1. Zipangizo zomangira
(1) Zitsulo zomangira zitsulo ndi ma carbide opangidwa ndi simenti nthawi zambiri amagwiritsa ntchito zitsulo zomangira zitsulo zamkuwa, zinc zamkuwa ndi siliva. Mkuwa woyera umakhala ndi mphamvu yonyowa bwino ku mitundu yonse ya ma carbide opangidwa ndi simenti, koma zotsatira zabwino kwambiri zitha kupezeka pomanga zitsulo mumlengalenga wochepetsa wa haidrojeni. Nthawi yomweyo, chifukwa cha kutentha kwakukulu kwa brazing, kupsinjika kwa cholumikizira kumakhala kwakukulu, zomwe zimapangitsa kuti ming'alu ikule. Mphamvu yodula ya cholumikizira chomangiriridwa ndi mkuwa woyera ndi pafupifupi 150MPa, ndipo pulasitiki yolumikizira nayonso ndi yayikulu, koma siyoyenera ntchito yotentha kwambiri.
Chitsulo chodzaza zinc cha mkuwa ndicho chomwe chimagwiritsidwa ntchito kwambiri pa zitsulo zomangira ndi ma carbide opangidwa ndi simenti. Pofuna kuonjezera kunyowa kwa solder ndi mphamvu ya cholumikizira, Mn, Ni, Fe ndi zinthu zina za alloy nthawi zambiri zimawonjezeredwa ku solder. Mwachitsanzo, w (MN) 4% imawonjezeredwa ku b-cu58znmn kuti mphamvu yometa ya zolumikizira zomangira za simenti ya carbide yomangira ifike 300 ~ 320MPa kutentha kwa chipinda; Imathabe kusunga 220 ~ 240mpa pa 320 ℃. Kuwonjezera CO pang'ono pamaziko a b-cu58znmn kungapangitse mphamvu yometa ya cholumikizira chomangira ifike 350Mpa, ndipo imakhala ndi mphamvu yayikulu komanso mphamvu yotopa, zomwe zimapangitsa kuti zida zodulira ndi zida zobowola miyala zigwire ntchito bwino.
Malo otsika osungunuka a chitsulo chodzaza mkuwa wa siliva komanso kutentha pang'ono kwa cholumikizira cholumikizidwa ndi kothandiza kuchepetsa kusweka kwa carbide yolumikizidwa ndi simenti panthawi ya cholumikizira. Pofuna kupititsa patsogolo kunyowa kwa cholumikizira ndikuwonjezera mphamvu ndi kutentha kwa cholumikizira, Mn, Ni ndi zinthu zina za alloy nthawi zambiri zimawonjezeredwa ku cholumikizira. Mwachitsanzo, cholumikizira cha b-ag50cuzncdni chili ndi kunyowa kwabwino kwambiri ku carbide yolumikizidwa ndi simenti, ndipo cholumikizira cholumikizidwa chili ndi mawonekedwe abwino.
Kuwonjezera pa mitundu itatu ya zitsulo zodzaza brazing zomwe zili pamwambapa, zitsulo zodzaza brazing zochokera ku Mn ndi Ni, monga b-mn50nicucrco ndi b-ni75crsib, zitha kusankhidwa kuti zigwiritsidwe ntchito pa carbide yolimba yoposa 500 ℃ ndipo zimafuna mphamvu yayikulu yolumikizirana. Pazitsulo zolimbitsa chitsulo chothamanga kwambiri, chitsulo chapadera chodzaza brazing chokhala ndi kutentha kofanana ndi kutentha kozimitsa chiyenera kusankhidwa. Chitsulo chodzaza ichi chimagawidwa m'magulu awiri: chimodzi ndi chitsulo chodzaza cha mtundu wa ferromanganese, chomwe chimapangidwa makamaka ndi ferromanganese ndi borax. Mphamvu yometa ya cholumikizira chometa nthawi zambiri imakhala pafupifupi 100MPa, koma cholumikiziracho chimakhala ndi ming'alu; Mtundu wina wa aloyi wapadera wamkuwa wokhala ndi Ni, Fe, Mn ndi Si si wosavuta kupanga ming'alu m'malo olumikizira brazing, ndipo mphamvu yake yometa imatha kuwonjezeka kufika pa 300mpa.
(2) Kusankha kwa brazing flux ndi shielding gas brazing flux kuyenera kugwirizana ndi chitsulo choyambira ndi chitsulo chodzaza chomwe chiyenera kulumikizidwa. Pa brazing tool steel ndi simenti carbide, brazing flux yomwe imagwiritsidwa ntchito makamaka ndi borax ndi boric acid, ndipo ma fluoride ena (KF, NaF, CaF2, ndi zina zotero) amawonjezedwa. Fb301, fb302 ndi fb105 fluxes amagwiritsidwa ntchito popangira copper zinc solder, ndipo fb101 ~ fb104 fluxes amagwiritsidwa ntchito popangira silver copper solder. Borax flux imagwiritsidwa ntchito makamaka pamene special brazing filler metal imagwiritsidwa ntchito popangira high speed steel.
