MECHANICALPROPERTIES - KOBELCO

1 Frequency [-] (Ann)Ti-9 (Ann)Ti-15Mo-5Zr-3Al(STA)Ti-15V-3Cr-3Sn- 3Al(STA)Ti-6Al-2Sn-4Zr-6Mo(STA)Ti-10V-2F e-3Al(STA) (ST)Commercially pure titanium (KS50)Commercially pure titanium (KS50) ELITi-15V-3Cr-3Sn-3Al (ST)Ti-6Al-4V ELI (ST) ELITi-6Al-4V ELI(ST) + + + + +07Ti-15V-3Cr-3Sn-3Al (STA)Ti-6Al-4V (Ann) , , ,toTi-15Mo-5Zr-3 AIwithatensilestrengthof1250 MPa.(TensilestrengthslistedaboveareKOBEL CO'sspecifiedminimumvalues.) C.( )High temperature characteristics Commerciallypuretitaniumisstableforusein thetemperaturerangeuptoapproximately300 Cduetoitsspecificstrength,creepresistanc e, ,titaniumalloysexhibithighstrengthinthet emperaturerangeuptoapproximately500 C.

2 ( )Low temperature characteristics , (-269 C).( )Fatigue characteristics Thefatiguestrength(107cycles)isroughlyeq uivalentto50%ofthetensilestrength,andwel dingdoesnotcauseasignificantdeclineinfat iguestrength.( )Inaddition,eveninseawater, Thefracturetoughnessoftitaniumalloysrang efrom28to108 , strength, strength (MPa)Tensile strength(MPa)Tensile strength(MPa) strength(MPa)Commercially pure titaniumCommercially pure titaniumTitanium alloyCommercially pure titaniumTitanium alloyTitanium :Tensile strength of commercially pure titaniums and various titaniumalloys, and yield strength(Specified minimum values) Tensile strengthSpecific strength [ yield strength/density] (kgf/mm2 /g/cm3)Aluminum alloyMagnesium alloySteel-nickel alloyTemperature ( C)Temperature ( C)Temperature ( C)Temperature ( C)Temperature ( C)Temperature ( C) :Specific strength of various materialsTable 1.

3 Representative characteristics of commercially pure titanium, titaniumalloys, and steel base materials (Plate materials) Mild steelStainless steel(SUS 304)MaterialTensiledirectionRepresentati ve (MPa)Tensilestrength(MPa)Elongation(%)El ongation(%)Elongation(%)Vickershardness( Hv)Erichsenvalue(mm) :Tensile characteristics of various commercially pure titaniums, various titaniumalloys and SUS304 under room temperature and high :Low temperature tensile properties of commercially pure titanium andvarious titanium alloysStress (MPa)Stress (MPa)Base materialWelded portion(400 C x 300min annealing)Heat-affected zone(400 C x 300min annealing)Repetition :Fatigue characteristics of commercially pure titanium (KS50) basematerial and welded portionPortionsBase materialBase materialWelded portionWelded portionBase materialBase materialStress ratio Notch.

4 Fatigue characteristics of Ti-6Al-4V base material and welded portion General corrosion11221211 Pittingcorrosion11242412 Crevicecorrosion11242423 Stress C82 C54 C32 + concentrationTantalumZirconiumHastelloy BTi-015Pd alloyTi-015Pd alloyT-15Mo-5Zr-3Al alloyTi-5Ta alloyAKOTC ommercially pure titaniumCommercially pure titaniumCommercially pure titaniumHastelloy CMonelMonelZirconiumHastelloy CInconel316 Stainless steel304 Stainless steel316 Stainless steel304 Stainless :Corrosion resistance range of various metals(Each metal shows excellent corrosion resistance in the arrow-marked range) (1) General properties Titaniumisnormallyanactivemetal, ( )Thepassivefilmoftitaniumprovidesextreme lyhighresistancetoseawaterbecause,unlike stainlesssteel,itisnoteasilybrokendownev enbychlorineions.

5 (2) Corrosion resistance against acid and alkaliPleasenotethathigh-concentrationno n-oxidizingacidssuchashydro , ,Ti-Ni-Pd-Ru-Cralloy (AKOT),etc. (Fig. 8)Titaniumexhibitexcellentcorrosionresis tanceagainstoxidizingacidssuchasnitricac id,chromicacid, ( )(3) Corrosion resistance against chloride solutionsUnlikestainlesssteelandcopperal loys,titaniumisnotsubjecttopittingcorros ionorstresscorrosioncracking,nortogenera lcorrosion.(Table2)However, , , AKOT,etc.( )(4) Stress corrosion crackingTitaniumissubjecttostresscorrosi oncrackingonlyincertainspecialenvironmen ts.

