Carbide ndi gulu logwiritsidwa ntchito kwambiri la zida zogwirira ntchito mwachangu (HSM), zomwe zimapangidwa ndi njira zopangira zitsulo za ufa ndipo zimakhala ndi tinthu ta carbide yolimba (nthawi zambiri tungsten carbide WC) ndi kapangidwe kofewa kachitsulo. Pakadali pano, pali mazana a ma carbide opangidwa ndi simenti okhala ndi WC okhala ndi mitundu yosiyanasiyana, ambiri mwa iwo amagwiritsa ntchito cobalt (Co) ngati chomangira, nickel (Ni) ndi chromium (Cr) amagwiritsidwanso ntchito kwambiri ngati zinthu zomangira, ndipo ena amathanso kuwonjezeredwa. Nchifukwa chiyani pali mitundu yambiri ya carbide? Kodi opanga zida amasankha bwanji zida zoyenera pa ntchito inayake yodulira? Kuti tiyankhe mafunso awa, choyamba tiyeni tiwone zinthu zosiyanasiyana zomwe zimapangitsa kuti carbide yomangira ikhale chida choyenera.
kuuma ndi kulimba
Carbide yopangidwa ndi simenti ya WC-Co ili ndi ubwino wapadera pakulimba komanso kulimba. Tungsten carbide (WC) ndi yolimba kwambiri (yoposa corundum kapena alumina), ndipo kulimba kwake sikumachepa kawirikawiri pamene kutentha kwa ntchito kumakwera. Komabe, siili ndi kulimba kokwanira, chinthu chofunikira kwambiri pazida zodulira. Pofuna kugwiritsa ntchito kulimba kwakukulu kwa tungsten carbide ndikuwonjezera kulimba kwake, anthu amagwiritsa ntchito zomangira zachitsulo kuti agwirizanitse tungsten carbide, kotero kuti chipangizochi chili ndi kuuma kopitirira kuposa kwa chitsulo chothamanga kwambiri, pomwe chimatha kupirira mphamvu zambiri zodulira. Kuphatikiza apo, imatha kupirira kutentha kwakukulu kodulira komwe kumachitika chifukwa cha makina othamanga kwambiri.
Masiku ano, pafupifupi mipeni yonse ya WC-Co ndi zoyikapo zake zimakhala zophimbidwa, kotero ntchito ya maziko ake imaoneka yosafunika kwenikweni. Koma kwenikweni, ndi modulus yolimba kwambiri ya zinthu za WC-Co (muyeso wa kuuma, womwe ndi pafupifupi katatu kuposa chitsulo champhamvu kwambiri kutentha kwa chipinda) yomwe imapereka gawo losasinthika la chophimbacho. WC-Co matrix imaperekanso kulimba kofunikira. Zinthu izi ndi zinthu zoyambira za zinthu za WC-Co, koma zinthuzo zimatha kusinthidwa mwa kusintha kapangidwe ka zinthuzo ndi kapangidwe kake kakang'ono popanga ufa wa carbide wopangidwa ndi simenti. Chifukwa chake, kuyenerera kwa magwiridwe antchito a chida pamakina enaake kumadalira kwambiri njira yoyambira yopera.
Njira yopera
Ufa wa tungsten carbide umapezeka pogwiritsa ntchito ufa wa tungsten (W) wopangidwa ndi carburizing. Makhalidwe a ufa wa tungsten carbide (makamaka kukula kwa tinthu tating'onoting'ono) makamaka amadalira kukula kwa tinthu tating'onoting'ono ta ufa wa tungsten wosaphika komanso kutentha ndi nthawi ya carburizing. Kuwongolera mankhwala ndikofunikira kwambiri, ndipo kuchuluka kwa kaboni kuyenera kusungidwa kosasintha (pafupi ndi stoichiometric value ya 6.13% polemera). Kuchuluka pang'ono kwa vanadium ndi/kapena chromium kumatha kuwonjezedwa musanagwiritse ntchito carburizing kuti muwongolere kukula kwa tinthu tating'onoting'ono ta ufa kudzera munjira zotsatirazi. Mikhalidwe yosiyanasiyana ya njira yotsatizana ndi kugwiritsa ntchito komaliza komaliza kumafuna kuphatikiza kwapadera kwa kukula kwa tinthu ta tungsten carbide, kuchuluka kwa kaboni, kuchuluka kwa vanadium ndi kuchuluka kwa chromium, komwe mitundu yosiyanasiyana ya ufa wa tungsten carbide imatha kupangidwa. Mwachitsanzo, ATI Alldyne, kampani yopanga ufa wa tungsten carbide, imapanga mitundu 23 ya ufa wa tungsten carbide, ndipo mitundu ya ufa wa tungsten carbide womwe umasinthidwa malinga ndi zosowa za ogwiritsa ntchito imatha kufika kuwirikiza kasanu kuposa ufa wa tungsten carbide.
