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ASTM A240 304 316 Stainless hlau nruab nrab tuab phaj tuaj yeem txiav thiab Customized Tuam Tshoj Hoobkas Nqe

Khoom siv: 201/304/304l/316/316l/321/309s/310s/410/420/430/904l/2205/2507
Hom: Ferritic, Austenite, Martensite, Duplex
Technology: Cold Rolled thiab Kub Rolled
Cov ntawv pov thawj: ISO9001, CE, SGS txhua xyoo
Kev Pabcuam: Kev kuaj thib peb
Tus me nyuam: tsis pub dhau 10-15 hnub los yog xav txog qhov ntau

Stainless hlau yog cov hlau alloy uas muaj qhov tsawg kawg nkaus Chromium cov ntsiab lus ntawm 10.5 feem pua.Cov ntsiab lus Chromium ua rau nyias chromium oxide zaj duab xis ntawm cov hlau nto hu ua passivation txheej.Cov txheej no tiv thaiv corrosion los ntawm qhov tshwm sim ntawm cov hlau nto;Qhov ntau dua ntawm Chromium hauv cov hlau, qhov ntau dua qhov corrosion kuj.

Cov hlau tseem muaj ntau qhov sib txawv ntawm lwm cov khoom xws li Carbon, Silicon thiab Manganese.Lwm cov ntsiab lus tuaj yeem muab ntxiv kom muaj zog tiv thaiv corrosion (Nickel) thiab formability (Molybdenum).

Kev coj tus cwj pwm ntawm siab carbon martensitic stainless hlau (HCMSS) muaj kwv yees li 22.5 vol.% carbides nrog cov ntsiab lus siab ntawm chromium (Cr) thiab vanadium (V), tau kho los ntawm electron beam melting (EBM).Lub microstructure yog tsim los ntawm martensite thiab residual austenite theem, submicron siab V thiab micron siab Cr carbides yog tusyees faib, thiab cov hardness kuj siab.CoF txo qis los ntawm kwv yees li 14.1% nrog nce lub xeev khov kho vim kev hloov khoom siv los ntawm kev hnav mus rau lub cev tawm tsam.Muab piv rau cov cuab yeej martensitic steels kho tib txoj kev, hnav tus nqi ntawm HCMSS yuav luag tib yam ntawm cov khoom siv qis.Qhov tseem ceeb hnav mechanism yog kev tshem tawm ntawm cov hlau matrix los ntawm kev puas tsuaj ua raws li oxidation ntawm kev hnav, thaum peb cov khoom siv abrasive tshwm sim nrog nce load.Cov cheeb tsam ntawm cov yas deformation nyob rau hauv qhov hnav caws pliav txheeb xyuas los ntawm kev sib tw hardness mapping.Cov xwm txheej tshwj xeeb uas tshwm sim raws li kev hnav khaub ncaws nce ntxiv tau piav qhia tias yog carbide tawg, siab vanadium carbide tearout, thiab tuag tawg.Qhov kev tshawb fawb no ua rau pom kev coj tus yam ntxwv ntawm HCMSS additive manufacturing, uas tuaj yeem ua txoj hauv kev rau kev tsim cov khoom EBM rau hnav daim ntaub ntawv xws li shafts mus rau yas txhaj pwm.
Stainless hlau (SS) yog ib tug ntau yam tsev neeg ntawm steels lug siv nyob rau hauv aerospace, tsheb, khoom noj khoom haus thiab ntau lwm yam kev siv vim lawv siab corrosion kuj thiab haum mechanical zog1,2,3.Lawv lub siab corrosion kuj yog vim muaj cov ntsiab lus siab ntawm chromium (ntau tshaj 11.5 wt. %) hauv HC, uas pab tsim cov oxide zaj duab xis nrog cov ntsiab lus chromium siab nyob rau saum npoo 1.Txawm li cas los xij, cov qib stainless hlau feem ntau muaj cov ntsiab lus tsis tshua muaj carbon thiab yog li ntawd muaj kev txwv hardness thiab hnav tsis kam, ua rau txo qis kev pab cuam lub neej hauv cov khoom siv xws li aerospace landing components4.Feem ntau lawv muaj qhov hardness tsawg (nyob rau hauv thaj tsam ntawm 180 txog 450 HV), tsuas yog qee qhov kev kho cua sov martensitic stainless hlau muaj hardness siab (txog 700 HV) thiab cov ntsiab lus carbon siab (txog 1.2 wt%), uas tuaj yeem ua rau cov tsim ntawm martensite.1. Nyob rau hauv luv luv, ib tug high carbon cov ntsiab lus txo cov martensitic transformation kub, tso cai rau tsim ib tug tag nrho martensitic microstructure thiab nrhiav tau ib tug hnav-resistant microstructure ntawm siab txias nqi.Cov theem nyuaj (piv txwv li, carbides) tuaj yeem ntxiv rau cov hlau matrix los txhim kho qhov hnav tsis kam ntawm qhov tuag.
Kev taw qhia txog kev tsim khoom ntxiv (AM) tuaj yeem tsim cov khoom tshiab nrog cov khoom xav tau, cov yam ntxwv microstructural, thiab cov khoom siv zoo tshaj plaws5,6.Piv txwv li, hmoov txaj melting (PBF), yog ib qho ntawm cov khoom lag luam ntxiv cov txheej txheem welding feem ntau, koom nrog cov txheej txheem ua ntej-alloyed los ua cov khoom zoo sib xws los ntawm melting cov hmoov siv cov khoom siv cua sov xws li lasers lossis electron beams7.Ntau qhov kev tshawb fawb tau pom tias cov khoom siv hlau tsis muaj hlau txuas ntxiv tuaj yeem ua tau zoo dua qub ua qhov chaw.Piv txwv li, austenitic stainless steels raug rau cov khoom siv ntxiv tau pom tias muaj cov khoom siv zoo tshaj plaws vim lawv cov microstructure zoo dua (ie, Hall-Petch kev sib raug zoo) 3,8,9.Kev kho cua sov ntawm AM-kho ferritic stainless hlau tsim cov precipitates ntxiv uas muab cov khoom siv kho tshuab zoo ib yam li lawv cov khoom sib piv 3,10.Txais ob-theem stainless hlau nrog lub zog siab thiab hardness, ua tiav los ntawm kev ua ntxiv, qhov kev txhim kho cov khoom siv yog vim chromium-nplua nuj intermetallic theem hauv microstructure11.Tsis tas li ntawd, kev txhim kho cov khoom siv ntawm additive hardened martensitic thiab PH stainless hlau tuaj yeem tau txais los ntawm kev tswj cov austenite hauv microstructure thiab optimizing machining thiab kev kho cua sov tsis 3,12,13,14.
