ColdRollingMasterclassShanghai,July2011RobHudsonCONFIDENTIALWhoamI?RobHudson,MetalsScientist–EuropeHonoursdegreeinAppliedChemistryandCharteredChemistWorkforI&DmetalworkinginMonchengladbachGermanyLiveinManchesterintheUKWorkedintechnicalMetalworkingrolessince1988

CONFIDENTIALAgendaColdRollingoverview

-Overviewofmarket

-Introductiontorollingandcoldmill

-Milltypes;problemsandbenefits

-Metallurgylimitations

-Forwardslip–definitionTraditionalapproachestocoldrollinglubrication

-FormulationconceptsSCRFproject

-Classicalevolutionofthetechnology

-ResearchworkCONFIDENTIALColdRolledSteel

CONFIDENTIALGlobalColdMillMarketMarketSectorNumberofMillsMarketValue

M$TotalMarketAnalysed746380CarbonSteel(>1mwide)351325StainlessSteel(>1mwide)16526Others23029TotalMarketValue~USD380millionSalesCONFIDENTIALColdRollingMarketSegments

CoolantandMillTypesCoolantTypeSpecifictoprocess:

CarbonSteel

Emulsionsforcostandhighproduction

StainlessSteelNeatOilforhighsurfacefinishproducts

ElectricalandSpecialSteels

Emulsionsorneatoil

CONFIDENTIALGlobalColdMarket

RegionalandCountrySplitMarketRevenuebyMajorCountriesCONFIDENTIALGlobalColdMarket

TechnicalDrive

Increaseinreductions

-higherdemandforlightergauge;AutoandHDG

-efficiencyofprocessdemands;picklelineandCAPL

-savingthenumberofpassesonreversingmill

-theneedforultrathinorultrahardmaterials

ImprovementsinStripCleanliness

-exitingstripiseithercleanedonrouteasstandaloneprocess(ECL)orincorporatedintocontinuousprocess(CAPL)

-Cheaperoptionis“millcleansheetroute”;wherematerialisonlyannealedbutrequiresgoodqualityrollinglubricantstoannealcleanCONFIDENTIALRollingTheoryLeonardoDeVinciproposedprinciples(1452-1519)ManglesandpastasheetrollersadoptthesamemechanicsCONFIDENTIALRollingTheory-1Rollingisaprogressivereductionatvaryingspeed,ofsheetsteelthickness,toextendlengthbyapplyingverticalforce(load)LoadLoadCONFIDENTIALRollingTheory-2Rollingisaprogressivereductionatvaryingspeed,ofsheetsteelthickness,toextendlengthbyapplyingverticalforce

load

andlongitudinalforce

(tension).tensiontensionLoadLoadCONFIDENTIALColdRollingTheoryEntrysideExitsideNeutralpoint–noslipmeansthestripandrollsarerunningatthesamespeedStripfasterthanrollsRollsfasterthanstripCONFIDENTIALToConsider…..MillType–ReversingorTandemWorkroll

-diameter

-thermalcrown/camber

-flattening

-forcevpressureAreasofrestrictedflowWorkhardeningandannealstressrelief(Slip)CONFIDENTIALChoiceofMill

ProcessandcommercialSinglestand

OperateinreversingsequencesMixedschedules,lowervolumeswithlongertimetorunindividualcoilsthroughthemillGenerallyslowerspeedstypically600–800m/minMuchmoreflexibleapplicationsOftenfirstopportunityforlubricantandmaterialtrials

Tandemmill

Offeraonce-throughcontinuousprocessStandardschedules,highvolumesExtremespeedsoftenwithaccumulatorsinfrontandbehindthemillsoasmillonly‘slowsdown’forweldLowestcostmodelforproduction,hencehighestriskfortrialworkCONFIDENTIALCarbonSteelColdRolling.4or6HighMillsStainlessSteelColdRolling.ColdRolling-MillConfigurationsReversingMillUpto350,000t.p.a.2StandReversingMillUpto800,000t.p.a.TandemMillUpto1,000,000t.p.a.ContinuousTandemMillUpto2,000,000t.p.a.12/20HighReversingMillUpto120,000t.p.a.4/6/ZHighReversingMillUpto150,000t.p.a.ProductionVolume:MillTypeCONFIDENTIAL4highConfigurationExitsideEntrySideReversingsinglestandmills,typical800m/min