Posakaniza ndi kupukusa ufa wa tungsten carbide ndi chomangira chachitsulo kuti apange mtundu winawake wa ufa wa carbide wopangidwa ndi simenti, mitundu yosiyanasiyana ingagwiritsidwe ntchito. Kuchuluka kwa cobalt komwe kumagwiritsidwa ntchito kwambiri ndi 3% - 25% (chiŵerengero cha kulemera), ndipo ngati pakufunika kuwonjezera kukana kwa dzimbiri kwa chidacho, ndikofunikira kuwonjezera nickel ndi chromium. Kuphatikiza apo, chomangira chachitsulo chingawongoleredwenso powonjezera zigawo zina za alloy. Mwachitsanzo, kuwonjezera ruthenium ku WC-Co cemented carbide kungathandize kwambiri kulimba kwake popanda kuchepetsa kuuma kwake. Kuonjezera kuchuluka kwa chomangira kungathandizenso kulimba kwa carbide yopangidwa ndi simenti, koma kudzachepetsa kuuma kwake.
Kuchepetsa kukula kwa tinthu ta tungsten carbide kungapangitse kuti zinthuzo zikhale zolimba, koma kukula kwa tinthu ta tungsten carbide kuyenera kukhala komweko panthawi yothira. Panthawi yothira, tinthu ta tungsten carbide timasakanikirana ndikukula kudzera mu njira yosungunuka ndi kubwerezabwereza. Mu njira yeniyeni yothira, kuti apange chinthu cholimba kwambiri, chomangira chachitsulo chimakhala chamadzimadzi (chotchedwa liquid phase sintering). Kukula kwa tinthu ta tungsten carbide kumatha kulamulidwa powonjezera ma carbide ena osinthira achitsulo, kuphatikiza vanadium carbide (VC), chromium carbide (Cr3C2), titanium carbide (TiC), tantalum carbide (TaC), ndi niobium carbide (NbC). Ma carbide achitsulo awa nthawi zambiri amawonjezedwa pamene ufa wa tungsten carbide umasakanizidwa ndikuphwanyidwa ndi chomangira chachitsulo, ngakhale vanadium carbide ndi chromium carbide zimathanso kupangidwa pamene ufa wa tungsten carbide umayikidwa mu carburi.
Ufa wa tungsten carbide ungapangidwenso pogwiritsa ntchito zinthu zobwezerezedwanso za carbide zogwiritsidwanso ntchito. Kubwezeretsanso ndi kugwiritsanso ntchito kwa carbide yotsalira kwakhalapo kwa nthawi yayitali mumakampani opanga carbide yotsalira ndipo ndi gawo lofunikira kwambiri pa unyolo wonse wachuma wamakampaniwa, kuthandiza kuchepetsa ndalama zogulira zinthu, kusunga zachilengedwe ndikupewa zinyalala. Kutaya zinthu zoopsa. Carbide yotsalira ya simenti nthawi zambiri imatha kugwiritsidwanso ntchito pogwiritsa ntchito njira ya APT (ammonium paratungstate), njira yobwezeretsanso zinc kapena kuphwanya. Ufa wa tungsten carbide "wobwezerezedwanso" nthawi zambiri umakhala ndi kukhuthala kwabwino komanso kodziwikiratu chifukwa uli ndi malo ochepa kuposa ufa wa tungsten carbide wopangidwa mwachindunji kudzera mu njira ya tungsten carburizing.