6 (Table3)Corrosion rate (mm/year)Corrosion rate (mm/year)Corrosion rate (mm/year)HCl (mass %)Boiling :Corrosion resistance of commercially pure titanium and corrosion resistanttitanium alloys in hydrochloric acid solutionNaOH (mass %) :Corrosion rate of commercially pure titanium deaerated NaOH solutionTemperature ( C)CI- concentration (mass %)Immune to crevice corrosionSusceptible to crevice corrosionPdO/TiO2 coated :Boundary of crevice corrosion of various titanium materials and stainless steel in chloride solutionTable 2:Comparison of corrosion resistance of various heat exchanger materialsTitaniumAl brass70/30 Cu-NiStainless steelCleanContaminatedCleanContaminatedC leanContaminatedCleanContaminatedCorrosi onresistancerankMaterialPurity ofsea waterCorrosion resistance rank.

7 1=Excellent 2=Good 3=Ordinary 4 =Inferior(5) Erosion resistanceTheerosionresistanceofcommerci allypuretitaniumisfarsuperiortothatofcop peralloys.( )(6) Galvanic corrosionIncomparisonwithotherpracticalm etals,theelectricpotentialoftitaniumishi gh.( )Therefore,iftitaniumcomesincontactwitho thermetalsoflowerpotentialsuchascopperal loysandaluminuminanelectricallyconductiv esolution,corrosionofsuchothermetalsmayb eaccelerated.(Galvaniccorrosion)Whenaust eniticstainlesssteelssuchasSUS304andSUS3 16comeincontactwithtitaniumunderroomtemp eratures,thereisgenerallynoproblemofgalv aniccorrosionduetothesmallerpotentialdif ferencesbetweenthesestainlesssteelsandti tanium.

8 (7) Reactivity to gasSincetitaniumhasastrongaffinityforoxy gen,hydrogen,andnitrogengases, ,butpleasenotethattitaniumreactssignific antlywithdrychlorinegas.(8) OtherGenerally,thecorrosionresistanceoft itaniumisnotaffectedbymaterialhistoryinc ludingwelding,finishing, :Natural potential of various metals in running seawaterVelocity: ~ : 10 ~ 27 CActivated conditionSource:LaQue, F. L.,"The behavior of nickel-copper alloys in seawater", Journal of the American society of naval engineers, vol. 53, February 1941, #1, , , , P38 Potential (V vs SCE)ZincBerylliumAluminum alloyMagnesiumCadmiumMild steel/Cast ironLow alloy steelAustenitic nickel cast ironAluminum bronzeNaval brass, bronze, red brassTinCopperSolder(50/50)Admiralty brass, aluminum brassManganese bronzeSilicon bronzeStainless steel(410,416)Stainless steel(316,317)Stainless steel(302,304,312,347)Stainless steel(430)

9 German silver90~10 Cupronickel80~20 Cupronickel70~30 CupronickelNickel, aluminum bronzeNickel -chrome alloy 600 (inconel 600)Silver soldersNickel 200 SilverNickel-copper alloy 400,K-50020 alloy (Carpenter 20)Nickel-iron-chrome alloy 825 (Inconel 825)TitaniumNi-Cr-Mo alloy C (Hastelloy C)Ni-Cr-Mo-Cu-Si alloy B (Hastelloy B)PlatinumGraphiteLeadTable 3:Environment causing titanium stress corrosion :Sand erosion resistance of commercially pure titanium and copperalloys in running sea waterLiquid metalEnvironmentNon-aqueous solutionAqueous solutionHigh temperature chlorideMethanol containing halogen or acidFuming red nitric asidBrineHigh temperature and high pressurebromide solutionMolten halogen saltHg.

10 CdCommercially pure titaniumTi-6Al-4 VHigh strength titanium alloySusceptible titanium materialsHigh strength titanium alloyHigh strength titanium alloyCommercially pure titaniumErosionNaval brassAluminum brass90/10 cupronickelAluminum bronzeCommercially pure titaniumSand content in seawater (g/l) Tin bronze(G&M)Non-oxidizingOxidizing23 C8m/s, sea water150hSand diameter < 50 mTi- 4:Corrosion resistance of titanium and other metals in various corrosive environmentsMACHININGC lassifi-cationConc.(mass%)Temperature( C)Corrosion mediumCorrosion resistanceCommercially puretitaniumUnalloyed zirconium304 stainless steelHastelloy CInorganicacidsHydrochloric acid (HCl)Sulfuric acid (H2SO4)Nitric acid (HNO3)OrganicacidsAcetic acid (CH3 COOH)Formic acid (HCOOH)Oxalic acid ((COOH) 2)Lactic acid (CH3CH (OH) COOH)AlkalisC