Multistagemillssetupintandemwithfirststandfeedingthenext(typ4-6stands)Upto2000m/min

Variableentrygauges(3mmmax)downtovariableexitgauges;autosheet@0.7mm

Typicalreductionperstand/pass@25–40%

Typicalstriptempsonexitupto130°CCONFIDENTIAL4highTandemMillExitsideEntrySideCONFIDENTIAL6highConfigurationBackuprollsIntermediaterollsWorkrollsRollNo2carriestaperCONFIDENTIALSendzimirArrangement–20HighOutokomputrialworkCONFIDENTIALWorkRolls:ForcevPressureAThegreaterthereductionthelargerthecontactarea=largerarearequiresgreaterforcetomaintainunitpressureBThesmallertherollsthesmallerthecontactarea=unitpressuregreatestforsmallerworkrollsMaxreductions=smallworkrollsCONFIDENTIALColdRolling-MillStandTypes2High WRDia650–1050mm4High&6High WRDia400–600mmZHigh(or18High) WRDia100-180mmClusterorSendzimirMill WRDia50-150mm12High,20HighMKWMills WRDia200-350mmWorkRoll:SizeCONFIDENTIALWorkRolls-flatteningNoloadRolling–rollsflattenRollsdeflectedRollingCONFIDENTIALWorkRollsApairofrollsapplyingforcetometalarethemselvesbeingforcedapart–hence+vecamberrequiredtoallowforflatteningCONFIDENTIALWorkRolls-SummaryForexample:Smalldiameterworkroll

=smallerarcofcontact

=highunitpressure

=higherlevelsofdeformationperpass

=butmorepronetobeingdeformeditself

=requirescomplexsupportrollsystemtostopbending/flexing

=thermalcrownisdifficulttocontrol

=rollwearcanbehighCONFIDENTIALWorkRolls:ThermalCrownandCamberNotenoughcoolingandcrowngrowstooverreduceinthecentreToolittlecrownandtheedgesbecomeover-rolledCambermanagedin2ways–grindingorthermalcrownPleaseNote–coolantcontrolISshapecontrolCONFIDENTIALVitalFactorsforRollingPressuretodeformmetaldependson:

1–Hardnessandworkhardening2-Sizeoftheareasofrestrictedflow,whichrelatestotheareaofcontactbetweenstripandroll3–Thedistanceapartfortherestrictedflowzonestopandbottom–i.e..Howmuchfreemetalislefttoflow4–Theamountoflubricationintherollbite–thisremovestheinfluenceofrollroughnessPressurePressurefrictionRegionsofrestrictedflowCONFIDENTIALVitalFactorsforRollingLimitstorollingappearwhen:Asthematerialisrolledthinnerandthinnertheregionsofrestrictedflowaretooclosetogether

-thereislittlefreematerial,unrestrictedbyfriction,todeformAsaconsequencemoreloadisplacedontherolls

-whichinturnflattenstherollsincreasingsurfacecontactareaandmakingtheregionsofrestrictedflowlargerstill

-rollsflattensounitpressureisactuallyreducing

MaterialalsoworkhardensCONFIDENTIALVitalFactorsforRolling

AreasofrestrictedflowStand1Stand2Stand3Bystand3,highresistancetoflow,higherappliedforce,moreflattening–viscouscirclethatwillnotimprovedeformationCONFIDENTIALWorkHardening

Workhardening(strainhardening)isthestrengtheningofamaterialbyplasticdeformation

Strengtheningoccursduetodislocationmovementswithinthecrystallinestructureofthematerial

Themoreseverelyyoudeformthemoreyouharden;thisintroducestheneedforanneal;forstressrelief

Annealfollowedbyselectivere-hardening–throughtemperrolling/skinpass/DCRCONFIDENTIALDefinition:ForwardSlipRollspeed=stripspeedStripmovingfasterthanrolls–neutralpointpushedbackwardsintotheentrysideofthemill=forwardslipCONFIDENTIALSimplifiedColdRollingProcessRouteCONFIDENTIALTargetCarbonSheet