Txog rau tam sim no, cov khoom tribological ntawm AM austenitic stainless hlau tau txais kev saib xyuas ntau dua li lwm cov hlau stainless.Tus cwj pwm tribological ntawm laser melting nyob rau hauv ib txheej ntawm hmoov (L-PBF) kho nrog 316L tau kawm raws li kev ua haujlwm ntawm AM ua tsis tau.Nws tau raug pom tias txo qhov porosity los ntawm kev txo qhov nrawm nrawm lossis nce lub zog laser tuaj yeem txhim kho hnav tsis kam15,16.Li et al.17 tau soj ntsuam cov zawv zawg qhuav hnav nyob rau hauv ntau yam tsis muaj (load, zaus thiab kub) thiab pom tias chav tsev kub hnav yog lub ntsiab hnav mechanism, thaum nce zawv zawg ceev thiab kub txhawb oxidation.Cov txheej txheem oxide ua kom muaj kev ua haujlwm ntawm cov kabmob, kev sib txhuam txo qis nrog qhov kub thiab txias, thiab hnav tus nqi nce siab dua.Hauv lwm txoj kev tshawb fawb, ntxiv rau ntawm TICK18, TIC219, thiab Sic20 hais kom ua haujlwm hnyav ua haujlwm 316L Matrix sib txhuam cov khoom sib txhuam tawv tawv nrog cov ntim ntawm cov khoom sib xyaw.Ib txheej tiv thaiv oxide kuj tau pom nyob rau hauv L-PBF12 kho PH steel thiab SS11 duplex steel, qhia tias kev txwv tsis pub muaj austenite los ntawm kev kho cua sov tom qab 12 tuaj yeem txhim kho hnav tsis kam.Raws li cov ntsiab lus ntawm no, cov ntaub ntawv feem ntau yog tsom rau kev ua haujlwm tribological ntawm 316L SS series, thaum muaj cov ntaub ntawv me me ntawm kev ua haujlwm tribological ntawm series ntawm martensitic additively manufactured stainless steels nrog ntau dua cov ntsiab lus carbon.
Electron Beam Melting (EBM) yog cov txheej txheem zoo ib yam li L-PBF muaj peev xwm tsim cov microstructures nrog refractory carbides xws li siab vanadium thiab chromium carbides vim nws muaj peev xwm ncav cuag qhov kub thiab txias thiab scan nqi 21, 22. Cov ntaub ntawv uas twb muaj lawm ntawm EBM ua ntawm stainless steel yog tsuas yog tsom rau kev txiav txim siab qhov zoo tshaj plaws ELM ua tsis tau kom tau ib qho microstructure tsis muaj kab nrib pleb thiab pores thiab txhim kho cov khoom siv kho tshuab 23, 24, 25, 26, thaum ua haujlwm ntawm tribological khoom ntawm EBM kho stainless hlau.Txog tam sim no, cov txheej txheem hnav ntawm high-carbon martensitic stainless hlau kho nrog ELR tau kawm nyob rau hauv cov xwm txheej tsis tshua muaj, thiab cov yas deformation hnyav tau raug tshaj tawm tias tshwm sim nyob rau hauv abrasive (sandpaper test), qhuav, thiab av nkos-erosion tej yam kev mob27.
Txoj kev tshawb no tshawb xyuas qhov hnav tsis kam thiab kev sib txhuam ntawm cov pa roj carbon ntau martensitic stainless hlau kho nrog ELR nyob rau hauv cov zawv zawg qhuav tau piav qhia hauv qab no.Ua ntej, microstructural nta tau tus cwj pwm siv scanning electron microscopy (SEM), lub zog dispersive X-ray spectroscopy (EDX), X-ray diffraction thiab duab tsom xam.Cov ntaub ntawv tau txais nrog cov txheej txheem no yog siv los ua lub hauv paus rau kev soj ntsuam ntawm tribological tus cwj pwm los ntawm cov kev ntsuam xyuas qhuav reciprocating nyob rau hauv ntau yam loads, thiab thaum kawg lub hnav nto morphology raug tshuaj xyuas siv SEM-EDX thiab laser profilometers.Tus nqi hnav tau suav thiab muab piv nrog cov khoom siv martensitic zoo sib xws.Qhov no tau ua tiav txhawm rau tsim lub hauv paus rau kev sib piv cov txheej txheem SS no nrog kev siv ntau dua hnav nrog tib hom kev kho mob.Thaum kawg, daim ntawv qhia hla ntu ntawm txoj kev hnav yog qhia siv lub hardness mapping algorithm uas qhia txog cov yas deformation uas tshwm sim thaum sib cuag.Nws yuav tsum raug sau tseg tias cov kev ntsuam xyuas tribological rau txoj kev tshawb no tau ua kom nkag siab zoo dua cov khoom tribological ntawm cov khoom tshiab no, thiab tsis yog simulate ib daim ntawv thov tshwj xeeb.Txoj kev tshawb no ua rau muaj kev nkag siab zoo dua ntawm tribological cov khoom ntawm ib qho tshiab additively tsim martensitic stainless hlau rau hnav daim ntaub ntawv uas yuav tsum tau ua hauj lwm nyob rau hauv hnyav ib puag ncig.
