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ASTM A240 304 316 Chitsulo Chopanda chitsulo Chapakati Chochindikira mbale Ikhoza Kudulidwa Ndi Kupanga Makonda Mtengo Wa Fakitale Ya China

Gulu lazinthu: 201/304/304l/316/316l/321/309s/310s/410/420/430/904l/2205/2507
Mtundu: Ferritic, Austenite, Martensite, Duplex
Ukadaulo: Wozizira Wozizira komanso Wowotcha
Zitsimikizo: ISO9001, CE, SGS chaka chilichonse
Utumiki: Kuyesa kwa gulu lachitatu
Kutumiza: mkati mwa masiku 10-15 kapena kuganizira kuchuluka kwake

Chitsulo chosapanga dzimbiri ndi aloyi yachitsulo yomwe imakhala ndi Chromium yochepera 10.5 peresenti.Zomwe zili mu Chromium zimapanga filimu yopyapyala ya chromium oxide pamwamba pazitsulo yotchedwa passivation layer.Chosanjikizachi chimalepheretsa kuti dzimbiri zisachitike pazitsulo;Kuchuluka kwa Chromium muzitsulo, kumapangitsanso kukana kwa dzimbiri.

Chitsulocho chimakhalanso ndi zinthu zina zosiyanasiyana monga Carbon, Silicon ndi Manganese.Zinthu zina zitha kuwonjezeredwa kuti ziwonjezere kukana kwa dzimbiri (Nickel) ndi mawonekedwe (Molybdenum).

Khalidwe la high carbon martensitic stainless steel (HCMSS) lokhala ndi pafupifupi 22.5 vol.% ma carbides okhala ndi chromium (Cr) ndi vanadium (V) wambiri adakhazikitsidwa ndi electron beam melting (EBM).Microstructure imapangidwa ndi magawo a martensite ndi otsalira austenite, submicron high V ndi micron high Cr carbides amagawidwa mofanana, ndipo kuuma kwake kumakhala kwakukulu.CoF imatsika ndi pafupifupi 14.1% ndikuchulukirachulukira kokhazikika chifukwa cha kusamutsa zinthu kuchokera panjanji yowonongeka kupita ku gulu lotsutsa.Poyerekeza ndi zida za martensitic zomwe zimagwiritsidwa ntchito mofananamo, mavalidwe a HCMSS ndi ofanana ndi katundu wochepa.Makina ovala kwambiri ndikuchotsa matrix achitsulo ndi abrasion ndikutsatiridwa ndi makutidwe ndi okosijeni pamavalidwe, pomwe ma abrasive amitundu itatu amachitika ndi kuchuluka kwa katundu.Magawo opindika apulasitiki pansi pa chiwopsezo chodziwikiratu ndi mapu olimba a magawo.Zochitika zenizeni zomwe zimachitika pamene mavalidwe akuchulukirachulukira amafotokozedwa ngati kusweka kwa carbide, vanadium carbide tearout yayikulu, ndi kufa kusweka.Kafukufukuyu akuwunikira mawonekedwe ovala a HCMSS opangira zowonjezera, zomwe zitha kutsegulira njira yopangira zida za EBM pazovala kuyambira ma shaft kupita ku nkhungu zamajekeseni apulasitiki.
Chitsulo chosapanga dzimbiri (SS) ndi banja losinthasintha lazitsulo zomwe zimagwiritsidwa ntchito kwambiri muzamlengalenga, magalimoto, chakudya ndi ntchito zina zambiri chifukwa cha kukana kwawo kwa dzimbiri komanso makina oyenera1,2,3.Kukana kwawo kwa dzimbiri chifukwa cha kuchuluka kwa chromium (kuposa 11.5 wt. %) mu HC, zomwe zimathandiza kupanga filimu ya oxide yokhala ndi chromium yapamwamba pamwamba1.Komabe, magiredi ambiri azitsulo zosapanga dzimbiri amakhala ndi mpweya wochepa kwambiri ndipo chifukwa chake amakhala ndi kuuma pang'ono komanso kukana kuvala, zomwe zimapangitsa kuti pakhale moyo wautumiki wocheperako pazida zokhudzana ndi kuvala monga zida zofikira mumlengalenga4.Nthawi zambiri amakhala ndi kuuma kochepa (kuyambira 180 mpaka 450 HV), zitsulo zosapanga dzimbiri za martensitic zomwe zimatenthedwa ndizomwe zimakhala zolimba kwambiri (mpaka 700 HV) komanso zokhala ndi mpweya wambiri (mpaka 1.2 wt%), zomwe zimatha kuthandizira kupanga martensite.1. Mwachidule, kuchuluka kwa mpweya wa carbon kumachepetsa kutentha kwa kusintha kwa martensitic, zomwe zimapangitsa kuti pakhale mawonekedwe a martensitic microstructure ndi kupeza microstructure yosamva kuvala pamitengo yozizira kwambiri.Magawo olimba (mwachitsanzo, ma carbides) amatha kuwonjezeredwa ku matrix achitsulo kuti apititse patsogolo kukana kwakufa.