RecirculatingemulsionsCONFIDENTIALColdRolling–MillTypesZHighMill5StandCoupledTandemMillReversingMill3StandTandemMillinDRAPLine20HighMill4HighMillWhatdoesacoldMilllooklike?CONFIDENTIALColdMillLubrication

TheObjectivesFrictionmodification,coolingandfilmdepthtoseparatemetalandworkrolls,aswellasinter-rolllubrication

Levelofrequiredlubricityrequiredaremuchhigherthaninotherdeformationoperations

Thelevelofrequiredlubricityinrollingisdeterminedby:

-Materialrolled,stainless,highcarbon,lowcarbon,HSS,otherwhiteoryellowmetals

-Milltype;Tandem,Reversible,Sendzimir

-Workrollsize,workrollfinishandroughness

-Targetreductionsperstand(orperpass)CONFIDENTIALColdMillLubrication

TheObjectivesFilmstrength,toresistagainstcompressionintherollbite

Thermalstability,higherdemandsonthelubricantwillresultinhigherbiteandrolledstriptemperature;thermaldegradationofthefluidwillrenderitdifficulttoremoveincleaningoranneal

Chemicalstability,thefluidmustresistchemicaldegradation,forexamplehydrolysisandironsoapformation,againdirtystrip

wouldprevail

Plateout,isrequiredonworkrollsandstripsurfacetoprovideasufficientseparatingforceintherollbiteCONFIDENTIALColdMillLubrication

TheObjectivesPolarityoftheoil,thelowerthepolaritythelowertheoilplateoutwhichwillgivecleanersurfacebutlubricationwillbepoorhencelotsofironfines–balance

ParticleSize,iftoosmalltoolittleoilwilladheretostrip

WettingandDetergency,higherthedetergencythelessoilresidualonthesurfaceofthesteel;thisisgoodinthelaststandbutmaymeantoolittleoilinthereductionstands–underlubricationBALANCEISTHEKEY;CleanlinessandLubricationCONFIDENTIALColdMillLubricationOtherpropertiesofcoldmillcoolantinclude:

-needstoberelativelyconsistentandunchanginginuse

-rejectincomingrogueoils/demulsifying

-managemetallicfinestofilters

-offerdetergencyinuse

-offersomelevelofcorrosionresistancetomillhousingandcoil

-needstoannealclean–batchandcontinuous

-operatoracceptable

-offerextendedsumplife

-reducerollwear/lossofroughnesstorolls

-controlthermalstabilityofrollsthroughcoolingCONFIDENTIALTemperMillLubricationRollingThephysicalpropertiesareenhancedbythetemperpassthroughelongation;0.5%–7%max,andinclude:

DimensionaltruenessandrepeatabilitySuppressionofyieldpointelongationImprovedproductsurfacefinish,shapeandflatnessIncreaseproductyieldstrengthanddevelopstiffness

Rollfinishesrangefromgroundandpolishedrollstoimpartabrightfinish,toshot-blastedorelectric-dischargedtexturedrollsthatproduceadull,velvetyfinishonthesteelsurface.CONFIDENTIALStribeckCONFIDENTIALQuickFluidComparisonEmulsionRangeofTechnologyNeatOilsWetTemperContinuousPhaseWater>95%NeatoilWater>95%FilmformingcomponentMixedhighqualityestersCheapesterNone/tracepolymer–highlevelsofcorrosioninhibitorsPhosphorusSpecialistblends–wetting,FMandwearSimpleFMandwettingNoneSulphurSpecialistpacksforEPandannealNotcoreadditiveNoneSurfactantSpecialistandproprietaryNoneYesCONFIDENTIALGlossary

EstersSaponificationValueDefinesthecontent(butnottype)ofesterinthefluidEsteristhefilmformingcomponentPossesseshigherfilmformingcapabilitythanmineraloilSapvaluedefinesperformanceHighSapvaluedefinesshorterchainesters…..i.e.,CoconutC10/C12CONFIDENTIALEstersStructureAlcohol+Acid=Ester+WaterButylstearate=MonoesterTriglyceridePentaerythritolesterPolyester()()PolymeresterRapeseed;PalmCoconutCONFIDENTIALEsterAdsorptionOC=C=C=OOOOOCCCOC=C=C=OOOOOCCCOC=C=C=OOOOOCCCFeFe+Fe+Fe+Fe+Fe+Fe+Fe+Fe+Fe+Fe+Fe+CONFIDENTIALTypicalFattyacidDistribution