Cov qauv ntawm high carbon martensitic stainless hlau (HCMSS) kho nrog ELR raws li lub npe Vibenite® 350 tau tsim thiab muab los ntawm VBN Components AB, Sweden.Cov tshuaj nominal muaj pes tsawg leeg ntawm tus qauv: 1.9 C, 20.0 Cr, 1.0 Mo, 4.0 V, 73.1 Fe (wt.%).Ua ntej, cov khoom siv zawv zawg qhuav (40 hli × 20 hli × 5 hli) tau tsim los ntawm cov khoom siv duab plaub (42 hli × 22 hli × 7 hli) yam tsis muaj kev kho tom qab cua sov siv hluav taws xob tawm tshuab (EDM).Tom qab ntawd cov qauv tau ua tiav hauv av nrog SiC sandpaper nrog cov nplej loj ntawm 240 txog 2400 R kom tau qhov roughness (Ra) txog li 0.15 μm.Tsis tas li ntawd, cov qauv ntawm EBM-kho siab-carbon martensitic cuab yeej steel (HCMTS) nrog cov tshuaj nominal muaj pes tsawg leeg ntawm 1.5 C, 4.0 Cr, 2.5 Mo, 2.5 W, 4.0 V, 85.5 Fe (wt. %) (ua lag luam hu ua Vibenite® 150) Kuj tau npaj ib yam nkaus.HCMTS muaj 8% carbides los ntawm ntim thiab tsuas yog siv los sib piv HCMSS cov ntaub ntawv hnav tus nqi.
Microstructural characterization ntawm HCMSS tau ua tiav siv SEM (FEI Quanta 250, USA) nruab nrog lub zog tawg X-ray (EDX) XMax80 ntes los ntawm Oxford Instruments.Peb random photomicrographs uas muaj 3500 µm2 tau coj mus rau hauv backscattered electron (BSE) hom thiab tom qab ntawd soj ntsuam siv cov duab tsom xam (ImageJ®)28 los txiav txim qhov feem ntawm thaj tsam (xws li ntim feem), qhov loj thiab cov duab.Raws li pom cov yam ntxwv morphology, thaj tsam feem raug muab sib npaug rau qhov ntim feem.Tsis tas li ntawd, qhov zoo ntawm carbides yog xam los ntawm kev sib npaug ntawm qhov zoo sib npaug (Shfa):
Ntawm no Ai yog thaj tsam ntawm carbide (µm2) thiab Pi yog thaj tsam ntawm carbide (µm) 29.Txhawm rau txheeb xyuas cov theem, hmoov X-ray diffraction (XRD) tau ua los ntawm X-ray diffractometer (Bruker D8 Discover nrog LynxEye 1D strip detector) nrog Co-Kα hluav taws xob (λ = 1.79026 Å).Luam theej duab cov qauv dhau ntawm 2θ thaj tsam ntawm 35 ° txog 130 ° nrog ib kauj ruam loj ntawm 0.02 ° thiab lub sijhawm ua haujlwm ntawm 2 vib nas this.Cov ntaub ntawv XRD tau txheeb xyuas siv Diffract.EVA software, uas hloov kho cov ntaub ntawv crystallographic hauv 2021. Tsis tas li ntawd, Vickers hardness tester (Struers Durascan 80, Austria) tau siv los txiav txim qhov microhardness.Raws li ASTM E384-17 30 tus qauv, 30 cov ntawv luam tawm tau ua los ntawm metallographically npaj cov qauv hauv 0.35 hli increments rau 10 s ntawm 5 kgf.Cov kws sau ntawv yav dhau los tau qhia txog microstructural nta ntawm HCMTS31.
Lub pob phaj tribometer (Bruker Universal Mechanical Tester Tribolab, Tebchaws USA) tau siv los ua cov kev xeem qhuav reciprocating hnav, kev teeb tsa uas tau piav qhia lwm qhov31.Cov kev xeem tsis muaj raws li hauv qab no: raws li tus qauv 32 ASTM G133-05, load 3 N, zaus 1 Hz, stroke 3 hli, ntev 1 teev.Aluminium oxide npas (Al2O3, raug chav kawm 28 / ISO 3290) nrog txoj kab uas hla ntawm 10 hli nrog macrohardness txog 1500 HV thiab qhov roughness (Ra) txog li 0.05 µm, muab los ntawm Redhill Precision, Czech koom pheej, tau siv los ua counterweights .Kev ntsuas qhov ntsuas tau raug xaiv los tiv thaiv qhov cuam tshuam ntawm oxidation uas tuaj yeem tshwm sim vim qhov sib npaug thiab kom nkag siab zoo dua cov txheej txheem hnav ntawm cov qauv hauv qhov hnyav hnyav.Nws yuav tsum raug sau tseg tias qhov ntsuas ntsuas tsis zoo ib yam li hauv Ref.8 txhawm rau sib piv cov ntaub ntawv hnav nrog cov kev tshawb fawb uas twb muaj lawm.Tsis tas li ntawd, ib qho kev ntsuam xyuas rov ua dua nrog lub nra ntawm 10 N tau ua tiav los xyuas qhov kev ua tau zoo ntawm tribological ntawm cov khoom hnyav dua, thaum lwm qhov kev ntsuas tsis tas li.Kev sib tiv tauj thawj zaug raws li Hertz yog 7.7 MPa thiab 11.5 MPa ntawm 3 N thiab 10 N, feem.Thaum lub sij hawm coj mus kuaj, qhov kev sib txhuam quab yuam raug kaw ntawm qhov zaus ntawm 45 Hz thiab qhov nruab nrab coefficient ntawm kev sib txhuam (CoF) raug xam.Rau txhua qhov kev thauj khoom, peb qhov ntsuas tau raug coj los nyob rau hauv ib puag ncig.