Mikhalidwe yogwiritsira ntchito pogaya ufa wa tungsten carbide ndi chomangira chachitsulo ndi njira zofunika kwambiri zogaya. Njira ziwiri zomwe zimagwiritsidwa ntchito kwambiri pogaya ndi kugaya mpira ndi kugaya kwa micromilling. Njira zonsezi zimathandiza kusakaniza ufa wogaya ndi kukula kochepa kwa tinthu tating'onoting'ono. Kuti chomangira chomwe chasindikizidwa pambuyo pake chikhale ndi mphamvu zokwanira, kusunga mawonekedwe a chomangiracho, ndikulola wogwiritsa ntchito kapena woyendetsa kuti atenge chomangiracho kuti chigwiritsidwe ntchito, nthawi zambiri pamafunika kuwonjezera chomangira chachilengedwe panthawi yogaya. Kapangidwe ka mankhwala ka chomangirachi kangakhudze kuchuluka ndi mphamvu ya chomangiracho. Kuti zikhale zosavuta kugwira ntchito, ndibwino kuwonjezera zomangira zamphamvu kwambiri, koma izi zimapangitsa kuti chigangidwe chikhale chochepa ndipo zingayambitse ziphuphu zomwe zingayambitse zolakwika mu chinthu chomaliza.
Pambuyo pogaya, ufa nthawi zambiri umaumitsidwa ndi mankhwala opopera kuti apange ma agglomerate oyenda momasuka omwe amagwirizanitsidwa pamodzi ndi ma organic binder. Mwa kusintha kapangidwe ka organic binder, kuyenda bwino ndi kuchuluka kwa mphamvu ya ma agglomerate awa zitha kusinthidwa momwe mukufunira. Mwa kufufuza tinthu tating'onoting'ono kapena tating'onoting'ono, kufalikira kwa tinthu ta agglomerate kumatha kusinthidwanso kuti zitsimikizire kuyenda bwino akamayikidwa mu nkhungu.
Kupanga zinthu zogwirira ntchito
Ma workpiece a Carbide amatha kupangidwa pogwiritsa ntchito njira zosiyanasiyana. Kutengera kukula kwa workpiece, kuchuluka kwa mawonekedwe, ndi gulu lopangira, ma inserting ambiri odulidwa amapangidwa pogwiritsa ntchito ma dies olimba a pamwamba ndi pansi. Kuti pakhale kusinthasintha kwa kulemera kwa workpiece ndi kukula kwake nthawi iliyonse yokanikiza, ndikofunikira kuonetsetsa kuti kuchuluka kwa ufa (kulemera ndi kuchuluka) komwe kumalowa m'bowo kuli kofanana. Kutuluka kwa ufa kumayendetsedwa makamaka ndi kufalikira kwa kukula kwa ma agglomerates ndi mawonekedwe a organic binder. Ma workpiece opangidwa (kapena "malo opanda kanthu") amapangidwa pogwiritsa ntchito mphamvu ya molding ya 10-80 ksi (kilo mapaundi pa sikweya mita) ku ufa wodzazidwa mu bowo.
Ngakhale tinthu tating'onoting'ono tolimba ta tungsten carbide sitingasinthe kapena kusweka, koma chomangira chachilengedwe chimakanikizidwa m'mipata pakati pa tinthu ta tungsten carbide, motero chimakhazikitsa malo a tinthuto. Kupanikizika kukakhala kwakukulu, kumamatira kwa tinthu ta tungsten carbide kumalimba ndipo kuchuluka kwa chogwirira ntchito kumakulirakulira. Makhalidwe a utomoni wa ufa wa simenti wa carbide amatha kusiyana, kutengera zomwe zili mu chomangira chachitsulo, kukula ndi mawonekedwe a tinthu ta tungsten carbide, kuchuluka kwa agglomeration, komanso kapangidwe ndi kuwonjezera kwa chomangira chachilengedwe. Pofuna kupereka zambiri zokhudzana ndi momwe zimakhalira ndi utomoni wa ufa wa simenti wa carbide, ubale pakati pa kuchuluka kwa utomoni ndi kuthamanga kwa utomoni nthawi zambiri umapangidwa ndi wopanga ufa. Izi zimatsimikizira kuti ufa woperekedwa umagwirizana ndi njira yopangira zida.
Ma workpiece akuluakulu a carbide kapena ma workpiece a carbide okhala ndi ma aspect ratios apamwamba (monga ma shanks a ma end mills ndi ma drill) nthawi zambiri amapangidwa kuchokera ku carbide powder yosindikizidwa bwino mu thumba losinthasintha. Ngakhale kuti kupanga njira yosindikizira bwino kumakhala kotalika kuposa njira yopangira, mtengo wopanga chidacho ndi wotsika, kotero njira iyi ndi yoyenera kwambiri popanga zinthu zazing'ono.
