Kukho iindlela ezininzi eziqhelekileyo ezisetyenziswayo zonyango lobushushu kwi-ductile iron.
Kwisakhiwo se-iron ductile, i-graphite i-spherical, kwaye impembelelo yayo ebuthakathaka kunye neyonzakalisayo kwi-matrix ibuthathaka kune-flake graphite. Ukusebenza kwe-iron ductile ikakhulu kuxhomekeke kwisakhiwo se-matrix, kwaye impembelelo yegraphite yeyesibini. Ukuphucula ubume be-matrix ye-iron ductile ngokusebenzisa unyango oluhlukeneyo lobushushu kunokuphucula iimpawu zayo zomatshini ukuya kumaqondo ahlukeneyo. Ngenxa yempembelelo yokwakheka kweekhemikhali, izinga lokupholisa, i-agent ye-spheroidizing kunye nezinye izinto, isakhiwo esixubileyo se-ferrite + pearlite + cementite + graphite sihlala sibonakala kwisakhiwo se-as-cast, ngakumbi kudonga oluncinci lokuphosa. Injongo yonyango lokushisa kukufumana isakhiwo esifunekayo kwaye ngaloo ndlela kuphuculwe iimpawu zomatshini.
Iindlela zokunyanga ukushisa ezisetyenziswa ngokuqhelekileyo kwi-ductile iron zezi zilandelayo.
(1) Ubushushu obuphantsi graphitization annealing ubushushu bobushushu 720 ~ 760 ℃. Ipholiswa kwiziko ukuya ngaphantsi kwe-500 ℃ kwaye emva koko ipholiswe ngomoya. Ukubola i-eutectoid cementite ukufumana isinyithi se-ductile kunye ne-ferrite matrix ukuphucula ukuqina.
(2) Ubushushu obuphezulu be-graphitization annealing kwi-880 ~ 930 ℃, emva koko idluliselwe kwi-720 ~ 760 ℃ yokugcina ubushushu, kwaye emva koko ipholiswe ngesithando somlilo ukuya ngaphantsi kwe-500 ℃ kunye nomoya opholileyo ngaphandle kwesithando somlilo. Ukuphelisa isakhiwo esimhlophe kwaye ufumane isinyithi se-ductile kunye ne-ferrite matrix, ephucula iplastiki, inciphisa ubunzima kunye nokwandisa ukuqina.
(3) Gqibezela i-austenitization kunye nesiqhelo kwi-880 ~ 930 ℃, indlela yokupholisa: ukupholisa inkungu, ukupholisa umoya okanye ukupholisa umoya. Ukunciphisa uxinzelelo, yongeza inkqubo yokuthoba: 500 ~ 600 ℃ ukufumana i-pearlite + encinci ye-ferrite + imilo engqukuva yeGrafite, eyandisa amandla, ubulukhuni kunye nokumelana nokunxiba.
(4) I-austenitization engaphelelanga, ukulinganisa kunye nokufudumeza kwi-820 ~ 860 ℃, indlela yokupholisa: ukupholisa inkungu, ukupholisa umoya okanye ukupholisa umoya. Ukuze unciphise uxinzelelo, yongeza inkqubo yokufudumala: i-500 ~ 600 ℃ ukufumana i-pearlite + encinci yentsimbi ehlakaziweyo Isakhiwo somzimba sifezekisa iipropati ezingcono ezibanzi zoomatshini.
(5) Ukucima kunye nokunyangwa kokunyanga: ukufudumeza kwi-840 ~ 880 ° C, indlela yokupholisa: ioli okanye ukupholisa amanzi, ukufudumala kweqondo lokushisa emva kokucima: 550 ~ 600 ° C, ukufumana isakhiwo se-sorbite esiphundu kunye nokuphucula iimpawu zomatshini ezibanzi.
(6) Ukucima i-Isothermal: Ukufudumala kwi-840 ~ 880 ℃ kunye nokucima kwindawo yokuhlambela ityuwa kwi-250 ~ 350 ℃ ukufumana iipropati ezibanzi zoomatshini, ngakumbi ukuphucula amandla, ukuqina kunye nokumelana nokunxiba.
Ngexesha lonyango lobushushu kunye nokufudumeza, iqondo lobushushu lokugalela ukungena eziko ngokuqhelekileyo lingaphantsi kwe-350 ° C. Isantya sokufudumeza sixhomekeke kubukhulu kunye nobunzima bokuphosa, kwaye ikhethwe phakathi kwe-30 ~ 120 ° C / h. Ubushushu bokungena kwesithando somlilo kwiindawo ezinkulu kunye neziyinkimbinkimbi kufuneka zibe ngaphantsi kwaye izinga lokufudumeza kufuneka libe lincinci. Ubushushu bokufudumala buxhomekeke kwisakhiwo se-matrix kunye nokwakhiwa kweekhemikhali. Ixesha lokubamba lixhomekeke kubukhulu bodonga lokuphosa.
Ukongeza, i-ductile iron castings inokucinywa ngaphezulu kusetyenziswa i-frequency ephezulu, i-medium frequency, ilangatye kunye nezinye iindlela zokufumana ubunzima obuphezulu, ukumelana nokunxiba kunye nokumelana nokudinwa. Isenokunyangwa nge-nitriding ethambileyo ukuphucula ukuxhathisa kokunxiba kwe-castings.