Cov kev coj ua tau raug tshuaj xyuas siv SEM tau piav qhia saum toj no, thiab EMF tsom xam tau ua tiav siv Aztec Acquisition hnav khaub ncaws tsom xam software.Qhov hnav khaub ncaws ntawm lub qhov cub ua ke tau kuaj xyuas siv lub tshuab ntsuas qhov muag (Keyence VHX-5000, Nyiv).Ib lub laser profiler tsis sib cuag (NanoFocus µScan, Lub teb chaws Yelemees) tau tshuaj xyuas cov cim hnav nrog kev daws teeb meem ntsug ntawm ± 0.1 µm raws z axis thiab 5 µm raws x thiab y axes.Daim ntawv qhia hnav caws pliav deg profile tau tsim hauv Matlab® siv x, y, z ua haujlwm tau los ntawm kev ntsuas qhov profile.Ob peb txoj kev coj txoj kev ntsug tau muab rho tawm los ntawm daim ntawv qhia saum npoo profile yog siv los xam qhov hnav ntim poob ntawm txoj kev hnav.Lub ntim poob yog xam raws li cov khoom ntawm qhov nruab nrab ntu ntu ntu ntawm cov hlau profile thiab qhov ntev ntawm kev hnav, thiab cov ntsiab lus ntxiv ntawm cov qauv no tau piav qhia yav dhau los los ntawm cov kws sau ntawv33.Los ntawm no, qhov tshwj xeeb hnav tus nqi (k) tau txais los ntawm cov qauv hauv qab no:
Ntawm no V yog qhov ntim poob vim hnav (mm3), W yog qhov siv load (N), L yog qhov zawv zawg qhov deb (mm), thiab k yog qhov tshwj xeeb hnav tus nqi (mm3 / Nm) 34.Cov ntaub ntawv sib txhuam thiab daim ntawv qhia saum npoo av rau HCMTS suav nrog cov khoom siv ntxiv (Daim duab S1 thiab daim duab S2) los sib piv HCMSS tus nqi hnav.
Nyob rau hauv txoj kev tshawb no, ib daim ntawv qhia kev sib tw hardness ntawm txoj kev hnav tau siv los ua kom pom cov yas deformation tus cwj pwm (piv txwv li kev ua haujlwm hnyav vim kev sib cuag siab) ntawm thaj chaw hnav.Cov qauv polished raug txiav nrog aluminium oxide txiav log ntawm lub tshuab txiav (Struers Accutom-5, Austria) thiab polished nrog SiC xuab zeb qib ntawm 240 txog 4000 P raws li cov thickness ntawm cov qauv.Microhardness ntsuas ntawm 0.5 kgf 10 s thiab 0.1 mm nrug raws li ASTM E348-17.Cov ntawv luam tawm tau muab tso rau ntawm 1.26 × 0.3 mm2 daim phiaj sib npaug kwv yees li 60 µm hauv qab ntawm qhov chaw (Daim duab 1) thiab tom qab ntawd daim duab qhia kev tawv tawv tau ua tiav siv kev cai Matlab® code piav qhia lwm qhov35.Tsis tas li ntawd, qhov microstructure ntawm ntu ntu ntawm qhov chaw hnav tau raug tshuaj xyuas siv SEM.
Schematic ntawm hnav lub cim qhia qhov chaw ntawm tus ntoo khaub lig seem (a) thiab ib qho kev kho qhov muag micrograph ntawm daim ntawv qhia hardness qhia cov cim qhia nyob rau hauv seem (b).
Lub microstructure ntawm HCMSS kho nrog ELP muaj xws li ib tug homogeneous carbide network ncig los ntawm ib tug matrix (Fig. 2a, b).EDX tsom xam pom tias grey thiab tsaus carbides yog chromium thiab vanadium nplua nuj carbides, raws li (Table 1).Muab xam los ntawm cov duab tsom xam, qhov ntim feem ntawm carbides yog kwv yees li ~ 22.5% (~ 18.2% siab chromium carbides thiab ~ 4.3% siab vanadium carbides).Qhov nruab nrab grain loj nrog cov qauv sib txawv yog 0.64 ± 0.2 µm thiab 1.84 ± 0.4 µm rau V thiab Cr nplua nuj carbides, raws li (Fig. 2c, d).High V carbides zoo li rounder nrog cov duab zoo (± SD) ntawm li 0.88 ± 0.03 vim qhov zoo tshaj qhov tseem ceeb ze rau 1 sib npaug rau puag ncig carbides.Nyob rau hauv sib piv, siab chromium carbides tsis zoo kawg nkaus puag ncig, nrog ib tug zoo zoo ntawm txog 0.56 ± 0.01, uas tej zaum yuav yog vim agglomeration.Martensite (α, bcc) thiab khaws cia austenite (γ', fcc) diffraction peaks tau kuaj pom ntawm HCMSS X-ray qauv raws li qhia hauv daim duab 2e.Tsis tas li ntawd, X-ray qauv qhia pom muaj cov carbide theem nrab.High chromium carbides tau raug txheeb xyuas tias yog M3C2 thiab M23C6 hom carbides.Raws li cov ntaub ntawv cov ntaub ntawv, 36,37,38 diffraction peaks ntawm VC carbides tau sau tseg ntawm ≈43° thiab 63°, qhia tias VC peaks tau npog los ntawm M23C6 peaks ntawm chromium-nplua nuj carbides (Fig. 2e).
Microstructure ntawm high-carbon martensitic stainless hlau kho nrog EBL (a) ntawm qis magnification thiab (b) ntawm siab magnification, qhia chromium thiab vanadium nplua nuj carbides thiab stainless hlau matrix (electron backscattering hom).Bar graphs qhia qhov loj me me faib ntawm chromium-nplua nuj (c) thiab vanadium-nplua nuj (d) carbides.X-ray qauv qhia pom muaj martensite, khaws cia austenite thiab carbides hauv microstructure (d).
