Kusakaniza kwa Superalloys
(1) Makhalidwe a Brazing ma superalloy amatha kugawidwa m'magulu atatu: maziko a nickel, maziko achitsulo ndi maziko a cobalt. Ali ndi mphamvu zabwino zamakaniko, kukana okosijeni komanso kukana dzimbiri kutentha kwambiri. Aloyi wa maziko a nickel ndiye amene amagwiritsidwa ntchito kwambiri popanga zinthu zogwira ntchito.
Superalloy ili ndi Cr2O3 oxide yambiri, ndipo filimu ya Cr2O3 oxide yomwe ndi yovuta kuchotsa imapangidwa pamwamba panthawi yotenthetsera. Ma superalloy a nickel base ali ndi Al ndi Ti, omwe ndi osavuta kusungunuka akatenthedwa. Chifukwa chake, kupewa kapena kuchepetsa kusungunuka kwa ma superalloy panthawi yotenthetsera ndikuchotsa filimu ya oxide ndiye vuto lalikulu panthawi yotenthetsera. Popeza borax kapena boric acid mu flux ingayambitse dzimbiri la chitsulo choyambira pa kutentha kwa brazing, boron yomwe imatuluka pambuyo pa reaction imatha kulowa mu chitsulo choyambira, zomwe zimapangitsa kuti granular infiltration ilowe. Pa ma nickel base alloys okhala ndi Al ndi Ti yambiri, vacuum degree mu mkhalidwe wotentha siyenera kukhala yochepera 10-2 ~ 10-3pa panthawi yotenthetsera kuti apewe kusungunuka pamwamba pa alloy panthawi yotenthetsera.
Kuti zitsulo zomangira zitsulo zikhale zolimba komanso zouma, kutentha kwa zitsulo zomangira zitsulo kuyenera kukhala kofanana ndi kutentha kwa zitsulo zomangira zitsulo kuti zitsimikizire kuti zitsulo zomangira zitsulozo zasungunuka bwino. Kutentha kwa zitsulo zomangira zitsulo kumakhala kochepa kwambiri, ndipo zitsulo zomangira zitsulo sizingasungunuke kwathunthu; Ngati kutentha kwa zitsulo zomangira zitsulo kuli kokwera kwambiri, ndipo zinthuzo sizingakonzedwenso ngakhale zitatenthedwa. Kutentha kwa zitsulo zomangira zitsulo zolimba kumakhala kokwera kwambiri, zomwe nthawi zambiri sizingakhudze zinthuzo chifukwa cha kutentha kwambiri kwa zitsulo zomangira zitsulo.
Ma superalloy ena a nickel base, makamaka ma alloy olimbikitsidwa ndi mvula, amakhala ndi chizolowezi chosweka. Asanayambe kusweka, kupsinjika komwe kumachitika panthawiyi kuyenera kuchotsedwa kwathunthu, ndipo kupsinjika kwa kutentha kuyenera kuchepetsedwa panthawi yosweka.
(2) Brazing material nickel base alloy ikhoza kupangidwa ndi siliva, mkuwa woyera, nickel base ndi active solder. Ngati kutentha kwa cholumikizira sikuli kokwera, zinthu zopangidwa ndi siliva zingagwiritsidwe ntchito. Pali mitundu yambiri ya siliva. Pofuna kuchepetsa kupsinjika kwamkati panthawi yotenthetsera brazing, ndibwino kusankha solder yokhala ndi kutentha kochepa kosungunuka. Fb101 flux ingagwiritsidwe ntchito brazing ndi siliva base filler metal. Fb102 flux imagwiritsidwa ntchito brazing precipitation strengthen superalloy yokhala ndi aluminiyamu yambiri, ndipo 10% ~ 20% sodium silicate kapena aluminium flux (monga fb201) imawonjezedwa. Pamene kutentha kwa brazing kupitirira 900 ℃, fb105 flux iyenera kusankhidwa.
Mukayika chitsulo mu vacuum kapena mumlengalenga woteteza, mkuwa weniweni ungagwiritsidwe ntchito ngati chitsulo chodzaza chitsulo. Kutentha kwa chitsulo ndi 1100 ~ 1150 ℃, ndipo cholumikiziracho sichidzapanga ming'alu yopsinjika, koma kutentha kogwira ntchito sikuyenera kupitirira 400 ℃.
