Anthu ambiri akamamva 'martensitic stainless steel', nthawi yomweyo amaganiza 'zolimba'. Izi sizolakwika, koma ndiye poyambira kusamvetsetsana kwakukulu pakugula ndi kugwiritsa ntchito. Nkhani yeniyeni sikungokhudza kupeza nambala yapamwamba ya Rockwell C; ndi za kuvina kovutirapo pakati pa chemistry, chithandizo cha kutentha, ndi kusinthanitsa kosalephereka. Ndawonapo ma projekiti ambiri akuyimitsidwa chifukwa wina adatchula generic 410 kapena 420 ya 'kukana dzimbiri ndi mphamvu' osamvetsetsa zomwe zimafunikira pashopu. Ming'alu yozimitsa, kuwombana kozungulira pambuyo pouma, kusowa kodabwitsa kwa kulimba kwa chinthu chomwe chimawoneka ngati chigawo cholimba - awa ndi maphunziro enieni. Izi sizinthu zamabuku; ndi zomwe mumaphunzira mutachotsa magulu angapo.
Chidziwitso Chachikulu ndi Zotsatira Zake Zothandiza
Tiyeni tivule. Martensitic chitsulo chosapanga dzimbiri kwenikweni ndi aloyi yolimba ya Fe-Cr-C. Mfungulo yake ndiyo kusinthika kwa martensitic—kuzimitsidwa kofulumira kwa kutentha kosasunthika kumene kumatchera maatomu a carbon, kupanga chokhotakhota, chodzaza kwambiri ndi thupi lomwe lili ndi mbali zinayi zapakati pa thupi. Ndimo gwero la kuuma. Koma nachi chinthu choyamba chogwira ntchito: mukamakwera kaboni wakuuma (monga mu 440C), m'pamene mumasokoneza kwambiri kutenthedwa, komanso mosagwirizana ndi chitsulo chosapanga dzimbiri, kukana dzimbiri. Chromium iyenera kugwirizana ndi kaboni kuti ipange ma carbides, omwe amachotsa yankho, kuchepetsa chromium yaulere yomwe imapezeka kuti ipange wosanjikiza wa oxide passive. Chifukwa chake, mutha kukhala ndi tsamba lolimba la 58 HRC lomwe likuwonetsabe madontho a dzimbiri.
Mu ntchito yathu yomanga pa Malingaliro a kampani Qingdao Qiangsenyuan Technology Co., Ltd., nthawi zambiri timakumana ndi zinthu ziwiri izi. Wofuna chithandizo adzatumiza chojambula cha chigawo cha vavu kapena shaft ya mpope mu 17-4PH (mtundu wa mvula-woumitsa martensitic, koma tiyeni tiwupange apa kuti tikambirane). Amafuna mphamvu ya maginito, mphamvu zokolola, komanso kukana kwa dzimbiri. Vutoli limayambira pazida zopangira. Kupsyinjika komwe kumapangidwa ndi bar stock kuchokera pakupangira kwake kumatha kuwononga nthawi yathu yotsatira CNC makina. Taphunzira nthawi zonse kutchula katundu wochepetsera kupsinjika pamiyeso yovuta kwambiri, kapena bajeti yamankhwala apakati tokha. Ndi mtengo, koma ndiotsika mtengo kuposa gawo lomwe limazungulira 0.1mm mutatha kutentha komaliza.
Kuchiza kutentha komweko ndiko kumene luso limakumana ndi sayansi. Sikuti 'set ndi kuiwala' ng'anjo pulogalamu. Kutentha kozizira kwambiri ndi kofunikira—kutsika kwambiri, ndipo simupeza yankho lathunthu; okwera kwambiri, mumayika pachiwopsezo chosunga austenite kapena kukula kwambewu. Ndiye kuzimitsa: mafuta ndi muyezo, koma mukubwadamuka ndi kutentha kwa mafuta quenchant nkhani kwambiri pofuna kuchepetsa kupotoza ndi ang'onoang'ono chiwopsezo, makamaka pa zovuta castings ndalama ndi osiyanasiyana mtanda magawo. Poyamba tinali ndi mipanda yopyapyala kuponya ndalama ma prototypes mu 410 amasweka pafupifupi momveka panthawi yozimitsa. Kodi tikuphunzirapo chiyani? Pamawonekedwe odabwitsa, nthawi zina giredi ya martensitic si yankho, kapena kapangidwe kake kamafunika ma radii ndi makulidwe a yunifolomu omwe tingatsutse pagawo la DFM (Design for Manufacture).