Qhov nruab nrab microhardness yog 625.7 + 7.5 HV5, uas qhia ib tug kuj hardness piv rau conventionally tiav martensitic stainless hlau (450 HV) 1 tsis muaj kev kho cua sov.Cov nanoindentation hardness ntawm siab V carbides thiab siab Cr carbides tau tshaj tawm tias nyob nruab nrab ntawm 12 thiab 32.5 GPa39 thiab 13-22 GPa40, feem.Yog li, lub siab tawv ntawm HCMSS kho nrog ELP yog vim muaj cov ntsiab lus carbon siab, uas txhawb kev tsim cov carbide network.Yog li, HSMSS kho nrog ELP qhia tau hais tias zoo microstructural yam ntxwv thiab hardness yam tsis muaj kev kho mob tom qab thermal ntxiv.
Curves ntawm qhov nruab nrab coefficient ntawm kev sib txhuam (CoF) rau cov qauv ntawm 3 N thiab 10 N yog nthuav tawm nyob rau hauv daim duab 3, qhov ntau ntawm qhov tsawg kawg nkaus thiab qhov siab tshaj qhov sib txhuam qhov tseem ceeb yog cim nrog translucent shading.Txhua qhov nkhaus qhia tau hais tias lub sijhawm khiav thiab lub xeev khov kho.Kev khiav-hauv theem xaus ntawm 1.2 m nrog CoF (± SD) ntawm 0.41 ± 0.24.3 N thiab ntawm 3.7 m nrog CoF ntawm 0.71 ± 0.16.10 N, ua ntej nkag mus rau theem ruaj khov thaum kev sib txhuam nres.tsis hloov sai.Vim yog qhov chaw me me thiab qhov tsis zoo ntawm cov yas pib deformation, kev sib txhuam quab yuam tau nce sai heev thaum lub sij hawm khiav-hauv theem ntawm 3 N thiab 10 N, qhov twg muaj kev sib txhuam ntau dua thiab qhov zawv zawg ntev dua tshwm sim ntawm 10 N, uas tej zaum yuav yog vim rau qhov tseeb tias Piv nrog 3 N, qhov kev puas tsuaj saum npoo yog siab dua.Rau 3 N thiab 10 N, CoF qhov tseem ceeb nyob rau hauv qhov chaw nres tsheb yog 0.78 ± 0.05 thiab 0.67 ± 0.01, feem.CoF xyaum ua haujlwm ruaj khov ntawm 10 N thiab maj mam nce ntawm 3 N. Hauv cov ntaub ntawv txwv, CoF ntawm L-PBF kho stainless hlau piv rau cov tshuaj tiv thaiv ceramic ntawm cov khoom siv tsawg ntawm 0.5 txog 0.728, 20, 42, uas yog nyob rau hauv kev pom zoo zoo nrog ntsuas CoF qhov tseem ceeb hauv txoj kev tshawb no.Qhov txo qis hauv CoF nrog kev nce ntxiv hauv lub xeev khov kho (kwv yees li 14.1%) tuaj yeem raug ntaus nqi rau qhov degradation tshwm sim ntawm qhov sib cuam tshuam ntawm qhov hnav khaub ncaws thiab cov khoom sib txuas, uas yuav tau tham ntxiv hauv ntu tom ntej los ntawm kev tsom xam ntawm qhov chaw ntawm qhov chaw. hnav cov qauv.
Kev sib txhuam coefficients ntawm VSMSS cov qauv kho nrog ELP ntawm txoj kev zawv zawg ntawm 3 N thiab 10 N, ib theem nyob ruaj khov yog cim rau txhua qhov nkhaus.
Qhov tshwj xeeb hnav tus nqi ntawm HKMS (625.7 HV) yog kwv yees ntawm 6.56 ± 0.33 × 10–6 mm3 / Nm thiab 9.66 ± 0.37 × 10–6 mm3 / Nm ntawm 3 N thiab 10 N, raws li (Fig.. 4).Yog li, tus nqi hnav nce nrog nce load, uas yog qhov pom zoo nrog cov kev tshawb fawb uas twb muaj lawm ntawm austenite kho nrog L-PBF thiab PH SS17,43.Nyob rau hauv tib lub tribological tej yam kev mob, tus coj tus nqi ntawm 3 N yog hais txog ib feem tsib uas rau austenitic stainless hlau kho nrog L-PBF (k = 3.50 ± 0.3 × 10–5 mm3 / Nm, 229 HV), raws li nyob rau hauv cov ntaub ntawv dhau los .8. Tsis tas li ntawd, qhov hnav tus nqi ntawm HCMSS ntawm 3 N yog qhov qis dua li cov khoom siv austenitic stainless hlau thiab, tshwj xeeb tshaj yog, siab dua cov isotropic pressed (k = 4.20 ± 0.3 × 10–5 mm3)./Nm, 176 HV) thiab nrum (k = 4.70 ± 0.3 × 10–5 mm3 / Nm, 156 HV) machined austenitic stainless hlau, 8, raws li.Piv nrog rau cov kev tshawb fawb no hauv cov ntaub ntawv, kev txhim kho kev hnav tsis kam ntawm HCMSS yog vim muaj cov ntsiab lus carbon siab thiab tsim cov carbide network uas ua rau muaj zog ntau dua li cov khoom siv austenitic stainless steels conventionally machined.Txhawm rau kawm ntxiv txog qhov hnav ntawm HCMSS cov qauv, ib qho zoo sib xws machined high carbon martensitic tool steel (HCMTS) specimen (nrog hardness ntawm 790 HV) tau sim nyob rau hauv cov xwm txheej zoo sib xws (3 N thiab 10 N) rau kev sib piv;Cov khoom siv ntxiv yog HCMTS Daim Ntawv Qhia Nto Profile (Cov Duab Ntxiv S2).HCMSS coj tus nqi (k = 6.56 ± 0.34 × 10–6 mm3 / Nm) yuav luag tib yam li HCMTS ntawm 3 N (k = 6.65 ± 0.68 × 10–6 mm3 / Nm), uas qhia tau hais tias zoo heev hnav tsis kam. .Cov yam ntxwv no feem ntau yog los ntawm microstructural nta ntawm HCMSS (piv txwv li cov ntsiab lus carbide siab, qhov loj, cov duab thiab kev faib tawm ntawm carbide hais hauv matrix, raws li tau piav qhia hauv Tshooj 3.1).Raws li yav dhau los tau tshaj tawm 31,44, cov ntsiab lus carbide cuam tshuam rau qhov dav thiab qhov tob ntawm kev hnav caws pliav thiab cov txheej txheem ntawm micro-abrasive hnav.Txawm li cas los xij, cov ntsiab lus carbide tsis txaus los tiv thaiv qhov tuag ntawm 10 N, ua rau muaj kev hnav ntau ntxiv.Hauv ntu nram qab no, hnav qhov chaw morphology thiab topography yog siv los piav qhia txog kev hnav thiab deformation mechanisms uas cuam tshuam rau tus nqi hnav ntawm HCMSS.Ntawm 10 N, qhov hnav tus nqi ntawm VCMSS (k = 9.66 ± 0.37 × 10–6 mm3 / Nm) yog siab dua li ntawm VKMTS (k = 5.45 ± 0.69 × 10–6 mm3 / Nm).Ntawm qhov tsis sib xws, cov nqi hnav no tseem siab heev: nyob rau hauv cov xwm txheej zoo sib xws, qhov hnav ntawm cov txheej txheem raws li chromium thiab stellite yog qis dua li ntawm HCMSS45,46.Thaum kawg, vim lub siab hardness ntawm alumina (1500 HV), mating hnav tus nqi yog negligible thiab pom cov cim ntawm cov ntaub ntawv hloov los ntawm cov qauv mus rau txhuas pob.
Kev hnav tshwj xeeb hauv ELR machining ntawm high carbon martensitic stainless hlau (HMCSS), ELR machining ntawm siab carbon martensitic cuab yeej hlau (HCMTS) thiab L-PBF, casting thiab siab isotropic nias (HIP) machining ntawm austenitic stainless hlau (316LSS) ntawm ntau daim ntawv thov ceev yog loaded.Lub scatterplot qhia tau hais tias tus qauv sib txawv ntawm qhov ntsuas.Cov ntaub ntawv rau austenitic stainless hlau yog muab los ntawm 8.
Txawm hais tias hardfacings xws li chromium thiab stellite tuaj yeem muab kev hnav zoo dua li cov tshuab ua kom zoo dua qub, cov khoom siv ntxiv tuaj yeem (1) txhim kho microstructure, tshwj xeeb tshaj yog rau cov khoom siv nrog ntau yam ntom ntom.kev ua haujlwm ntawm qhov kawg;thiab (3) tsim cov tshiab nto topologies xws li kev sib xyaw ua kua dej dynamic bearings.Tsis tas li ntawd, AM muaj cov qauv tsim geometric yooj yim.Txoj kev tshawb no tshwj xeeb yog qhov tshiab thiab tseem ceeb heev vim nws yog ib qho tseem ceeb los qhia txog cov yam ntxwv ntawm cov hlau uas tau tsim tshiab nrog EBM, uas cov ntaub ntawv tam sim no muaj tsawg heev.
Lub morphology ntawm hnav nto thiab morphology ntawm cov qauv hnav ntawm 3 N yog qhia nyob rau hauv daim duab.5, qhov tseem ceeb hnav mechanism yog abrasion tom qab oxidation.Ua ntej, cov hlau substrate yog plastically deformed thiab ces muab tshem tawm los ua grooves 1 mus rau 3 µm sib sib zog nqus, raws li qhia nyob rau hauv lub nto profile (Fig. 5a).Vim yog cov cua kub sib txhuam tsim los ntawm kev zawv zawg tas li, cov khoom tshem tawm tseem nyob ntawm qhov sib cuam tshuam ntawm cov txheej txheem tribological, tsim cov txheej txheem tribological uas muaj cov kob me me ntawm cov hlau oxide nyob ib puag ncig siab chromium thiab vanadium carbides (Daim duab 5b thiab Table 2).), raws li tau tshaj tawm rau austenitic stainless hlau kho nrog L-PBF15,17.Ntawm daim duab.5c qhia tau tias khaus oxidation tshwm sim nyob rau hauv nruab nrab ntawm cov caws pliav.Yog li, kev tsim cov txheej txheem kev sib txhuam yog yooj yim los ntawm kev puas tsuaj ntawm cov txheej txheem kev sib txhuam (piv txwv li, oxide txheej) (Fig. 5f) los yog tshem tawm cov khoom tshwm sim nyob rau hauv qhov chaw tsis muaj zog nyob rau hauv lub microstructure, yog li accelerating lub tshem tawm ntawm cov khoom.Nyob rau hauv ob qho tib si, kev puas tsuaj ntawm kev sib txhuam txheej ua rau tsim cov khoom hnav ntawm qhov sib cuam tshuam, uas tej zaum yuav yog vim li cas rau qhov kev nyiam ntawm CoF nce hauv lub xeev khov kho 3N (Daim duab 3).Tsis tas li ntawd, muaj cov cim qhia ntawm peb feem coj los ntawm cov oxides thiab cov khoom xoob xoob ntawm qhov hnav, uas thaum kawg ua rau tsim cov micro-scratches ntawm lub substrate (Fig. 5b, e) 9,12,47.