Kukhazikitsidwa kwa zopangira zowonjezera (AM) kumatha kupanga zida zatsopano zokhala ndi mawonekedwe omwe mukufuna, mawonekedwe a microstructural, komanso makina apamwamba kwambiri5,6.Mwachitsanzo, kusungunula kwa bedi la ufa (PBF), imodzi mwa njira zowotcherera zomwe zimagulitsidwa kwambiri, zimaphatikizapo kuyika kwa ufa wopangidwa kale kuti apange magawo owoneka bwino posungunula ufawo pogwiritsa ntchito magwero a kutentha monga ma lasers kapena ma elekitironi7.Kafukufuku wambiri wasonyeza kuti zitsulo zosapanga dzimbiri zopangidwa ndi makina owonjezera zimatha kuchita bwino kuposa zida zopangidwa kale.Mwachitsanzo, zitsulo zosapanga dzimbiri za austenitic zomwe zimagwiritsidwa ntchito zowonjezera zasonyezedwa kuti zili ndi makina apamwamba kwambiri chifukwa cha microstructure yawo yabwino (ie, maubwenzi a Hall-Petch)3,8,9.Kuchiza kutentha kwa AM-treated ferritic stainless steel stainless steel kumapanga ma precipitates owonjezera omwe amapereka makina amakina ofanana ndi omwe amafanana nawo3,10.Chitsulo chosapanga dzimbiri chopangidwa ndi magawo awiri okhala ndi mphamvu zambiri komanso kuuma, chokonzedwa ndi makonzedwe owonjezera, pomwe makina opangidwa bwino amapangidwa chifukwa cha magawo olemera a chromium mu microstructure11.Kuonjezera apo, makina opangidwa ndi zowonjezera zowonjezera martensitic ndi PH zosapanga dzimbiri zosapanga dzimbiri angapezeke poyang'anira kusungidwa kwa austenite mu microstructure ndi optimizing Machining ndi kutentha mankhwala magawo 3,12,13,14.
Mpaka pano, zida za tribological za AM austenitic zitsulo zosapanga dzimbiri zalandira chidwi kwambiri kuposa zitsulo zina zosapanga dzimbiri.Makhalidwe a tribological a laser kusungunuka mu ufa wosanjikiza (L-PBF) wochitidwa ndi 316L anaphunziridwa ngati ntchito ya AM processing magawo.Zasonyezedwa kuti kuchepetsa porosity mwa kuchepetsa kuthamanga kwa sikani kapena kuonjezera mphamvu ya laser kungapangitse kuvala kukana15,16.Li et al.17 anayesedwa youma kutsetsereka kuvala pansi magawo osiyanasiyana (katundu, mafupipafupi ndi kutentha) ndipo anasonyeza kuti kutentha m'chipinda kuvala ndi chachikulu kuvala limagwirira, pamene kuwonjezeka kutsetsereka liwiro ndi kutentha kumalimbikitsa makutidwe ndi okosijeni.Zosanjikiza za oxide zomwe zimapangidwira zimatsimikizira kugwira ntchito kwa chonyamulira, kukangana kumachepa ndi kutentha, ndipo kuchuluka kwa mavalidwe kumawonjezeka pa kutentha kwakukulu.M'maphunziro ena, kuwonjezera kwa TiC18, TiB219, ndi SiC20 tinthu tating'onoting'ono ku L-PBF yothandizidwa ndi 316L masanjidwewo kumathandizira kukana kuvala popanga chiwongolero cholimba chamkangano ndikuwonjezeka kwa gawo la tinthu tating'onoting'ono tolimba.Wosanjikiza woteteza oksidi wawonedwanso mu L-PBF12 yothandizidwa ndi PH chitsulo ndi SS11 duplex zitsulo, zomwe zikuwonetsa kuti kuchepetsa kusungidwa kwa austenite ndi post-kutentha treatment12 kungapangitse kukana kuvala.Monga tafotokozera mwachidule apa, zolembazo zimangoyang'ana kwambiri pakuchita kwa tribological kwa mndandanda wa 316L SS, pomwe palibe chidziwitso chochepa pakuchita kwa tribological kwa mndandanda wazitsulo zosapanga dzimbiri zopangidwa ndi martensitic zokhala ndi mpweya wochuluka kwambiri.
Electron Beam Melting (EBM) ndi njira yofanana ndi L-PBF yomwe imatha kupanga ma microstructures okhala ndi refractory carbides monga high vanadium ndi chromium carbides chifukwa cha kuthekera kwake kofikira kutentha komanso kusanthula mitengo 21, 22. Mabuku omwe alipo pa EBM processing of stainless zitsulo makamaka lolunjika pa kudziwa mulingo woyenera kwambiri ELM processing magawo kupeza microstructure popanda ming'alu ndi pores ndi kusintha makina katundu23, 24, 25, 26, pamene ntchito tribological katundu EBM ankachitira zitsulo zosapanga dzimbiri.Pakalipano, makina ovala azitsulo zosapanga dzimbiri za carbon martensitic zosapanga dzimbiri zomwe zimagwiritsidwa ntchito ndi ELR zaphunziridwa pansi pazifukwa zochepa, ndipo kusinthika kwakukulu kwa pulasitiki kwanenedwa kuti kumachitika pansi pa abrasive (mayeso a sandpaper), youma, ndi mikhalidwe yamatope27.
Kafukufukuyu adafufuza za kulimba kwa chitsulo chosapanga dzimbiri cha carbon martensitic chosapanga dzimbiri chopangidwa ndi ELR pansi pa zowuma zowuma zomwe zafotokozedwa pansipa.Choyamba, mawonekedwe a microstructural adadziwika pogwiritsa ntchito scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction ndi kusanthula zithunzi.Deta yomwe idapezedwa ndi njirazi imagwiritsidwa ntchito ngati maziko owonera machitidwe a tribological kudzera mu mayeso owuma obwereza pansi pa katundu wosiyanasiyana, ndipo pamapeto pake mawonekedwe owoneka bwino amawunikiridwa pogwiritsa ntchito SEM-EDX ndi laser profilometers.Mtengo wa kuvala unayesedwa ndikufananizidwa ndi zitsulo za martensitic zomwe zimagwiritsidwa ntchito mofananamo.Izi zinachitidwa kuti apange maziko ofananitsa dongosolo la SS ili ndi machitidwe ovala omwe amagwiritsidwa ntchito kawirikawiri ndi mtundu womwewo wa chithandizo.Potsirizira pake, mapu apakati a njira yovala amasonyezedwa pogwiritsa ntchito mapu a hardness algorithm omwe amawulula kupunduka kwa pulasitiki komwe kumachitika panthawi yolumikizana.Tikumbukenso kuti mayesero tribological phunziroli anachitidwa kuti amvetse bwino tribological katundu wa zinthu zatsopanozi, osati kutsanzira ntchito yeniyeni.Kafukufukuyu amathandizira kumvetsetsa bwino za tribological properties za chitsulo chatsopano chopangidwa ndi martensitic chosapanga dzimbiri chogwiritsidwa ntchito povala zomwe zimafuna kugwira ntchito m'madera ovuta.