Machining ndi Kumaliza: The Shop Floor Reality
Machining achotsedwa martensitic zitsulo zosapanga dzimbiri ndi chilombo chosiyana ndi kukonza mawonekedwe ake ouma. M'malo ocheperako (nthawi zambiri amachitikira pafupifupi 85 HRB), ndizovuta. Simaswa tchipisi bwinobwino ngati 303 austenitic; imakonda kupanga tchipisi tating'ono tazingwe zomwe zimatha kuwotcherera ku chida ndikuwononga kumapeto. Zida za geometry, zokutira (TiAlN imagwira ntchito bwino), komanso zoziziritsa kukhosi zothyoka ndikutulutsa tchipisi sizingakambirane. Timagwira ntchito izi pazovuta zathu, zolimba CNC makina malo kuti zichepetse kugwedera.
Chithandizo cha kutentha kwa post-machining ndichosabwereranso. Mukaumitsa, kukonza kwina kulikonse kumakhala kovuta kwambiri, kumangokhalira kugaya kapena EDM. Kutsatizanaku ndikofunika kwambiri. Tinali ndi zokumana nazo zowawa za kuphunzira zaka zapitazo ndi gawo la zida. Wogula ankafuna kudulidwa mano ataumitsa kuti atsimikizire kuti geometry yabwino. Tidayenera kuchita mgwirizano ndi katswiri wokhala ndi mawilo akupera a CBN, ndipo mtengo ndi kuchulukira kwa nthawi kunali kofunikira. Tsopano, machitidwe athu wamba, ndi zomwe timalangiza makasitomala papulatifomu yathu tsngtaocnc.com, ndikuyika makina omaliza mu gawo lokhazikika, kuwerengera kukula kodziwikiratu/kuchepa kuchokera pakuumitsa ndi kutenthetsa. Izi zimafuna laibulale yakuzama ya mbiri yakale ya momwe ma geometrium amasunthira, zomwe tapanga zaka 30 kupopera ndi makina.
Kumaliza ndi nuance ina. A passivated martensitic zitsulo zosapanga dzimbiri gawo silikhala ndi kukana kwa dzimbiri kwa gawo la 316L. Njira yochepetsera (nthawi zambiri nitric kapena citric acid) imathandiza, koma imapangitsa kuti chigawo chofooka chikhale chochepa. Pazogwiritsidwa ntchito m'malo owononga pang'ono, monga zida zina zamakina opangira chakudya kapena zida zam'madzi, ma electropolish apamwamba kwambiri pambuyo podutsa amatha kupanga kusiyana kowonekera. Imafewetsa nsonga zazing'ono, kuchepetsa malo oyambira poyambira. Ndi sitepe yowonjezera, koma imatseka kusiyana pakati pa kuchepa kwa zinthu ndi zofunikira pakugwiritsa ntchito.
Kusankha Zinthu: Nthawi Yogwiritsa Ntchito, Nthawi Yoyenda
Ichi ndiye maziko a kuweruza kwa akatswiri. Martensitic chitsulo chosapanga dzimbiri imawala pomwe mukufunikira kuphatikiza kukana kwa dzimbiri, kulimba kwakukulu / kuuma, ndipo nthawi zambiri, kutha kwa maginito. Ganizirani ma turbine m'malo ena a nthunzi, zodulira, mpeni, zida zopangira opaleshoni, mipikisano yothamangira m'malo osamira pansi pamadzi, ndi zomangira ngati mabawuti amphamvu kwambiri. Mitundu yowumitsa mvula ngati 17-4PH ndi yabwino kwambiri pazinthu zovuta, zamphamvu kwambiri zakuthambo zomwe zimayenera kupirira zolimba pambuyo pochiza kukalamba kocheperako.
Komabe, muyenera kuzipewa pazomanga zomangika bwino (kupatulapo njira zochizira kutentha kwambiri kapena kutentha kwambiri), popaka malo okhala ndi chloride (monga pafupi ndi madzi a m'nyanja opanda chitetezo), kapena komwe kulimba kwa kutentha kumakhala kofunika kwambiri. Mapangidwe apakati pa thupi la martensite ali ndi kutentha kwa kusintha kwa ductile-to-brittle; ikhoza kukhala yowopsa kwambiri pakutumikira kozizira. Ndikukumbukira kulephera kusanthula ndodo yosweka ya hydraulic piston yomwe imagwiritsidwa ntchito pamakina akunja ankhalango m'nyengo yozizira; zinthu za 420 zidakumana ndi kuuma kwake koma zidasweka pakukhudzidwa. Austenitic chosapanga dzimbiri kapena chitsulo chotsika kutentha chikanakhala cholondola.