Chitsulo chodzaza cha nickel base brazing ndi chomwe chimagwiritsidwa ntchito kwambiri mu Superalloys chifukwa cha kutentha kwake kwabwino komanso palibe kusweka kwa nkhawa panthawi yopangira brazing. Zinthu zazikulu zomwe zili mu nickel base solder ndi Cr, Si, B, ndipo solder yaying'ono imakhala ndi Fe, W, ndi zina zotero. Poyerekeza ndi ni-cr-si-b, b-ni68crwb brazing filler metal imatha kuchepetsa kulowa kwa B mu chitsulo choyambira ndikuwonjezera kutentha komwe kumasungunuka. Ndi chitsulo chodzaza cha brazing cha zida zogwirira ntchito zotentha kwambiri komanso masamba a turbine. Komabe, kusinthasintha kwa solder yokhala ndi W kumawonjezeka ndipo kusiyana kwa malo olumikizirana kumakhala kovuta kuwongolera.
Chitsulo chodzaza ma diffusion brazing sichili ndi chinthu cha Si ndipo chili ndi kukana kwabwino kwa okosijeni ndi vulcanization. Kutentha kwa brazing kumatha kusankhidwa kuyambira 1150 ℃ mpaka 1218 ℃ malinga ndi mtundu wa solder. Pambuyo pa brazing, cholumikizira cha brazing chokhala ndi mawonekedwe ofanana ndi chitsulo choyambira chingapezeke pambuyo pa 1066 ℃ diffusion treatment.
(3) Brazing process nickel base alloy imatha kugwiritsa ntchito brazing mu ng'anjo yoteteza mpweya, vacuum brazing ndi transient liquid phase connection. Musana brazing, pamwamba pake payenera kuchotsedwa mafuta ndikuchotsedwa ndi sandpaper polishing, felt wheel polishing, acetone scrubbing ndi kuyeretsa mankhwala. Mukasankha magawo a brazing process, ziyenera kudziwika kuti kutentha kwa kutentha sikuyenera kukhala kwakukulu kwambiri ndipo nthawi yoti brazing ikhale yochepa kuti tipewe mphamvu yamphamvu ya mankhwala pakati pa flux ndi base metal. Pofuna kupewa base metal kuti isasweke, zigawo zozizira zomwe zakonzedwa ziyenera kuchepetsedwa kupsinjika musanaziwotchere, ndipo welding heating iyenera kukhala yofanana momwe zingathere. Pa ma superalloys olimba a mvula, zigawozo ziyenera kuthandizidwa kaye ndi yankho lolimba, kenako kuziwotcherera pa kutentha kokwera pang'ono kuposa kuchiritsa kukalamba, ndipo potsiriza kuchiza kukalamba.
1) Kuyika chitsulo mu ng'anjo yoteteza Kuyika chitsulo mu ng'anjo yoteteza kumafuna mpweya woteteza kwambiri. Pa ma superalloys okhala ndi w (AL) ndi w (TI) osakwana 0.5%, mame ayenera kukhala otsika kuposa -54 ℃ pamene hydrogen kapena argon zikugwiritsidwa ntchito. Pamene kuchuluka kwa Al ndi Ti kukuwonjezeka, pamwamba pa alloy kumakhuthalabe ikatenthedwa. Njira zotsatirazi ziyenera kutengedwa: Onjezani flux pang'ono (monga fb105) ndikuchotsa filimu ya oxide ndi flux; 0.025 ~ 0.038mm wandiweyani wokutidwa pamwamba pa ziwalo zina; Thirani solder pamwamba pa zinthu zomwe ziyenera kuyikidwa chitsulo pasadakhale; Onjezani flux pang'ono ya gasi, monga boron trifluoride.
2) Kuphimba kwa vacuum brazing Kuphimba kwa vacuum brazing kumagwiritsidwa ntchito kwambiri kuti pakhale chitetezo chabwino komanso ubwino wa kuphimba. Onani tebulo 15 kuti mudziwe momwe makina amagwirira ntchito polumikizira ma superalloy a nickel base. Pa ma superalloy okhala ndi w (AL) ndi w (TI) osakwana 4%, ndi bwino kuyika electroplate wosanjikiza wa 0.01 ~ 0.015mm nickel pamwamba, ngakhale kuti kunyowetsa kwa solder kungatsimikizidwe popanda chithandizo chapadera. Pamene w (AL) ndi w (TI) zikupitirira 4%, makulidwe a nickel covering ayenera kukhala 0.020.03mm. Kuphimba kopyapyala kwambiri sikuteteza, ndipo kuphimba kopyapyala kwambiri kumachepetsa mphamvu ya cholumikizira. Zigawo zomwe ziyenera kulumikizidwa zitha kuyikidwanso m'bokosi kuti zigwirizane ndi vacuum brazing. Bokosilo liyenera kudzazidwa ndi getter. Mwachitsanzo, Zr imayamwa mpweya pa kutentha kwakukulu, komwe kumatha kupanga vacuum yapafupi m'bokosi, motero kuletsa kusungunuka kwa pamwamba pa alloy.