I-1.Ukucima kunye nokunyanga unyango lwe-ductile iron
IiDuctile castings zifuna ubulukhuni obuphezulu njengeebheringi, kwaye iinxalenye zentsimbi zihlala zicinywa kwaye zinomsindo kumaqondo aphantsi. Inkqubo: ukufudumeza ukuphosa kwiqondo lokushisa kwe-860-900 ° C, ukuyikhusela ukuvumela yonke i-matrix yokuqala ukuba i-austenitize, emva koko ipholise kwi-oyile okanye ityuwa etyhidiweyo ukufezekisa ukucima, kwaye emva koko ishushu kwaye igcinwe kwi-250-350. °C yokufudumala, kwaye i-matrix yokuqala iguqulelwa kwi-martensite yoMlilo kunye nesakhiwo esigciniweyo se-austenite, ubume boqobo obungqukuva begraphite buhlala bungatshintshi. I-castings ephathwayo inobulukhuni obuphezulu kunye nokuqina okuthile, igcina iimpawu zokuthambisa zegraphite, kwaye ziphucule ukuxhathisa ukunxiba.
Ukuphoswa kwentsimbi, njengamalungu e-shaft, njengee-crankshafts kunye neerodi zokuqhagamshela iinjini ze-diesel, zifuna iimpawu ezibanzi zoomatshini ezinamandla aphezulu kunye nokuqina okuhle. Iinxalenye zentsimbi etyhidiweyo kufuneka zicinywe kwaye zifudumale. Inkqubo yile: intsimbi etyhidiweyo ifudunyezwe kwiqondo lokushisa le-860-900 ° C kwaye ifakwe kwi-austenitize i-matrix, emva koko ipholile kwioli okanye ityuwa etyhidiweyo ukuze ifezekise ukucima, kwaye emva koko ifakwe kwiqondo lokushisa eliphezulu le-500-600 ° C ukuya. fumana isakhiwo se-troostite esinomsindo. (Ngokuphangaleleyo kusekho isixa esincinci se-ferrite enkulu esulungekileyo), kunye nokumila kwegraphite yoqobo engqukuva ayikatshintshi. Emva kokonyango, amandla kunye nokuqina kuhambelana kakuhle kwaye zifanelekile kwiimeko zokusebenza zamacandelo e-shaft.
2. Ukufakwa kwentsimbi ye-ductile ukuphucula ukuqina
Ngexesha lenkqubo yokuphosa i-iron ductile, i-iron yentsimbi eqhelekileyo inomkhwa omkhulu wobumhlophe kunye noxinzelelo olukhulu lwangaphakathi. Kunzima ukufumana i-ferrite ecocekileyo okanye i-pearlite matrix kwiindawo zentsimbi. Ukuze kuphuculwe i-ductility okanye ukuqina kweentsimbi zentsimbi, intsimbi etyhidiweyo idla ngokuba Amalungu aphinda afudunyezwe kwi-900-950 ° C kwaye agcinwe efudumele ixesha elaneleyo lokwenza i-annealing ephezulu yokushisa, kwaye emva koko ipholile ukuya kwi-600 ° C kwaye ipholile ngaphandle. eziko. Ngethuba le nkqubo, i-cementite kwi-matrix iyancipha ibe yigraphite, kwaye i-graphite iyancipha ukusuka kwi-austenite. Ezi grafiti ziqokelelana zijikeleze igraphite yokuqala engqukuva, kwaye imatrix iguqulwa ngokupheleleyo ibe yiferrite.
Ukuba ulwakhiwo lwe-as-cast luqulunqwe (i-ferrite + pearlite) i-matrix kunye ne-graphite eyi-spherical, ukwenzela ukuba kuphuculwe ubunzima, i-cementite kwi-pearlite idinga kuphela ukuchithwa kwaye iguqulwe ibe yi-ferrite kunye ne-spherical graphite. Ngenxa yale njongo, inxalenye yentsimbi kufuneka iphinde ifudunyezwe. Emva kokugqunywa phezulu nasezantsi kwiqondo lobushushu le-eutectoid le-700-760℃, iziko liyapholiswa ukuya ku-600℃ emva koko lipholiswe ngaphandle kweziko.
3. Ukulungelelanisa ukuphucula amandla entsimbi ye-ductile
Injongo ye-normalizing ductile iron kukuguqula isakhiwo se-matrix kwisakhiwo esihle se-pearlite. Inkqubo yokutshisa i-iron ductile casting kunye ne-matrix ye-ferrite kunye ne-pearlite kwiqondo lokushisa lama-850-900 ° C. I-ferrite yasekuqaleni kunye ne-pearlite iguqulwa ibe yi-austenite, kwaye enye i-graphite ye-spherical inyibilika kwi-austenite. Emva kokugcinwa kobushushu, i-austenite epholileyo yomoya iguqulela kwi-pearlite enhle, ngoko ke amandla e-ductile casting ayanda.
Ixesha lokuposa: May-08-2024