Njira iyi ndi kuyika ufawo m'thumba, ndikutseka pakamwa pa thumba, kenako ndikuyika thumba lodzaza ndi ufa m'chipinda, ndikuyika mphamvu ya 30-60ksi kudzera mu chipangizo cha hydraulic kuti mukanikize. Ma workpiece okanikizidwa nthawi zambiri amapangidwa kuti agwirizane ndi geometries inayake asanayambe kupopera. Kukula kwa thumba kumakulitsidwa kuti kugwirizane ndi workpiece yocheperako panthawi yopopera komanso kupereka malire okwanira ogwiritsira ntchito popera. Popeza workpiece imafunika kukonzedwa mutakanikiza, zofunikira pakulipiritsa sizili zovuta monga momwe zimakhalira ndi njira yopangira, koma ndikofunikirabe kuonetsetsa kuti ufa womwewo umalowetsedwa m'thumba nthawi iliyonse. Ngati kuchuluka kwa kuchajidwa kwa ufa kuli kochepa kwambiri, kungayambitse kuti ufa usakwane m'thumba, zomwe zimapangitsa kuti workpiece ikhale yaying'ono kwambiri ndipo iyenera kuchotsedwa. Ngati kuchuluka kwa kunyamula kwa ufa kuli kwakukulu kwambiri, ndipo ufa wolowetsedwa m'thumba ndi wochuluka kwambiri, workpiece iyenera kukonzedwa kuti ichotse ufa wambiri ikakanizidwa. Ngakhale kuti ufa wochulukirapo womwe wachotsedwa ndi kuchotsedwa ukhoza kubwezeretsedwanso, kutero kumachepetsa kupanga.
Ma workpiece a Carbide amathanso kupangidwa pogwiritsa ntchito ma extrusion dies kapena ma injection dies. Njira yopangira ma extrusion ndiyoyenera kwambiri popanga ma workpiece a axisymmetric shape, pomwe njira yopangira ma injection nthawi zambiri imagwiritsidwa ntchito popanga ma workpiece ovuta. Mu njira zonse ziwiri zopangira ma unit, ma grade a carbide powder opangidwa ndi simenti amapachikidwa mu organic binder yomwe imapereka mawonekedwe ofanana ndi a toothpaste ku simenti ya carbide. Kenako composite imatulutsidwa kudzera mu dzenje kapena kulowetsedwa mu dzenje kuti ipangidwe. Makhalidwe a grade a carbide powder opangidwa ndi simenti amatsimikizira chiŵerengero chabwino cha ufa ndi binder mu chisakanizocho, ndipo amakhala ndi mphamvu yofunika pa kuyenda kwa chisakanizocho kudzera mu dzenje lotulukira kapena kulowetsedwa mu dzenje.
Pambuyo poti chogwirira ntchito chapangidwa ndi kuumba, kukanikiza kwa isostatic, kutulutsa kapena kuyika jekeseni, chogwirira chachilengedwe chiyenera kuchotsedwa pa chogwirira ntchito chisanafike gawo lomaliza la kuumba. Kuumba kumachotsa ma porosity kuchokera pa chogwirira ntchito, ndikupangitsa kuti chikhale chokhuthala kwambiri (kapena chokhuthala kwambiri). Panthawi youmba, chomangira chachitsulo chomwe chili mu chogwirira ntchito chopangidwa ndi press chimakhala chamadzimadzi, koma chogwirira ntchitocho chimasunga mawonekedwe ake pansi pa mphamvu za capillary ndi kulumikizana kwa tinthu tating'onoting'ono.
Pambuyo pochotsa chotsukira, mawonekedwe a chotsukira amakhalabe omwewo, koma miyeso yake imachepetsedwa. Kuti mupeze kukula kofunikira kwa chotsukira pambuyo pochotsa chotsukira, kuchuluka kwa chotsukira kuyenera kuganiziridwa popanga chidacho. Mlingo wa ufa wa carbide womwe umagwiritsidwa ntchito popanga chida chilichonse uyenera kupangidwa kuti ukhale ndi chotsukira choyenera ukaphwanyidwa pansi pa mphamvu yoyenera.