Gome 15 kagwiritsidwe ntchito ka makina a Vacuum Brazed Joints a superalloys wamba wa nickel base
Kapangidwe kake ndi mphamvu ya cholumikizira cha Superalloy zimasintha ndi cholumikizira cha brazing, ndipo chithandizo cha kufalikira pambuyo pa brazing chidzawonjezeranso mtengo wovomerezeka wa cholumikizira. Potengera Inconel alloy mwachitsanzo, kusiyana kwakukulu kwa cholumikizira cha Inconel cholumikizidwa ndi b-ni82crsib kumatha kufika 90um pambuyo pa chithandizo cha kufalikira pa 1000 ℃ kwa 1H; Komabe, pa zolumikizira zolumikizidwa ndi b-ni71crsib, kusiyana kwakukulu ndi pafupifupi 50um pambuyo pa chithandizo cha kufalikira pa 1000 ℃ kwa 1H.
3) Kulumikizana kwa gawo lamadzimadzi kwa nthawi yochepa Kulumikizana kwa gawo lamadzimadzi kwa nthawi yochepa kumagwiritsa ntchito alloy yolumikizana (pafupifupi 2.5 ~ 100um makulidwe) yomwe malo ake osungunuka ndi otsika kuposa chitsulo choyambira ngati chitsulo chodzaza. Pansi pa kupanikizika pang'ono (0 ~ 0.007mpa) ndi kutentha koyenera (1100 ~ 1250 ℃), zinthu zolumikizana zimasungunuka koyamba ndikunyowetsa chitsulo choyambira. Chifukwa cha kufalikira mwachangu kwa zinthu, kulimba kwa isothermal kumachitika pa cholumikizira kuti apange cholumikizira. Njirayi imachepetsa kwambiri zofunikira zofanana za pamwamba pa chitsulo choyambira ndikuchepetsa kuthamanga kwa welding. Magawo akuluakulu a kulumikizana kwa gawo lamadzimadzi kwa nthawi yochepa ndi kuthamanga, kutentha, nthawi yogwira komanso kapangidwe ka cholumikizira. Ikani kupanikizika kochepa kuti pamwamba pa weldment pakhale bwino. Kutentha ndi nthawi yotenthetsera zimakhudza kwambiri magwiridwe antchito a cholumikizira. Ngati cholumikiziracho chikufunika kukhala cholimba ngati chitsulo choyambira ndipo sichikhudza magwiridwe antchito a chitsulo choyambira, magawo a njira yolumikizira kutentha kwambiri (monga ≥ 1150 ℃) ndi nthawi yayitali (monga 8 ~ 24h) ayenera kuvomerezedwa; Ngati mtundu wa cholumikiziracho wachepetsedwa kapena chitsulo choyambira sichingathe kupirira kutentha kwakukulu, kutentha kochepa (1100 ~ 1150 ℃) ndi nthawi yochepa (1 ~ 8h) ziyenera kugwiritsidwa ntchito. Gawo lapakati liyenera kutenga kapangidwe ka chitsulo cholumikizidwa ngati kapangidwe koyambira, ndikuwonjezera zinthu zosiyanasiyana zoziziritsira, monga B, Si, Mn, Nb, ndi zina zotero. Mwachitsanzo, kapangidwe ka Udimet alloy ndi ni-15cr-18.5co-4.3al-3.3ti-5mo, ndipo kapangidwe ka gawo lapakati la kulumikizana kwa gawo lamadzimadzi ndi b-ni62.5cr15co15mo5b2.5. Zinthu zonsezi zimatha kuchepetsa kutentha kwa Ni Cr kapena Ni Cr Co alloys mpaka kufika pamlingo wotsika kwambiri, koma zotsatira za B ndizodziwikiratu kwambiri. Kuphatikiza apo, kuchuluka kwa B komwe kumafalikira kumatha kusintha mwachangu alloy yolumikizana ndi chitsulo choyambira.
Nthawi yotumizira: Juni-13-2022