Pofuna kupewa kukhuthala kwa chitsulo cha zida panthawi yotenthetsera brazing komanso kupewa kuyeretsa pambuyo pa brazing, brazing yotetezedwa ndi gasi ingagwiritsidwe ntchito. Mpweya woteteza ukhoza kukhala mpweya wosagwira ntchito kapena mpweya wochepetsa, ndipo mame a gasi ayenera kukhala otsika kuposa -40 ℃ Carbide yopangidwa ndi simenti ikhoza kutsukidwa pansi pa chitetezo cha haidrojeni, ndipo mame a haidrojeni omwe amafunikira ayenera kukhala otsika kuposa -59 ℃.
2. Ukadaulo wa brazing
Chitsulo cha zida chiyenera kutsukidwa musanagwiritse ntchito brazing, ndipo pamwamba pake sipayenera kukhala posalala kwambiri kuti zinthu zinyowe ndi kufalikira bwino komanso kuti brazing flux zisamanyowe. Pamwamba pa carbide yopangidwa ndi simenti iyenera kuphwanyidwa mchenga musanagwiritse ntchito brazing, kapena kupukutidwa ndi silicon carbide kapena diamond grinding wheel kuti ichotse carbon yochuluka pamwamba pake, kuti inyowe ndi brazing filler metal panthawi yogwiritsira ntchito brazing. Carbide yopangidwa ndi simenti yokhala ndi titanium carbide ndi yovuta kunyowetsa. Copper oxide kapena nickel oxide phala imayikidwa pamwamba pake mwanjira yatsopano ndikuphikidwa mumlengalenga wochepetsera kuti mkuwa kapena nickel isinthe pamwamba pake, kuti solder yamphamvu ikhale yonyowa.
Kupaka zitsulo za kaboni kuyenera kuchitika nthawi isanayambe kapena nthawi yomweyo ndi nthawi yozimitsa. Ngati kupaka zitsulo kukuchitika nthawi isanayambe kuzimitsa, kutentha kwa solidus kwa chitsulo chodzaza chomwe chikugwiritsidwa ntchito kuyenera kukhala kokwera kuposa kutentha kozimitsa, kotero kuti weldment ikadali ndi mphamvu zokwanira ikatenthedwanso kutentha kozimitsa popanda kulephera. Pamene kuyika zitsulo ndi kuzimitsa ziphatikizidwa, chitsulo chodzaza chomwe chili ndi kutentha kwa solidus pafupi ndi kutentha kozimitsa chiyenera kusankhidwa.
Chitsulo cha zida za alloy chili ndi zigawo zambiri. Chitsulo choyenera chodzaza brazing, njira yochizira kutentha ndi ukadaulo wophatikiza brazing ndi njira yochizira kutentha ziyenera kutsimikiziridwa malinga ndi mtundu wa chitsulocho, kuti pakhale magwiridwe antchito abwino olumikizirana.
Kutentha kwa chitsulo chothamanga kwambiri nthawi zambiri kumakhala kokwera kuposa kutentha kwa siliva copper ndi copper zinc solder, kotero ndikofunikira kuzimitsa musanazimitse ndi kuzimitsa panthawi yotenthetsera yachiwiri kapena itatha. Ngati kuzimitsa kukufunika pambuyo pa kuzimitsa, chitsulo chapadera chodzaza brazing chokhacho chingagwiritsidwe ntchito pozimitsa. Mukazimitsa zida zodulira chitsulo chothamanga kwambiri, ndikoyenera kugwiritsa ntchito ng'anjo ya coke. Chitsulo chodzaza brazing chikasungunuka, chotsani chida chodulira ndikuchikanikiza nthawi yomweyo, tulutsani chitsulo chowonjezera chodzaza brazing, kenako chizimitseni mafuta, kenako chizimitseni pa 550 ~ 570 ℃.
Mukayika tsamba la carbide lopangidwa ndi simenti ndi chida chachitsulo, njira yowonjezera mpata wa brazing ndikugwiritsa ntchito gasket yolipirira pulasitiki mu mpata wa brazing iyenera kutsatiridwa, ndipo kuziziritsa pang'onopang'ono kuyenera kuchitika mutagwiritsa ntchito welding kuti muchepetse kupsinjika kwa brazing, kupewa ming'alu ndikuwonjezera moyo wa ntchito ya chida cha carbide chopangidwa ndi simenti.
Pambuyo polumikiza ulusi, zotsalira za flux pa weldment ziyenera kutsukidwa ndi madzi otentha kapena kusakaniza kochotsa slag, kenako kuzisakaniza ndi njira yoyenera yochotsera oxide film pa base tool rod. Komabe, samalani kuti musagwiritse ntchito nitric acid solution kuti mupewe dzimbiri la brazing joint metal.
Nthawi yotumizira: Juni-13-2022