Pafupifupi nthawi zonse, chithandizo cha sintered workpiece chimafunika pambuyo powaza. Chithandizo chachikulu cha zida zodulira ndi kunola m'mphepete mwa chodulira. Zida zambiri zimafuna kupukutidwa kwa mawonekedwe ndi kukula kwake pambuyo powaza. Zida zina zimafuna kupukutidwa pamwamba ndi pansi; zina zimafuna kupukutidwa kwa mbali zina (ndi kapena popanda kunola m'mphepete mwa chodulira). Zidutswa zonse za carbide kuchokera ku chodulira zimatha kubwezeretsedwanso.
Chophimba cha ntchito
Nthawi zambiri, chogwirira ntchito chomalizidwacho chimayenera kuphimbidwa. Chophimbacho chimapereka mafuta ndi kuuma kowonjezereka, komanso chotchinga chofalikira ku chogwirira ntchito, kuteteza okosijeni ikakumana ndi kutentha kwambiri. Chogwirira cha carbide chopangidwa ndi simenti ndichofunikira kwambiri pakugwira ntchito kwa chogwiriracho. Kuphatikiza pa kusintha makhalidwe akuluakulu a ufa wa matrix, makhalidwe apamwamba a matrix amathanso kusinthidwa mwa kusankha mankhwala ndikusintha njira yoyeretsera. Kudzera mu kusamuka kwa cobalt, cobalt yochulukirapo imatha kuwonjezeredwa mu gawo lakunja la tsamba mkati mwa makulidwe a 20-30 μm poyerekeza ndi gawo lonse la chogwirira ntchito, motero kupatsa pamwamba pa chogwirira ntchito mphamvu ndi kulimba bwino, zomwe zimapangitsa kuti chikhale cholimba kwambiri ku kusintha.
Kutengera njira yawo yopangira (monga njira yochotsera dewaxing, kutentha, nthawi yochotsa sintering, kutentha ndi mphamvu ya carburizing), wopanga zida akhoza kukhala ndi zofunikira zapadera pa mtundu wa ufa wa carbide wopangidwa ndi simenti womwe umagwiritsidwa ntchito. Opanga zida ena amatha kupukuta workpiece mu uvuni wa vacuum, pomwe ena angagwiritse ntchito ng'anjo yotentha ya isostatic pressing (HIP) (yomwe imakakamiza workpiece kumapeto kwa ndondomekoyi kuti achotse zotsalira zilizonse). Ma workpiece opangidwa mu uvuni wa vacuum angafunikenso kukakamizidwa ndi kutentha kwambiri kudzera mu njira yowonjezera kuti awonjezere kuchuluka kwa workpiece. Opanga zida ena angagwiritse ntchito kutentha kwakukulu kwa vacuum kuti awonjezere kuchuluka kwa sintered kwa zosakaniza zokhala ndi cobalt yochepa, koma njira iyi ikhoza kukulitsa kapangidwe kake. Kuti asunge kukula kwa tirigu wabwino, ufa wokhala ndi tinthu tating'onoting'ono ta tungsten carbide ukhoza kusankhidwa. Kuti agwirizane ndi zida zinazake zopangira, mikhalidwe ya dewaxing ndi mphamvu ya carburizing zimakhalanso ndi zofunikira zosiyana za kuchuluka kwa kaboni mu ufa wa carbide wopangidwa ndi simenti.
Kugawa magiredi
Kusintha kwa mitundu yosiyanasiyana ya ufa wa tungsten carbide, kapangidwe kake kosakanikirana ndi kuchuluka kwa chomangira chachitsulo, mtundu ndi kuchuluka kwa choletsa kukula kwa tirigu, ndi zina zotero, zimapangitsa mitundu yosiyanasiyana ya ma carbide opangidwa ndi simenti. Izi zimatsimikizira kapangidwe kake kakang'ono ka carbide yopangidwa ndi simenti ndi mawonekedwe ake. Kuphatikiza kwina kwa makhalidwe kwakhala kofunikira kwambiri pa ntchito zina zapadera zokonzera, zomwe zimapangitsa kuti zikhale zomveka kugawa mitundu yosiyanasiyana ya ma carbide opangidwa ndi simenti.