Nto profile (a) thiab photomicrographs (b-f) ntawm qhov hnav nto morphology ntawm high-carbon martensitic stainless hlau kho nrog ELP ntawm 3 N, hla ntu ntawm cov cim coj hauv BSE hom (d) thiab kho qhov muag microscopy ntawm hnav nto ntawm 3 N (g) alumina spheres.
Slip bands tsim rau ntawm cov hlau substrate, qhia cov yas deformation vim hnav (Fig. 5e).Cov txiaj ntsig zoo sib xws kuj tau txais hauv kev tshawb fawb txog kev coj cwj pwm ntawm SS47 austenitic steel kho nrog L-PBF.Lub reorientation ntawm vanadium-nplua nuj carbides kuj qhia cov yas deformation ntawm cov hlau matrix thaum zawv zawg (Fig. 5e).Micrographs ntawm tus ntoo khaub lig ntawm cov cim coj qhia pom tias muaj cov pits me me puag ncig los ntawm microcracks (Fig. 5d), uas tej zaum yuav yog vim cov yas deformation ntau dhau ze ntawm qhov chaw.Cov ntaub ntawv hloov mus rau aluminium oxide spheres raug txwv, thaum lub spheres tseem nyob ruaj khov (Fig. 5g).
Qhov dav thiab qhov tob ntawm kev hnav ntawm cov qauv tau nce nrog nce load (ntawm 10 N), raws li qhia hauv daim ntawv qhia saum toj kawg nkaus (Fig. 6a).Abrasion thiab oxidation tseem yog qhov tseem ceeb ntawm cov txheej txheem hnav, thiab qhov nce ntawm cov micro-scratches ntawm kev coj ua qhia tau hais tias peb feem hnav kuj tshwm sim ntawm 10 N (Fig. 6b).EDX tsom xam pom qhov tsim ntawm cov hlau nplua nuj oxide Islands tuaj.Lub Al peaks nyob rau hauv lub spectra tau lees paub tias qhov kev hloov ntawm cov khoom los ntawm cov counterparty mus rau cov qauv tshwm sim ntawm 10 N (Fig. 6c thiab Table 3), thaum nws tsis tau soj ntsuam ntawm 3 N (Table 2).Peb lub cev hnav yog tshwm sim los ntawm hnav cov khoom los ntawm oxide Islands tuaj thiab cov analogs, qhov kev soj ntsuam ntxaws EDX qhia txog cov khoom nqa los ntawm cov analogs (Cov duab ntxiv S3 thiab Table S1).Txoj kev loj hlob ntawm oxide Islands tuaj yog txuam nrog cov pits sib sib zog nqus, uas kuj tau pom nyob rau hauv 3N (Fig. 5).Cracking thiab fragmentation ntawm carbides feem ntau tshwm sim nyob rau hauv carbides nplua nuj nyob rau hauv 10 N Cr (Fig. 6e, f).Tsis tas li ntawd, siab V carbides flake thiab hnav ib puag ncig matrix, uas nyob rau hauv lem ua rau peb feem hnav.Ib lub qhov dej zoo sib xws hauv qhov loj thiab zoo li qhov siab V carbide (qhov tseem ceeb hauv lub voj voog liab) kuj tshwm sim hauv ntu ntu ntawm txoj kev khiav (Fig. 6d) (saib carbide loj thiab cov duab tsom xam. 3.1), qhia tias qhov siab V. carbide V tuaj yeem flake tawm ntawm matrix ntawm 10 N. Cov duab puag ncig ntawm siab V carbides txhawb nqa cov nyhuv rub, thaum agglomerated siab Cr carbides yog nquag tawg (Fig. 6e, f).Tus cwj pwm tsis ua hauj lwm no qhia tau hais tias cov matrix tau dhau nws lub peev xwm los tiv thaiv cov yas deformation thiab cov microstructure tsis muaj kev cuam tshuam txaus ntawm 10 N. Ntsug tawg nyob rau hauv qhov chaw (Fig. 6d) qhia qhov siv ntawm cov yas deformation uas tshwm sim thaum zawv zawg.Raws li kev thauj khoom nce ntxiv muaj kev hloov pauv ntawm cov khoom siv los ntawm kev hnav mus rau lub pob alumina (Daim duab 6g), uas tuaj yeem nyob ruaj khov ntawm 10 N. Qhov laj thawj tseem ceeb rau kev txo qis hauv CoF qhov tseem ceeb (Fig. 3).
Nto profile (a) thiab photomicrographs (b-f) ntawm hnav nto topography (b-f) ntawm high-carbon martensitic stainless hlau kho nrog EBA ntawm 10 N, coj taug kev hla ntu hauv BSE hom (d) thiab optical microscope nto ntawm alumina sphere ntawm 10 N (g).
Thaum zawv zawg hnav, qhov saum npoo yog raug rau cov tshuaj tiv thaiv-induced compressive thiab shear stresses, uas ua rau cov yas deformation tseem ceeb nyob rau hauv lub hnav nto34,48,49.Yog li ntawd, kev ua hauj lwm hardening tuaj yeem tshwm sim hauv qab qhov chaw vim yog cov yas deformation, cuam tshuam rau kev hnav thiab deformation mechanisms uas txiav txim siab coj tus cwj pwm ntawm cov khoom.Yog li ntawd, hla ntu hardness daim ntawv qhia (raws li tau piav qhia hauv Tshooj 2.4) tau ua nyob rau hauv txoj kev tshawb no los txiav txim qhov kev txhim kho ntawm cov yas deformation zone (PDZ) hauv qab txoj kev hnav raws li kev ua haujlwm ntawm kev thauj khoom.Txij li thaum, raws li tau hais nyob rau hauv cov seem dhau los, cov cim qhia meej ntawm cov yas deformation tau pom hauv qab ntawm qhov hnav (Daim duab 5d, 6d), tshwj xeeb tshaj yog ntawm 10 N.