Zitsanzo za high carbon martensitic stainless steel (HCMSS) zothandizidwa ndi ELR pansi pa dzina la Vibenite® 350 zinapangidwa ndikuperekedwa ndi VBN Components AB, Sweden.Zomwe zimapangidwa mwadzina zachitsanzo: 1.9 C, 20.0 Cr, 1.0 Mo, 4.0 V, 73.1 Fe (wt.%).Choyamba, zitsanzo zowuma zowuma (40 mm × 20 mm × 5 mm) zinapangidwa kuchokera ku zitsanzo zamakona anayi (42 mm × 22 mm × 7 mm) popanda chithandizo chilichonse chapambuyo potentha pogwiritsa ntchito makina otulutsa magetsi (EDM).Ndiye zitsanzo zinali motsatizana pansi ndi SiC sandpaper ndi kukula kwa tirigu 240 kuti 2400 R kupeza pamwamba roughness (Ra) pafupifupi 0,15 μm.Kuphatikiza apo, zitsanzo za EBM-treated high-carbon martensitic tool steel (HCMTS) yokhala ndi mankhwala odziwika bwino a 1.5 C, 4.0 Cr, 2.5 Mo, 2.5 W, 4.0 V, 85.5 Fe (wt. .%) (yomwe imadziwika kuti ndi malonda Vibenite® 150) Komanso yokonzedwa chimodzimodzi.HCMTS ili ndi 8% ya ma carbides ndi voliyumu ndipo imagwiritsidwa ntchito kufananiza data ya mavalidwe a HCMSS.
Mawonekedwe a Microstructural a HCMSS adachitidwa pogwiritsa ntchito SEM (FEI Quanta 250, USA) yokhala ndi chowunikira cha X-ray (EDX) XMax80 chochokera ku Oxford Instruments.Zithunzi zitatu zojambulidwa mwachisawawa zomwe zili ndi 3500 µm2 zidatengedwa munjira ya electron (BSE) yobwerera m'mbuyo ndikuwunikidwa pogwiritsa ntchito kusanthula kwazithunzi (ImageJ®) 28 kuti adziwe kagawo kakang'ono (ie gawo la voliyumu), kukula ndi mawonekedwe.Chifukwa cha mawonekedwe owoneka bwino, gawo lachigawo linatengedwa lofanana ndi gawo la voliyumu.Kuphatikiza apo, mawonekedwe a carbides amawerengedwa pogwiritsa ntchito mawonekedwe a equation (Shfa):
Apa Ai ndi gawo la carbide (µm2) ndipo Pi ndiye gawo la carbide (µm)29.Kuti mudziwe magawo, ufa wa X-ray diffraction (XRD) unagwiritsidwa ntchito pogwiritsa ntchito X-ray diffractometer (Bruker D8 Discover ndi LynxEye 1D strip detector) ndi Co-Kα radiation (λ = 1.79026 Å).Jambulani chitsanzo pa 2θ kuyambira 35 ° mpaka 130 ° ndi sitepe ya 0.02 ° ndi sitepe ya 2 masekondi.Deta ya XRD idawunikidwa pogwiritsa ntchito pulogalamu ya Diffract.EVA, yomwe idasinthiratu database ya crystallographic mu 2021. Kuphatikiza apo, Vickers hardness tester (Struers Durascan 80, Austria) idagwiritsidwa ntchito kuti adziwe microhardness.Malinga ndi muyezo wa ASTM E384-17 30, zisindikizo 30 zidapangidwa pazitsanzo zokonzedwa ndi metallographically mu increments 0,35 mm kwa 10 s pa 5 kgf.Olembawo adawonetsa kale mawonekedwe a microstructural a HCMTS31.
Mpira wa tribometer (Bruker Universal Mechanical Tester Tribolab, USA) unagwiritsidwa ntchito poyesa mavalidwe owuma mobwerezabwereza, makonzedwe ake omwe amafotokozedwanso kwina31.Magawo oyeserera ndi awa: molingana ndi muyezo 32 ASTM G133-05, katundu 3 N, pafupipafupi 1 Hz, sitiroko 3 mm, nthawi ya ola limodzi.Mipira ya Aluminium oxide (Al2O3, kalasi yolondola 28/ISO 3290) yokhala ndi mainchesi 10 mm yokhala ndi makulidwe olimba pafupifupi 1500 HV ndi kuuma kwapamtunda (Ra) pafupifupi 0.05 µm, yoperekedwa ndi Redhill Precision, Czech Republic, idagwiritsidwa ntchito ngati zofananira. .Kulinganiza kunasankhidwa kuti ateteze zotsatira za okosijeni zomwe zingachitike chifukwa cha kusanja komanso kumvetsetsa bwino mavalidwe a zitsanzo pansi pamikhalidwe yovuta kwambiri.Tiyenera kuzindikira kuti magawo oyesera ndi ofanana ndi Ref.8 kuti afanizire deta yovala ndi maphunziro omwe alipo.Kuonjezera apo, mayesero angapo obwerezabwereza omwe ali ndi katundu wa 10 N adachitidwa kuti atsimikizire ntchito ya tribological pa katundu wapamwamba, pamene magawo ena oyesera anakhalabe osasinthasintha.Kupanikizika koyambirira kolumikizana ndi Hertz ndi 7.7 MPa ndi 11.5 MPa ku 3 N ndi 10 N, motsatana.Pakuyesa kwa mavalidwe, mphamvu yakukangana idalembedwa pafupipafupi 45 Hz ndipo pafupifupi coefficient of friction (CoF) idawerengedwa.Pa katundu aliyense, miyeso itatu idatengedwa pansi pamikhalidwe yozungulira.
