Mefuta ea ts’ebetso ea kalafo ea mocheso oa liliba tse kholo tse nang le mochini o thata oa maqhubu

Liliba tse bophara bo boholo li entsoe ka likhoele tse chesang. Joaloka liliba tsa li-valve tse kholo, li tlameha ho mamella bolelele le khatello ka makhetlo a mangata nakong ea ts’ebetso. Ka hona, ba lokela ho ba le elasticity e ntle le matla a mokhathala. Mekhoa ea ho hloleha ea selemo ke mokhathala o robehileng le khatello ea maikutlo, ‘me liliba tse ka bang 90% lia hloleha ka lebaka la ho robeha ha mokhathala. Ho latela maemo a ts’ebeletso ea eona, tšepe ea selemo ea 50CrVA e nang le ho thatafala hantle, ho senyeha hanyane le thepa e ntle ea mochini ho tlameha ho khethoa. Kamora ho tima + mocheso o mahareng o futhumatsang ka mochini o thata oa maqhubu a phahameng, e ka fihlela litlhoko tsa eona tsa mosebetsi ka botlalo. Kajeno, ke tla u joetsa ka ts’ebetso ea kalafo e futhumatsang ea maqhubu a phahameng.

(1) Ts’ebetso ea kalafo ea mocheso

a. Nako ea selemo pele e thelisoa e entsoe ka lisebelisoa tse khorisang, ‘me ho futhumatsa ha selemo ho etsoa ke mochini o thatafatsang maqhubu a phahameng. E na le litšobotsi tsa nako e khuts’oane ea ho futhumatsa le lithollo tse ntle tsa austenite. Ka lebaka la lithollo tse ntle tsa austenite, ‘mele oa thepa oa eketseha. Palo ea lithollo tsa sebopeho le sebaka sa meeli ea lijo-thollo li fokotsa khatello ea maikutlo le ho eketsa ho hanyetsoa ha ts’ebetso ea ts’ebetso. Mocheso o futhumatsang ke (900 ± 10) ℃. Ka nako ena, lintho tse bonahalang tse phahameng mocheso matla le plasticity ntle li sebelisetsoa ho etsa phikolosetsa bonolo. Leha ho le joalo, mocheso o futhumatsang ha oa lokela ho ba o phahameng haholo kapa nako ea ho ts’oara e telele haholo, ho seng joalo thepa e tla chesa kapa e koahele Oxidation le decarburization e kanna ea fella ka ho phethoha le ho petsoha.

b. Ho tima + tempering ka mocheso o mahareng. Ho futhumatsa ho etsoa mochini o thatafatsang maqhubu a phahameng, mocheso oa ho futhumatsa ke 850-880 ℃, coefficient e bolokang mocheso e baloa ho 1.5min / mm, ho ipapisitse le ho thunya, setsi se futhumatsang se na le tšusumetso ea bohlokoa ho thatafalo le ts’ebetso ea selemo, ‘me ho futhumatsa oli ho ka khethoa. Kopana le litlhoko tsa ts’ebetso ea eona.

c. Tempering e boetse e etsoa ke mochini o tima maqhubu a phahameng haholo. Ho latela litlhoko tsa ho thatafala, ho shebahala hantle le lekhalo, sebelisa sesebelisoa se ikhethileng se futhumatsang ho se lokisa le ho se beha ka nepo. Mocheso o futhumatsang ke 400-440 ℃, ‘me metsi a pholile kamora ho boloka mocheso. Mocheso o futhumetseng oa liliba tse akaretsang hangata ke 400-500 ℃, ‘me matla a phahameng a mokhathala a ka fumanoa kamora ho halefa.

(2) Tlhahlobo le lintlha tsa ts’ebetsong tsa ts’ebetso ea kalafo ea mocheso ea selemo

Hobane tšepe ea 50CrVA e na le likarolo tse ngata tse kopantsoeng, ho thatafala ha tšepe ho ntlafalitsoe. Chromium ke karolo e matla ea carbide, ‘me carbides ea tsona e teng pela moeli oa lijo-thollo, ka hona e ka thibela kholo ea lithollo, ka hona e ntlafalitsoe ka nepo mocheso o tima’ me ho lelefatsa nako ea ho e ts’oara ho ke ke ha baka kholo ea lithollo tsa kristale.

Nakong ea ho futhumatsa ha liliba tsa coil e chesang, tlhokomelo e lokela ho lefuoa kamanong e pakeng tsa decarburization le ho tima mocheso oa ho futhumatsa le nako. Tloaelo e bontšitse hore mocheso o phahameng o tima le nako e telele ea ho futhumatsa li tla baka hore decarburization e eketsehe. Ka hona, ha mochini o tima maqhubu a phahameng o sebelisetsoa ho futhumatsa, mekhahlelo ea ts’ebetso e lokela ho laoloa ka thata. Ntle le moo, ho roala kapa ho paka ho futhumatsa ho futhumatsa ho ka sebelisoa ho fokotsa ho kenella le ho theola bokaholimo. Ho na le lingoliloeng tse reng ho hlaka hoa metsi nakong ea selemo ho fokotsa bophelo ba ts’ebeletso, mme ho bonolo ho ba sesosa sa mapetso a mokhathala.

Mocheso o mofuthu oa selemo nakong ea selemo ke ho fumana sebopeho le ts’ebetso ea ts’ebetso e hlokahalang. Ha re nahana hore tšepe ea 50CrVA ke sesebelisoa se hlahisang brittleness ea bobeli, e tlameha ho qhibiliha kapele (ho futhumatsa ha oli kapa metsi) kamora ho halefa ho thibela bohale bo hlabang (ho baka ho thatafala ha eona ho fokotsehile), mme e ka baka khatello ea masalla e salletseng holimo, e leng molemo ho ntlafatsa matla a mokhathala. Hangata, ho sebelisoa ho pholisa metsi ho fapana le ho futhumatsa ha oli. Sebopeho kamora ho halefa ke terostite e nang le boima ba 40-46HRC. E na le elasticity e ntle le matla a lekaneng le ho thatafala. Ntle le moo, haeba nako ea tempering e le khuts’oane haholo, sebopeho le ts’ebetso e ts’oanang ha li fumanehe, mme ts’ebetso ha e ntlafatsoe haeba nako e le telele haholo. Ka hona, tlhahlobo ea ts’ebetso e lokela ho etsoa ho fumana nako e loketseng.