Kugwira ntchito ndi ma aloyi apadera monga cobalt-based kapena nickel-based alloys nthawi zina amapereka njira yabwino kwambiri, ngakhale pamtengo wapamwamba. Mwachitsanzo, pa chopopera chopopera choyaka kwambiri komanso chowononga pang'ono, cholumikizira cholimba cha martensitic chosapanga dzimbiri chonga 440C chingaganizidwe, koma chowotcherera chowotcherera cha Stellite (cobalt alloy) kapena cholimba. kuponya ndalama mu aloyi wa nickel ngati Alloy 255 atha kupereka mtengo wapamwamba wozungulira moyo ngakhale pamtengo wapamwamba kwambiri. Ku QSY, nthawi zambiri timakhala ndi zokambiranazi, kuwongolera makasitomala kudzera mu magwiridwe antchito, kupanga, ndi mtengo wonse.
Case in Point: A Valve Component Saga
Chitsanzo cha konkire kuchokera ku shopu yathu. Wofuna chithandizo amafunikira tsinde la valve yothamanga kwambiri. Chofunikiracho chinafuna kukana kwabwino kwa dzimbiri ndi mankhwala ocheperako, kukana kuvala kwambiri pamalo osindikizira, komanso kusasinthika kosatha pansi pa kupsinjika kwa 900 MPa. Poyamba adaganiza zokhala ndi 316L kuti ipewe dzimbiri. Tinakankhira kumbuyo. 316L sakanaumitsidwa mokwanira kuti avale. Tidapanga 440C kuti ikhale pamwamba pake koma tidayang'anizana ndi kusiyana kwa kukana kwa dzimbiri.
Yankho lake linali njira yosakanizidwa. Thupi lalikulu la tsinde lidapangidwa kuchokera ku 17-4PH mu Condition A (annealed), kenako okalamba mpaka H900 atapanga makina, ndikuwapatsa mphamvu yayikulu. Malo ovuta kwambiri osindikizira adawumitsidwa pamalopo pogwiritsa ntchito njira ya laser kuti apange malo olimba a martensitic popanda kuwononga dzimbiri zazinthu zambiri. Inali njira yosavomerezeka yomwe inkafuna mgwirizano wapamtima pakati pathu makina gulu ndi wothandizira kutentha kutentha. Gawolo linapambana, koma chotengera chinali choyera martensitic zitsulo zosapanga dzimbiri silinali yankho layekha; inali gawo la njira yopangira zinthu.
Kuthetsa mavuto kwamtunduwu ndikomwe ma sheet azinthu zamtundu uliwonse amasowa. Amakupatsani mphamvu zokolola komanso kuchuluka kwa dzimbiri mu asidi wa labotale, koma samakuwuzani momwe zinthuzo zimakhalira mukamayesa kulekerera kulekerera kwa 0.02mm pa flange yopyapyala yomwe iwona kuzimitsa kwa 800 ° C. Chidziwitso chimenecho chimabwera chifukwa chochita, kulephera nthawi zina, ndi kubwerezabwereza. Ichi ndichifukwa chake makampani omwe ali ndi mbiri yayitali mu kupopera ndi makina, mofanana ndi yathu ya zaka zoposa makumi atatu, sonkhanitsani mtundu wa chidziwitso chachinsinsi chomwe chili chamtengo wapatali ngati makina omwe ali pansi.
Malingaliro Omaliza: Lemekezani Njira
Ndiye, mawu omaliza ndi chiyani martensitic zitsulo zosapanga dzimbiri? Ndi banja lamphamvu, losinthasintha, koma limafunikira ulemu. Sikuti 'dontho-in' m'malo mwa chitsulo cha carbon mukafuna kukana dzimbiri. Makhalidwe ake amagwirizana kwambiri ndi mbiri yake yotentha. Kuyifotokoza bwino kumafuna kulingalira mozama za njira yonse yopangira - kuchokera momwe mphero imagwirira ntchito kapena kapangidwe kake. chipolopolo nkhungu kuponyera, kupyolera mu makina onse opangira makina, molunjika mu ng'anjo yotentha ndikupita ku benchi yomaliza yoyendera.
Cholakwika chachikulu ndikuchitenga ngati chinthu. Ndizinthu zogwira ntchito kwambiri zomwe zimafuna njira yoyendetsera ntchito. Mukachikonza bwino, zotsatira zake zimakhala zapadera: zigawo zomwe zimakhala zolimba, zolimba, komanso zoyenera kuchita. Mukalakwitsa, zolephera zimakhala zodula komanso zophunzitsa. Cholinga ndikukweza choyambirira ndikuchepetsa chomaliza, chomwe pamapeto pake, ndiye gwero la uinjiniya wothandiza ndi chilichonse, makamaka chovuta komanso chopindulitsa ngati chosapanga dzimbiri la martensitic.