Njira yovala idawunikidwa pogwiritsa ntchito SEM yomwe yafotokozedwa pamwambapa, ndipo kusanthula kwa EMF kunachitika pogwiritsa ntchito pulogalamu ya Aztec Acquisition wear surface analysis software.Pamwamba pa kyubu wophatikizidwawo adawunikidwa pogwiritsa ntchito maikulosikopu (Keyence VHX-5000, Japan).Katswiri wa mbiri ya laser osalumikizana nawo (NanoFocus µScan, Germany) adasanthula chizindikirocho ndikusintha koyima kwa ±0.1 µm motsatira z axis ndi 5 µm motsatira ma ax ndi y.Mapu amtundu wa zipsera zowoneka bwino adapangidwa ku Matlab® pogwiritsa ntchito ma x, y, z ma coordinates omwe adapezeka pamiyezo yambiri.Ma profayilo angapo oyimirira omwe amachotsedwa pamapu apamwamba amagwiritsidwa ntchito kuwerengera kutayika kwa voliyumu pamavalidwe.Kutayika kwa voliyumu kunawerengedwa ngati gawo la magawo ang'onoang'ono a waya komanso kutalika kwa njira yovala, ndipo zina za njirayi zidafotokozedwa kale ndi olemba33.Kuchokera apa, mavalidwe enieni (k) amatengedwa kuchokera munjira iyi:
Apa V ndi kutayika kwa voliyumu chifukwa cha kuvala (mm3), W ndi katundu wogwiritsidwa ntchito (N), L ndi mtunda wotsetsereka (mm), ndi k ndi mlingo wovala (mm3/Nm)34.Deta ya Friction ndi mamapu apamwamba a HCMTS akuphatikizidwa muzowonjezera (Supplementary Figure S1 ndi Chithunzi S2) kuti afananize mavalidwe a HCMSS.
Mu kafukufukuyu, mapu a kuuma kwa magawo ang'onoang'ono a njira yovala anagwiritsidwa ntchito kusonyeza khalidwe la pulasitiki (mwachitsanzo, kuuma kwa ntchito chifukwa cha kupanikizika) kwa malo ovala.Zitsanzo zopukutidwa zidadulidwa ndi gudumu lodulira aluminium oxide pamakina odulira (Struers Accutom-5, Austria) ndikupukutidwa ndi SiC sandpaper kuchokera 240 mpaka 4000 P pamodzi ndi makulidwe a zitsanzo.Muyezo wa Microhardness pa 0.5 kgf 10 s ndi 0.1 mm mtunda molingana ndi ASTM E348-17.Zosindikizazo zinayikidwa pa gridi yamakona anayi pafupifupi 60 µm pansi (Chithunzi 1) kenako mapu olimba adapangidwa pogwiritsa ntchito kachidindo ka Matlab® komwe kafotokozedwe kwina35.Kuphatikiza apo, mawonekedwe ang'onoang'ono a gawo lazovala adawunikidwa pogwiritsa ntchito SEM.
Mapulani a chizindikiro chovala chosonyeza malo a mtanda (a) ndi kuwala kwa micrograph ya mapu olimba omwe akuwonetsa chilemba chomwe chazindikirika pamtanda (b).
The microstructure wa HCMSS ankachitira ndi ELP tichipeza homogeneous carbide network atazunguliridwa ndi masanjidwewo (mkuyu 2a, b).Kusanthula kwa EDX kunawonetsa kuti ma carbides imvi ndi akuda anali chromium ndi vanadium rich carbides, motsatana (Table 1).Powerengedwa kuchokera ku kusanthula kwa zithunzi, gawo la voliyumu ya carbides likuyerekezeredwa kukhala ~ 22.5% (~ 18.2% high chromium carbides ndi ~ 4.3% high vanadium carbides).Avereji yambewu yambewu yokhala ndi zopotoka ndi 0.64 ± 0.2 µm ndi 1.84 ± 0.4 µm ya V ndi Cr rich carbides, motsatana (Mkuyu 2c, d).Ma carbides apamwamba a V amakhala ozungulira okhala ndi mawonekedwe (± SD) pafupifupi 0.88±0.03 chifukwa mawonekedwe amtundu wapafupi ndi 1 amafanana ndi ma carbides ozungulira.Mosiyana ndi izi, ma chromium carbides apamwamba sakhala ozungulira bwino, okhala ndi mawonekedwe pafupifupi 0.56 ± 0.01, omwe angakhale chifukwa cha kuphatikizika.Martensite (α, bcc) ndi kusungidwa kwa austenite (γ ', fcc) nsonga za diffraction zinapezeka pa HCMSS X-ray chitsanzo monga momwe tawonetsera mkuyu 2e.Kuphatikiza apo, mawonekedwe a X-ray akuwonetsa kukhalapo kwa ma carbides achiwiri.Ma chromium carbides apamwamba adadziwika kuti M3C2 ndi M23C6 mtundu wa carbides.Malinga ndi zolemba za mabuku, 36,37,38 diffraction nsonga za VC carbides zinalembedwa pa ≈43 ° ndi 63 °, kutanthauza kuti nsonga za VC zidaphimbidwa ndi nsonga za M23C6 za carbides zolemera za chromium (Mkuyu 2e).