Machitidwe awiri omwe amagwiritsidwa ntchito kwambiri pogawa ma carbide pa ntchito zopanga makina ndi C designation system ndi ISO designation system. Ngakhale kuti palibe dongosolo lililonse lomwe limasonyeza bwino zinthu zomwe zimakhudza kusankha ma carbide grade opangidwa ndi simenti, amapereka poyambira kukambirana. Pa gulu lililonse, opanga ambiri ali ndi ma carbide awoawo apadera, zomwe zimapangitsa kuti pakhale mitundu yosiyanasiyana ya ma carbide grade.
Magulu a Carbide amathanso kugawidwa m'magulu malinga ndi kapangidwe kake. Magulu a Tungsten carbide (WC) amatha kugawidwa m'magulu atatu oyambira: osavuta, a microcrystalline ndi alloyed. Magulu a Simplex amakhala makamaka ndi tungsten carbide ndi cobalt binders, koma amathanso kukhala ndi zoletsa kukula kwa tirigu. Magulu a microcrystalline amapangidwa ndi tungsten carbide ndi cobalt binder yowonjezeredwa ndi vanadium carbide (VC) ndi (kapena) chromium carbide (Cr3C2), ndipo kukula kwake kwa tirigu kumatha kufika 1 μm kapena kuchepera. Magulu a alloy amapangidwa ndi tungsten carbide ndi cobalt binders okhala ndi titanium carbide (TiC) yochepa, tantalum carbide (TaC), ndi niobium carbide (NbC). Zowonjezera izi zimadziwikanso kuti cubic carbides chifukwa cha mphamvu zawo zowononga. Kapangidwe ka microcrystal kamene kamakhala ndi kapangidwe kosagwirizana ka magawo atatu.
1) Mitundu yosavuta ya carbide
Ma grade awa odulira zitsulo nthawi zambiri amakhala ndi cobalt 3% mpaka 12% (potengera kulemera). Kukula kwa tinthu ta tungsten carbide nthawi zambiri kumakhala pakati pa 1-8 μm. Monga momwe zilili ndi ma grade ena, kuchepetsa kukula kwa tinthu ta tungsten carbide kumawonjezera kuuma kwake ndi mphamvu yodulira yopingasa (TRS), koma kumachepetsa kulimba kwake. Kuuma kwa mtundu woyera nthawi zambiri kumakhala pakati pa HRA89-93.5; mphamvu yodulira yopingasa nthawi zambiri imakhala pakati pa 175-350ksi. Ufa wa ma grade awa ukhoza kukhala ndi zinthu zambiri zobwezerezedwanso.
Magiredi osavuta amatha kugawidwa m'magulu a C1-C4 mu dongosolo la C grade, ndipo amatha kugawidwa m'magulu malinga ndi mndandanda wa magiredi a K, N, S ndi H mu dongosolo la ISO grade. Magiredi a Simplex okhala ndi makhalidwe apakati amatha kugawidwa m'magulu azinthu zonse (monga C2 kapena K20) ndipo angagwiritsidwe ntchito potembenuza, kugaya, kupala ndi kupotoza; magiredi okhala ndi tirigu wochepa kapena cobalt wochepa komanso kuuma kwakukulu amatha kugawidwa m'magulu otsiriza (monga C4 kapena K01); magiredi okhala ndi tirigu wokulirapo kapena cobalt wochuluka komanso kulimba bwino amatha kugawidwa m'magulu a roughing (monga C1 kapena K30).
Zipangizo zopangidwa mu Simplex grade zingagwiritsidwe ntchito popanga chitsulo chopangidwa ndi chitsulo chosapanga dzimbiri cha 200 ndi 300, aluminiyamu ndi zitsulo zina zopanda chitsulo, ma superalloy ndi zitsulo zolimba. Ma grade amenewa angagwiritsidwenso ntchito popanga zinthu zopanda chitsulo (monga miyala ndi zida zobowola za geological), ndipo ma grade amenewa ali ndi kukula kwa tirigu wa 1.5-10μm (kapena kuposerapo) ndi kuchuluka kwa cobalt wa 6%-16%. Kugwiritsa ntchito kwina kopanda chitsulo kwa ma grade osavuta a carbide ndiko kupanga ma dies ndi punches. Ma grade amenewa nthawi zambiri amakhala ndi kukula kwa tirigu wapakati wokhala ndi cobalt wa 16%-30%.