Ntawm daim duab.Daim duab 7 qhia txog kev sib tw hardness daim duab ntawm cov cim ntawm HCMSS kho nrog ELP ntawm 3 N thiab 10 N. Nws yog ib qho tsim nyog sau cia tias cov nqi hardness no tau siv los ua qhov ntsuas los ntsuas cov txiaj ntsig ntawm kev ua haujlwm hardening.Qhov kev hloov ntawm hardness hauv qab lub cim coj yog los ntawm 667 mus rau 672 HV ntawm 3 N (Fig. 7a), qhia tias kev ua hauj lwm hardening yog negligible.Piv txwv li, vim qhov kev daws teeb meem tsawg ntawm daim ntawv qhia microhardness (piv txwv li qhov kev ncua deb ntawm cov cim), cov txheej txheem siv hardness ntsuas tsis tuaj yeem kuaj pom cov kev hloov ntawm hardness.Ntawm qhov tsis sib xws, PDZ cov cheeb tsam nrog cov nqi hardness ntawm 677 txog 686 HV nrog qhov siab tshaj plaws ntawm 118 µm thiab qhov ntev ntawm 488 µm tau pom ntawm 10 N (Fig. 7b), uas cuam tshuam nrog qhov dav ntawm txoj kev hnav ( Fig. 6a)).Cov ntaub ntawv zoo sib xws ntawm PDZ qhov hloov pauv loj nrog kev thauj khoom tau pom nyob rau hauv kev tshawb fawb hnav ntawm SS47 kho nrog L-PBF.Cov txiaj ntsig tau pom tias muaj cov austenite khaws cia muaj feem cuam tshuam rau cov ductility ntawm additively fabricated steels 3, 12, 50, thiab khaws cia austenite hloov mus rau hauv martensite thaum lub sij hawm yas deformation (yas nyhuv ntawm theem transformation), uas txhim kho cov hauj lwm hardening ntawm cov hlau.steel 51. Txij li cov qauv VCMSS muaj khaws cia austenite raws li X-ray diffraction qauv tau tham ua ntej (Daim duab 2e), nws tau pom tias khaws cia austenite hauv microstructure tuaj yeem hloov mus rau hauv martensite thaum sib cuag, yog li ua kom lub hardness ntawm PDZ ( Ib. 7b).Tsis tas li ntawd, qhov kev tsim ntawm plam tshwm sim ntawm kev hnav (Daim duab 5e, 6f) kuj qhia tau tias cov yas deformation tshwm sim los ntawm dislocation slip nyob rau hauv qhov kev txiav txim ntawm shear stress ntawm zawv zawg sib cuag.Txawm li cas los xij, qhov kev nyuab siab shear tshwm sim ntawm 3 N tsis txaus los tsim qhov siab dislocation ceev los yog kev hloov pauv ntawm cov khaws cia austenite rau martensite pom los ntawm txoj kev siv, yog li kev ua haujlwm hardening tsuas yog pom ntawm 10 N (Fig. 7b).
Hla-sectional hardness daim duab ntawm hnav lem ntawm high-carbon martensitic stainless hlau raug hluav taws xob tawm machining ntawm 3 N (a) thiab 10 N (b).
Txoj kev tshawb no qhia txog kev coj tus cwj pwm thiab microstructural yam ntxwv ntawm ib tug tshiab high carbon martensitic stainless hlau kho nrog ELR.Kev kuaj hnav qhuav tau ua tiav nyob rau hauv zawv zawg nyob rau hauv ntau yam kev thauj khoom, thiab cov qauv hnav tau kuaj xyuas siv electron microscopy, laser profileometer thiab hardness maps ntawm cross-section ntawm hnav lem.
Kev tsom xam Microstructural tau qhia txog kev faib tawm ntawm cov carbides nrog cov ntsiab lus siab ntawm chromium (~ 18.2% carbides) thiab vanadium (~ 4.3% carbides) hauv cov matrix ntawm martensite thiab khaws cia austenite nrog microhardness siab.Cov txheej txheem hnav tseem ceeb yog hnav thiab oxidation ntawm cov khoom qis, thaum peb lub cev hnav los ntawm kev ncab siab-V carbides thiab xoob nplej oxides kuj tseem ua rau hnav thaum nce loads.Tus nqi coj yog zoo dua li L-PBF thiab cov pa machined austenitic stainless hlau, thiab txawm zoo ib yam li EBM machined cuab yeej steels ntawm tsawg loads.Tus nqi CoF txo qis nrog kev nce ntxiv vim qhov hloov ntawm cov khoom mus rau lub cev rov qab.Siv txoj kev hla-sectional hardness mapping txoj kev, cov yas deformation cheeb tsam tau qhia hauv qab cov cim hnav.Muaj peev xwm ua kom zoo dua qub thiab theem hloov pauv hauv matrix tuaj yeem tshawb xyuas ntxiv siv electron backscatter diffraction kom nkag siab zoo dua qhov cuam tshuam ntawm kev ua haujlwm hardening.Qhov kev daws teeb meem tsawg ntawm daim ntawv qhia microhardness tsis tso cai rau kev pom ntawm qhov hnyav ntawm qhov hnyav ntawm cov khoom siv qis, yog li nanoindentation tuaj yeem muab kev daws teeb meem siab dua qhov hloov pauv siv tib txoj kev.
Txoj kev tshawb no nthuav tawm thawj zaug kev tshuaj ntsuam xyuas ntawm kev hnav tsis kam thiab kev sib txhuam ntawm cov pa roj carbon martensitic stainless hlau tshiab kho nrog ELR.Xav txog qhov kev ywj pheej ntawm geometric tsim ntawm AM thiab qhov muaj peev xwm ntawm kev txo cov kauj ruam machining nrog AM, qhov kev tshawb fawb no tuaj yeem ua txoj hauv kev rau kev tsim cov khoom tshiab no thiab nws siv rau hauv cov khoom siv los ntawm cov shafts rau cov yas txhaj tshuaj pwm nrog cov khoom txias txias.
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