Mipangidwe ya microstructure ya high-carbon martensitic stainless steel chitsulo chosapanga dzimbiri EBL (a) pakukula kochepa ndi (b) pakukula kwapamwamba, kusonyeza chromium ndi vanadium rich carbides ndi matrix zitsulo zosapanga dzimbiri (electron backscattering mode).Ma graph a m'mipiringidzo omwe akuwonetsa kukula kwa tirigu kwa ma carbides olemera kwambiri a chromium (c) ndi vanadium-rich (d).Chitsanzo cha X-ray chimasonyeza kukhalapo kwa martensite, osungidwa austenite ndi carbides mu microstructure (d).
Avereji ya microhardness ndi 625.7 + 7.5 HV5, kusonyeza kuuma kwambiri poyerekeza ndi chitsulo chosapanga dzimbiri cha martensitic (450 HV)1 chopanda kutentha.Kulimba kwa nanoindentation kwa ma V carbides apamwamba ndi ma Cr carbides apamwamba akuti kuli pakati pa 12 ndi 32.5 GPa39 ndi 13-22 GPa40, motsatana.Chifukwa chake, kuuma kwakukulu kwa HCMSS yothandizidwa ndi ELP ndi chifukwa cha kuchuluka kwa kaboni, komwe kumalimbikitsa kupanga network ya carbide.Chifukwa chake, HSMSS yothandizidwa ndi ELP imawonetsa mawonekedwe abwino a microstructural ndi kuuma popanda chithandizo china chilichonse chowonjezera pambuyo pa kutentha.
Ma curve a coefficient of friction (CoF) a zitsanzo pa 3 N ndi 10 N akuwonetsedwa Chithunzi 3, kuchuluka kwa mikangano yocheperako komanso yopitilira muyeso imayikidwa ndi shading yowoneka bwino.Mzere uliwonse umasonyeza gawo lothamanga ndi gawo lokhazikika.Kuthamanga kwapakati kumathera pa 1.2 m ndi CoF (± SD) ya 0.41 ± 0.24.3 N ndi 3.7 m ndi CoF ya 0.71 ± 0.16.10 N, asanalowe mu gawo lokhazikika pamene kukangana kumasiya.sichisintha msanga.Chifukwa cha malo ang'onoang'ono okhudzana ndi mapindikidwe a pulasitiki, mphamvu yowonongeka inakula mofulumira panthawi yothamanga pa 3 N ndi 10 N, kumene mphamvu yothamanga kwambiri ndi mtunda wautali wotsetsereka unachitika pa 10 N, zomwe zingakhale chifukwa. ku mfundo yakuti Poyerekeza ndi 3 N, kuwonongeka kwa pamwamba ndi kwakukulu.Kwa 3 N ndi 10 N, mitengo ya CoF mu gawo loyima ndi 0.78 ± 0.05 ndi 0.67 ± 0.01, motsatana.CoF imakhala yokhazikika pa 10 N ndipo imawonjezeka pang'onopang'ono pa 3 N. M'mabuku ochepa, CoF ya L-PBF imagwiritsa ntchito zitsulo zosapanga dzimbiri poyerekeza ndi matupi a ceramic pamatupi otsika ogwiritsidwa ntchito kuyambira 0.5 mpaka 0.728, 20, 42, omwe ali mu mgwirizano wabwino ndi miyeso ya CoF mu phunziroli.Kuchepa kwa CoF ndi kuchuluka kwa katundu wokhazikika (pafupifupi 14.1%) kungabwere chifukwa cha kuwonongeka kwa nthaka komwe kumachitika pamawonekedwe apakati pawokhawokha ndi mnzakeyo, zomwe zidzakambidwenso mu gawo lotsatira kudzera pakuwunika kwa pamwamba. zitsanzo zakale.
Ma friction coefficients a zitsanzo za VSMSS zothandizidwa ndi ELP pamayendedwe otsetsereka pa 3 N ndi 10 N, gawo loyima limalembedwa pamapindikira aliwonse.
Zovala zenizeni za HKMS (625.7 HV) zimayesedwa pa 6.56 ± 0.33 × 10-6 mm3 / Nm ndi 9.66 ± 0.37 × 10-6 mm3 / Nm pa 3 N ndi 10 N, motero (mkuyu 4).Chifukwa chake, kuchuluka kwa mavalidwe kumawonjezeka ndi kuchuluka kwa katundu, zomwe zimagwirizana bwino ndi maphunziro omwe alipo pa austenite omwe amathandizidwa ndi L-PBF ndi PH SS17,43.Pansi pa tribological mikhalidwe chomwecho, mlingo kuvala pa 3 N ndi pafupifupi gawo limodzi mwa magawo asanu kuti austenitic zosapanga dzimbiri zitsulo zothandizidwa ndi L-PBF (k = 3.50 ± 0.3 × 10-5 mm3/Nm, 229 HV), monga m'mbuyomu. .8. Kuonjezera apo, kuvala kwa HCMSS pa 3 N kunali kochepa kwambiri kusiyana ndi zitsulo zosapanga dzimbiri zosapanga dzimbiri za austenitic ndipo, makamaka, zapamwamba kuposa zoponderezedwa kwambiri za isotropic (k = 4.20 ± 0.3 × 10-5 mm3)./Nm, 176 HV) ndi kuponyedwa (k = 4.70 ± 0.3 × 10–5 mm3/Nm, 156 HV) makina osapanga dzimbiri austenitic, 8, motero.Poyerekeza ndi maphunzirowa m'mabuku, kukana kwamphamvu kwa HCMSS kumayenderana ndi kuchuluka kwa mpweya wa carbon ndi ma carbide network zomwe zimapangitsa kuti zikhale zolimba kwambiri kuposa zitsulo zosapanga dzimbiri za austenitic zomwe zimapangidwira nthawi zonse.Kuti mupitirize kuphunzira kuchuluka kwa mavalidwe a zitsanzo za HCMSS, chitsanzo chofanana cha carbon martensitic tool steel (HCMTS) (chokhala ndi kuuma kwa 790 HV) chinayesedwa pansi pa mikhalidwe yofanana (3 N ndi 10 N) poyerekezera;Zowonjezera