(2) Mitundu ya kabodidi yopangidwa ndi simenti ya microcrystalline
Ma grade otere nthawi zambiri amakhala ndi 6%-15% ya cobalt. Pa nthawi ya madzi oundana, kuwonjezera vanadium carbide ndi/kapena chromium carbide kumatha kuwongolera kukula kwa tirigu kuti apange kapangidwe ka tirigu wosalala wokhala ndi tinthu tating'onoting'ono tosakwana 1 μm. Grade iyi yokhala ndi tinthu tating'onoting'ono imakhala ndi kuuma kwakukulu komanso mphamvu zodumphadumpha zopitilira 500ksi. Kuphatikiza kwa mphamvu yayikulu komanso kulimba kokwanira kumalola ma grade awa kugwiritsa ntchito ngodya yayikulu ya rake, yomwe imachepetsa mphamvu zodulira ndikupanga zidutswa zopyapyala podula m'malo mokakamiza zinthu zachitsulo.
Kudzera mu kuzindikira bwino zinthu zosiyanasiyana zopangira popanga ufa wa carbide wopangidwa ndi simenti, komanso kuwongolera bwino momwe zinthu zimayendera kuti zisapangike tirigu wokulirapo kwambiri m'kapangidwe kake, n'zotheka kupeza zinthu zoyenera. Kuti tisunge kukula kwa tirigu kukhala kochepa komanso kofanana, ufa wobwezerezedwanso uyenera kugwiritsidwa ntchito pokhapokha ngati pali ulamuliro wonse wa zinthu zopangira ndi njira yobwezeretsera, komanso kuyesa kwambiri khalidwe.
Magiredi a microcrystalline amatha kugawidwa malinga ndi mndandanda wa giredi M mu dongosolo la giredi la ISO. Kuphatikiza apo, njira zina zogawa mu dongosolo la giredi C ndi dongosolo la giredi la ISO ndizofanana ndi magiredi oyera. Magiredi a microcrystalline angagwiritsidwe ntchito kupanga zida zodula zinthu zofewa zogwirira ntchito, chifukwa pamwamba pa chidacho pakhoza kupangidwa ndi makina osalala kwambiri ndipo kumatha kukhala ndi m'mphepete wakuthwa kwambiri.
Ma grade a microcrystalline angagwiritsidwenso ntchito popanga ma superalloy okhala ndi nickel, chifukwa amatha kupirira kutentha kotentha mpaka 1200°C. Pokonza ma superalloy ndi zipangizo zina zapadera, kugwiritsa ntchito zida za microcrystalline grade ndi zida za pure grade zomwe zili ndi ruthenium nthawi imodzi kungathandize kukana kutopa, kukana kusintha kwa masinthidwe komanso kulimba. Ma grade a microcrystalline ndi oyeneranso kupanga zida zozungulira monga ma drill omwe amapanga kupsinjika kwa shear. Pali drill yopangidwa ndi ma grade a composite a carbide yopangidwa ndi simenti. M'magawo enaake a drill yomweyo, kuchuluka kwa cobalt muzinthuzo kumasiyana, kotero kuti kuuma ndi kulimba kwa drill kumakonzedwa bwino malinga ndi zosowa zokonzera.
(3) Mitundu ya carbide yopangidwa ndi simenti ya alloy
Magulu amenewa amagwiritsidwa ntchito makamaka podula zigawo zachitsulo, ndipo kuchuluka kwa cobalt komwe kumakhalapo nthawi zambiri kumakhala 5%-10%, ndipo kukula kwa tinthu tating'onoting'ono kumakhala pakati pa 0.8-2μm. Mwa kuwonjezera 4%-25% titanium carbide (TiC), chizolowezi cha tungsten carbide (WC) chofalikira pamwamba pa chitsulo chingachepe. Mphamvu ya chida, kukana kutayika kwa crater ndi kukana kutentha kungawongoleredwe powonjezera mpaka 25% tantalum carbide (TaC) ndi niobium carbide (NbC). Kuwonjezera ma cubic carbide otere kumawonjezeranso kuuma kofiira kwa chida, zomwe zimathandiza kupewa kusintha kwa kutentha kwa chidacho pakudula kwambiri kapena ntchito zina komwe m'mphepete mwake mupanga kutentha kwambiri. Kuphatikiza apo, titanium carbide imatha kupereka malo a nucleation panthawi yowotcha, ndikuwonjezera kufanana kwa kugawa kwa cubic carbide mu workpiece.
