwellvalueofapproximatelyC47/49.

BUTTWELDING
Joiningtwoedgesorendsbyplacingoneagainsttheotherandweldingthem.