ndi HCMTS Surface Profile Map (Supplementary Figure S2).Kuvala kwa HCMSS (k = 6.56 ± 0.34 × 10-6 mm3/Nm) ndi pafupifupi mofanana ndi HCMTS pa 3 N (k = 6.65 ± 0.68 × 10-6 mm3 / Nm), zomwe zimasonyeza kukana kuvala bwino .Makhalidwewa makamaka amachokera ku microstructural mbali za HCMSS (ie high carbide content, size, shape and distribution of carbide particles mu matrix, monga momwe tafotokozera mu Gawo 3.1).Monga tafotokozera kale31,44, zomwe zili ndi carbide zimakhudza m'lifupi ndi kuya kwa chilonda chovala ndi makina ovala a micro-abrasive.Komabe, zomwe zili ndi carbide ndizosakwanira kuteteza kufa pa 10 N, zomwe zimapangitsa kuti mavalidwe achuluke.M'chigawo chotsatirachi, kuvala pamwamba pa morphology ndi topography kumagwiritsidwa ntchito kufotokoza njira zowonongeka ndi zowonongeka zomwe zimakhudza kuvala kwa HCMSS.Pa 10 N, kuvala kwa VCMSS (k = 9.66 ± 0.37 × 10-6 mm3 / Nm) ndipamwamba kuposa VKMTS (k = 5.45 ± 0.69 × 10-6 mm3 / Nm).M'malo mwake, mavalidwe awa akadali okwera kwambiri: pansi pamiyeso yofananira, kuchuluka kwa zokutira zotengera chromium ndi stellite ndizotsika kuposa HCMSS45,46.Pomaliza, chifukwa cha kuuma kwakukulu kwa aluminiyamu (1500 HV), kuchuluka kwa mavalidwe a mating kunali konyozeka ndipo zizindikiro za kusamutsa zinthu kuchokera ku fanizo kupita ku mipira ya aluminiyamu zidapezeka.
Kuvala kwachindunji mu ELR Machining high carbon martensitic stainless steel (HMCSS), ELR Machining high carbon martensitic tool steel (HCMTS) ndi L-PBF, kuponyera ndi high isotropic pressing (HIP) Machining of austenitic stainless steel steel (316LSS) pa ntchito zosiyanasiyana. liwiro amadzazidwa.The scatterplot ikuwonetsa kupotozedwa koyenera kwa miyeso.Zambiri zazitsulo zosapanga dzimbiri za austenitic zimatengedwa kuchokera ku 8.
Ngakhale zolimba monga chromium ndi stellite zimatha kuletsa kuvala bwino kuposa makina a aloyi, makina owonjezera amatha (1) kukonza mawonekedwe ang'onoang'ono, makamaka pazinthu zomwe zimakhala ndi makulidwe osiyanasiyana.ntchito pa mbali yomaliza;ndi (3) kulenga zatsopano pamwamba topology monga Integrated madzimadzi mayendedwe.Kuphatikiza apo, AM imapereka kusinthasintha kwa mapangidwe a geometric.Kafukufukuyu ndiwatsopano komanso wofunikira chifukwa ndikofunikira kuti tifotokozere za kavalidwe kazitsulo zazitsulo zomwe zangopangidwa kumene ndi EBM, zomwe zolemba zapano ndizochepa kwambiri.
Mapangidwe a malo owonongeka ndi morphology ya zitsanzo zowonongeka pa 3 N zikuwonetsedwa mkuyu.5, pomwe njira yayikulu yovala ndi abrasion yotsatiridwa ndi okosijeni.Choyamba, gawo lapansi lachitsulo ndi lopunduka ndi pulasitiki kenako limachotsedwa kuti lipange ma grooves 1 mpaka 3 µm kuya, monga momwe tawonera pamwamba (mkuyu 5a).Chifukwa cha kutentha kwapang'onopang'ono komwe kumapangidwa ndi kutsetsereka kosalekeza, zinthu zomwe zimachotsedwa zimakhalabe pamawonekedwe a tribological system, kupanga gawo la tribological lomwe lili ndi zisumbu zazing'ono zachitsulo chachitsulo chozungulira chromium ndi vanadium carbides (Chithunzi 5b ndi Gulu 2).), monga momwe adaneneranso zitsulo zosapanga dzimbiri za austenitic zomwe zimagwiritsidwa ntchito ndi L-PBF15,17.Pa mkuyu.5c ikuwonetsa makutidwe ndi okosijeni kwambiri omwe amapezeka pakatikati pa chilonda.Choncho, mapangidwe a mkangano wosanjikiza amathandizidwa ndi kuwonongedwa kwa kusanjikizana (ie, oxide wosanjikiza) (mkuyu 5f) kapena kuchotsedwa kwa zinthu kumachitika m'madera ofooka mkati mwa microstructure, motero kufulumizitsa kuchotsa zinthu.Muzochitika zonsezi, kuwonongedwa kwa kusanjikizana kumayambitsa kupanga mapangidwe a zovala pa mawonekedwe, zomwe zingakhale chifukwa cha chizolowezi chowonjezeka cha CoF mu 3N (mkuyu 3).Kuonjezera apo, pali zizindikiro za kuvala kwa magawo atatu omwe amayamba chifukwa cha oxides ndi tinthu tating'onoting'ono tating'onoting'ono timene timavala, zomwe pamapeto pake zimabweretsa kupanga ma micro-scratches pa gawo lapansi (Mkuyu 5b, e) 9,12,47.
Mbiri yapamwamba (a) ndi zithunzithunzi (b-f) za mavalidwe apamwamba a zitsulo zosapanga dzimbiri za carbon martensitic zosapanga dzimbiri zothiridwa ndi ELP pa 3 N, gawo lalikulu la mavalidwe amtundu wa BSE (d) ndi maikrosikopu owoneka bwino a kuvala. pamwamba pa 3 N (g) zigawo za alumina.