Saponifiablematter

CONFIDENTIALGlossary

IodineValue

Iodinevaluemeasurethedegreeofun-saturationonthefattychainItisexpressedas“mgIodineper100goffluid“ThehigherthenumberthedirtierthefattycomponentThelowerthenumberthecleanerthefluidthroughannealandthemoreconsistentitperformsthroughitslifetimeTheun-saturationmeasuredonthetestisintheformofdoublebondsalongthechain–sitesofhighelectrondensitythatwillbepronetoreaction

CoconutoilhasnearzeroIodinevalueandiscleaninannealRapeseedOilhas90–110IodinevalueandisnotcleanbutlubricatesbetterCONFIDENTIALGlossary

AcidvalueAcidvalueisameasureofthefreeaciditywithintheemulsionItisanimportantcriteriaforformulationasacidsprovide:

-boundaryperformance

-somecorrosionprotectionandfilm

-anironscavengingrole

-solubilisingroleforotheradditives

Acidvaluewillincludefattyacids(Oleine),butalsopartialphosphateswherethereisfreeacidityCONFIDENTIALGlossary

EPandAntiwearPerformancechemistrypackagesSulphurdesignedtoenhancefilmformingperformanceandpreventfilmbreakdown,addedbenefitofaidingannealbyreductionofcarbonPhosphorusaddedasfrictionmodifierandantiwearadditive,providingimprovedsurfacefinishestotherolledproduct,acidicnaturecanalsoactasscavengerforironCONFIDENTIALSulphurChemistrySulphurAdditivescanrangeasfollows:

PolysulphidesorSulphurisedunsaturatedprecursors(e.g.ester)Colour(yellowtoblack)Viscosity(40–~2000cst)SulphurContent(8–44%)Smell(mild–hardtocope/toostrong/pungent)CopperStaining(Note0-4)Solubilityinesters(mostlygood–butnotalways)Flashpoint(100->220°C)Price(mediumtoveryexpensive)SulfurAdditivesCONFIDENTIALSulphurisedesters

ModeofactionFe+Fe+Fe+Fe+Fe+Fe+Fe+Fe+Fe+Fe+Fe+Fe+SO=CRC=OOOCCCC=OSOSS-SRS2-4S2-4S2-4S2-4S2-4S2-4S2-4[]][(S0-3)SH(S0-3)CONFIDENTIAL

S-S-S-S-SCCS-S-S-S-SCCS-S-S-S-SCCFe+Fe+Fe+Fe+Fe+Fe+Fe+Fe+Fe+Fe+Fe+Fe+Polysulfide

AdsorptionCONFIDENTIALPhosphoricacid(ester)

acidic/neutral

Hardtoformulate–synergyandmultitaskingadditivesExpensivechemistryHighperformanceevenatmoderateconc.OptimumoftendifficulttofindinrollingPaletodarkcolourandlittletonosmellPotentialbreakdownproductduringusageProductLabellingWastedisposalcostsCONFIDENTIALPhosphoricacid(ester)R1–O–P–O–R2O=–OH-NH-RR1–O–P–O–R2O=–OR3

Phosphoricester,acidic/neutralPhosphoricester,neutralCONFIDENTIALSurfactantSystemsCationicDispersions

pHcontrolledcationiccharacterHigherlubricityforequivalentsapvalueShearinsensitivesystemwithhighparticlesizeOildropletsplateoutonceagitationceasesandtheemulsionfullysplitsVerytightpHbandforfullcationiccharactermakesthempronetoinfluencefromcontaminationorchangesinwaterqualityCONFIDENTIALSurfactantSystems

Non-ionic

2typesofsystem;withandwithoutpolymerPolymerfreetendtobelessstablesystemsusedwithinsmallermoreturbulentsystemsPolymeractsasstabilisersystemcoatingoildroplettoretainparticlesize–butpreventsfurtherrogueoilemulsif