Kawirikawiri, kuuma kwa ma carbide opangidwa ndi simenti ya alloy ndi HRA91-94, ndipo mphamvu ya kusweka kwa transverse ndi 150-300ksi. Poyerekeza ndi ma grade oyera, ma alloy ali ndi kukana koipa kwa kuvala komanso mphamvu zochepa, koma ali ndi kukana bwino kwa zomatira. Ma grade a alloy amatha kugawidwa mu C5-C8 mu dongosolo la C grade, ndipo amatha kugawidwa malinga ndi mndandanda wa ma grade a P ndi M mu dongosolo la ISO grade. Ma grade a alloy okhala ndi makhalidwe apakati amatha kugawidwa ngati ma grade ofunikira (monga C6 kapena P30) ndipo angagwiritsidwe ntchito potembenuza, kugogoda, kupala ndi kugaya. Ma grade ovuta kwambiri amatha kugawidwa ngati ma grade omaliza (monga C8 ndi P01) pomaliza kutembenuza ndi ntchito zotopetsa. Ma grade awa nthawi zambiri amakhala ndi kukula kochepa kwa tirigu komanso kuchuluka kwa cobalt kochepa kuti apeze kuuma kofunikira komanso kukana kwa kuvala. Komabe, zinthu zofanana zimatha kupezeka powonjezera ma cubic carbides ambiri. Ma grade okhala ndi kulimba kwambiri amatha kugawidwa ngati ma roughing grade (monga C5 kapena P50). Ma grade amenewa nthawi zambiri amakhala ndi tinthu tating'onoting'ono tating'onoting'ono komanso cobalt yambiri, yokhala ndi ma cubic carbide ochepa kuti akwaniritse kulimba komwe kukufunika mwa kuletsa kukula kwa ming'alu. Pa ntchito zozungulira zomwe zasokonezedwa, magwiridwe antchito odulira amatha kuwonjezeredwa pogwiritsa ntchito ma grade olemera a cobalt omwe atchulidwa pamwambapa okhala ndi cobalt yambiri pamwamba pa chida.
Ma alloy grade okhala ndi titanium carbide yotsika amagwiritsidwa ntchito popanga zitsulo zosapanga dzimbiri ndi chitsulo chofewa, komanso angagwiritsidwe ntchito popanga zitsulo zopanda chitsulo monga ma superalloy okhala ndi nickel. Kukula kwa tinthu tating'onoting'ono timeneti nthawi zambiri kumakhala kochepera 1 μm, ndipo kuchuluka kwa cobalt ndi 8%-12%. Ma grade olimba, monga M10, angagwiritsidwe ntchito popanga chitsulo chofewa; ma grade olimba, monga M40, angagwiritsidwe ntchito popanga chitsulo chofewa ndi chofewa, kapena kupanga chitsulo chosapanga dzimbiri kapena ma superalloy.
Ma carbide opangidwa ndi simenti a alloy angagwiritsidwenso ntchito popanga zinthu zosagwiritsa ntchito chitsulo, makamaka popanga zinthu zosagwiritsidwa ntchito. Kukula kwa tinthu tating'onoting'ono ta ma grade amenewa nthawi zambiri kumakhala 1.2-2 μm, ndipo kuchuluka kwa cobalt ndi 7%-10%. Popanga ma grade amenewa, nthawi zambiri amawonjezedwa zinthu zambiri zobwezerezedwanso, zomwe zimapangitsa kuti pakhale ndalama zambiri zogwiritsira ntchito zida zogwiritsidwa ntchito. Ziwalo zogwiritsidwa ntchito zimafuna kukana dzimbiri komanso kuuma kwambiri, zomwe zingapezeke powonjezera nickel ndi chromium carbide popanga ma grade amenewa.
Pofuna kukwaniritsa zofunikira zaukadaulo komanso zachuma za opanga zida, ufa wa carbide ndiye chinthu chofunikira kwambiri. Ufa wopangidwira zida zopangira makina ndi magawo a njira za opanga zida umatsimikizira kugwira ntchito kwa ntchito yomalizidwa ndipo wapangitsa kuti pakhale mitundu yambiri ya carbide. Kapangidwe ka zinthu za carbide zomwe zimabwezerezedwanso komanso kuthekera kogwira ntchito mwachindunji ndi ogulitsa ufa zimathandiza opanga zida kuwongolera bwino mtundu wa zinthu zawo komanso mtengo wa zinthuzo.
Nthawi yotumizira: Okutobala-18-2022