Magulu otsekemera opangidwa pazitsulo zachitsulo, zomwe zimasonyeza kusinthika kwa pulasitiki chifukwa cha kuvala (mkuyu 5e).Zotsatira zofananazi zinapezedwanso pakufufuza kwa mavalidwe a SS47 austenitic steel omwe amathandizidwa ndi L-PBF.Kukonzanso kwa vanadium-rich carbides kumasonyezanso kusinthika kwa pulasitiki kwa matrix achitsulo panthawi yothamanga (Mkuyu 5e).Ma Micrographs a gawo la mtanda wa chizindikiro chovala akuwonetsa kukhalapo kwa maenje ang'onoang'ono ozungulira ozunguliridwa ndi ma microcracks (mkuyu 5d), zomwe zingakhale chifukwa cha kupunduka kwakukulu kwa pulasitiki pafupi ndi pamwamba.The zinthu kusamutsa kwa zotayidwa okusayidi zigawo anali ochepa, pamene mabwalo anakhalabe (mkuyu. 5g).
M'lifupi ndi kuya kwa kuvala kwa zitsanzo kunawonjezeka ndi katundu wochuluka (pa 10 N), monga momwe tawonetsera pa mapu a pamwamba (mkuyu 6a).Abrasion ndi oxidation akadali njira zodzikongoletsera, ndipo kuwonjezeka kwa ma micro-scratches pamayendedwe ovala kumasonyeza kuti kuvala kwa magawo atatu kumapezekanso pa 10 N (Mkuyu 6b).Kusanthula kwa EDX kunawonetsa kupangidwa kwa zisumbu zachitsulo za oxide.The Al nsonga mu spectra anatsimikizira kuti kusamutsidwa kwa chinthu kuchokera mnzakeyo ku chitsanzo zinachitika pa 10 N (mkuyu 6c ndi Table 3), pamene izo sizinawonedwe pa 3 N (Table 2).Kuvala kwamagulu atatu kumayambitsidwa ndi tinthu tating'onoting'ono ta zisumbu za oxide ndi ma analogi, pomwe kusanthula kwatsatanetsatane kwa EDX kunavumbulutsa zonyamula kuchokera ku ma analogi (Supplementary Figure S3 ndi Table S1).Kukula kwa zilumba za oxide kumalumikizidwa ndi maenje akuya, omwe amawonedwanso mu 3N (mkuyu 5).Kusweka ndi kugawikana kwa carbides makamaka kumachitika mu carbides olemera mu 10 N Cr (Mkuyu 6e, f).Kuonjezera apo, ma carbides apamwamba a V amawombera ndi kuvala matrix ozungulira, omwe amachititsa kuti magawo atatu avale.Dzenje lofanana ndi kukula kwake ndi mawonekedwe a V carbide yapamwamba (yomwe ili mu bwalo lofiira) inawonekeranso pamtanda wa njanji (mkuyu 6d) (onani kukula kwa carbide ndi kusanthula mawonekedwe. 3.1), kusonyeza kuti V yapamwamba carbide V akhoza flake pa masanjidwewo pa 10 N. Maonekedwe ozungulira mkulu V carbides kumathandiza kukoka kwenikweni, pamene agglomerated mkulu Cr carbides sachedwa akulimbana (mkuyu. 6e, f).Khalidwe lolepherali likuwonetsa kuti masanjidwewo apitilira mphamvu yake yolimbana ndi kusinthika kwa pulasitiki komanso kuti ma microstructure samapereka mphamvu zokwanira zokhuza mphamvu pa 10 N. Kusweka kosunthika pansi pamadzi (mkuyu 6d) kukuwonetsa kulimba kwa mapindikidwe apulasitiki omwe amapezeka panthawi yotsetsereka.Pamene katundu akuwonjezeka pali kusamutsidwa kwa zinthu kuchokera ku njanji yovala kupita ku mpira wa alumina (mkuyu 6g), womwe ukhoza kukhala wokhazikika pa 10 N. Chifukwa chachikulu cha kuchepa kwa CoF values ​​​​(mkuyu 3).
Mbiri yapamtunda (a) ndi zithunzi (b-f) za topography yovala pamwamba (b-f) yazitsulo zosapanga dzimbiri za carbon martensitic zosapanga dzimbiri zomwe zimagwiritsidwa ntchito ndi EBA pa 10 N, kuvala ma track cross-section mu BSE mode (d) ndi ma microscope pamwamba. gawo la aluminiyamu pa 10 N (g).
Pamavalidwe otsetsereka, pamwamba pake pamakhala kupsinjika kwa antibody ndi kukameta ubweya, zomwe zimapangitsa kuti pakhale kupindika kwakukulu kwa pulasitiki pansi pa nthaka34,48,49.Chifukwa chake, kuumitsa ntchito kumatha kuchitika pansi pamtunda chifukwa cha kupunduka kwa pulasitiki, zomwe zimakhudza mavalidwe ndi njira zomwe zimatsimikizira kavalidwe ka chinthu.Choncho, mapu okhwima okhwima (monga momwe tafotokozera mu Gawo 2.4) adachitidwa mu phunziroli kuti adziwe chitukuko cha pulasitiki deformation zone (PDZ) pansi pa njira yovala ngati ntchito ya katundu.Popeza, monga tafotokozera m'zigawo zam'mbuyo, zizindikiro zomveka bwino za kusinthika kwa pulasitiki zinkawoneka pansi pa chovala (mkuyu 5d, 6d), makamaka pa 10 N.
Pa mkuyu.Chithunzi 7 chikuwonetsa zojambula zolimba zamtundu wa mavalidwe a HCMSS omwe amathandizidwa ndi ELP pa 3 N ndi 10 N. Ndizofunikira kudziwa kuti mfundo zowuma izi zidagwiritsidwa ntchito ngati cholozera kuwunika momwe ntchito imawumitsira.Kusintha kwa kuuma pansi pa chizindikiro cha kuvala kumachokera ku 667 kupita ku 672 HV pa 3 N (mkuyu 7a), kusonyeza kuti kuuma kwa ntchitoyo ndi kosafunika.Mwinamwake, chifukwa cha kutsika kwa mapu a microhardness (ie mtunda pakati pa zizindikiro), njira yoyezera kuuma kogwiritsidwa ntchito sikunathe kuzindikira kusintha kwa kuuma.M'malo mwake, madera a PDZ okhala ndi mphamvu zolimba kuchokera ku 677 mpaka 686 HV yokhala ndi kuya kwakukulu kwa 118 µm ndi kutalika kwa 488 µm adawonedwa pa 10 N (mkuyu 7b), yomwe imagwirizana ndi kukula kwa njira yovala ( Chithunzi 6a)).Deta yofananira pakukula kwa kukula kwa PDZ ndi katundu idapezeka mu kafukufuku wovala pa SS47 wothandizidwa ndi L-PBF.Zotsatira zikuwonetsa kuti kukhalapo kwa austenite yosungidwa kumakhudza ductility ya zitsulo zopangidwa mowonjezera 3, 12, 50, ndi kusungidwa kwa austenite kumasintha kukhala martensite panthawi yakusintha kwa pulasitiki (pulasitiki yakusintha kwa gawo), yomwe imathandizira kuuma kwachitsulo.zitsulo 51. Popeza chitsanzo cha VCMSS chili ndi austenite yosungidwa motsatira ndondomeko ya X-ray ya diffraction yomwe inakambidwa kale (mkuyu 2e), adanenedwa kuti kusungidwa kwa austenite mu microstructure kungasinthe kukhala martensite panthawi yolumikizana, potero kuonjezera kuuma kwa PDZ (mkuyu 2e). Chithunzi 7b).Kuphatikiza apo, mapangidwe a slip omwe amachitika panjira yovala (mkuyu 5e, 6f) akuwonetsanso kupunduka kwa pulasitiki komwe kumachitika chifukwa cha kutsetsereka kwa dislocation pansi pa kupsinjika kwa kukameta ubweya pakulumikizana kotsetsereka.Komabe, kumeta ubweya wa ubweya wopangidwa ndi 3 N sikunali kokwanira kuti apange kusungunuka kwakukulu kapena kusintha kwa kusungidwa kwa austenite ku martensite komwe kumawonedwa ndi njira yogwiritsidwa ntchito, kotero kuuma kwa ntchito kunawonedwa kokha pa 10 N (Mkuyu 7b).
Zithunzi za kuuma kwa magawo ang'onoang'ono a zitsulo zosapanga dzimbiri za carbon martensitic zoyendetsedwa ndi makina otulutsa magetsi pa 3 N (a) ndi 10 N (b).
Kafukufukuyu akuwonetsa machitidwe ovala ndi mawonekedwe a microstructural a chitsulo chatsopano cha carbon martensitic chosapanga dzimbiri chopangidwa ndi ELR.Mayesero ovala owuma anachitika potsetsereka pansi pa katundu wosiyanasiyana, ndipo zitsanzo zowonongeka zinayesedwa pogwiritsa ntchito ma electron microscopy, laser profilometer ndi mapu a kuuma kwa magawo a nyimbo zovala.
Kusanthula kwa Microstructural kunawonetsa kugawidwa kofanana kwa ma carbides okhala ndi chromium yambiri (~ 18.2% carbides) ndi vanadium (~ 4.3% carbides) mu matrix a martensite ndikusunga austenite yokhala ndi mphamvu yaying'ono kwambiri.Njira zazikulu zovalira ndizovala ndi makutidwe ndi okosijeni pakatundu wocheperako, pomwe kuvala kwa matupi atatu obwera chifukwa cha ma carbides otalikirapo a V ndi ma oxides otayirira ambewu kumathandiziranso kuvala pakuchulukira katundu.Mavalidwe ake ndiabwino kuposa L-PBF ndi zitsulo zosapanga dzimbiri zosapanga dzimbiri zamtundu wa austenitic, komanso zofananira ndi zitsulo zamakina a EBM zotsika kwambiri.Mtengo wa CoF umachepa ndi kuchuluka kwa katundu chifukwa cha kusamutsa zinthu kupita ku thupi lina.Pogwiritsa ntchito njira yopangira mapu okhwima, malo opindika a pulasitiki akuwonetsedwa pansipa.Kuwongolera kotheka kwa tirigu ndi kusintha kwa gawo mu matrix kumatha kufufuzidwanso pogwiritsa ntchito electron backscatter diffraction kuti mumvetsetse bwino zotsatira za kuumitsa ntchito.Kusintha kwapang'onopang'ono kwa mapu a microhardness sikulola kuwonetsetsa kwa kuuma kwa madera ovala pa katundu wochepa wogwiritsidwa ntchito, kotero nanoindentation ikhoza kupereka kusintha kwakukulu kwa kuuma pogwiritsa ntchito njira yomweyo.
Kafukufukuyu akupereka kwa nthawi yoyamba kusanthula kwatsatanetsatane kwa kukana kuvala komanso kukangana kwachitsulo chatsopano cha carbon martensitic chosapanga dzimbiri chopangidwa ndi ELR.Poganizira za ufulu wamapangidwe a geometric a AM komanso kuthekera kochepetsa masitepe opangira makina ndi AM, kafukufukuyu atha kuyambitsa njira yopangira zinthu zatsopanozi ndikugwiritsa ntchito pazida zokhudzana ndi kuvala kuchokera kumitengo kupita ku nkhungu za jakisoni wapulasitiki wokhala ndi njira yozizirira yovuta.
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