Kunezindlela ezimbalwa ezivame ukusetshenziswa zokwelashwa kokushisa kwe-ductile iron.
Esakhiweni se-iron ductile, i-graphite iyindilinga, futhi umphumela wayo obuthakathaka futhi olimazayo ku-matrix ubuthakathaka kunalowo we-flake graphite. Ukusebenza kwe-iron ductile ikakhulukazi kuncike esakhiweni se-matrix, futhi umthelela we-graphite ungowesibili. Ukuthuthukisa ukwakheka kwe-matrix yensimbi ye-ductile ngokusebenzisa ukwelashwa okuhlukahlukene kokushisa kungathuthukisa izici zayo zemishini ngamazinga ahlukahlukene. Ngenxa yethonya lokwakheka kwamakhemikhali, izinga lokupholisa, i-ejenti ye-spheroidizing nezinye izici, isakhiwo esixubile se-ferrite + pearlite + cementite + graphite sivame ukuvela esakhiweni se-as-cast, ikakhulukazi odongeni oluncane lokuphonsa. Inhloso yokwelashwa kokushisa ukuthola isakhiwo esidingekayo futhi ngaleyo ndlela kuthuthukiswe izakhiwo zemishini.
Izindlela ezijwayelekile zokwelashwa kokushisa kwe-ductile iron yilezi ezilandelayo.
(1) Izinga lokushisa eliphansi le-graphitization annealing lokushisa lokushisa 720 ~ 760 ℃. Ipholiswa esithandweni ibe ngaphansi kuka-500℃ bese ipholiswa ngomoya. Bolisa i-eutectoid cementite ukuze uthole insimbi eyi-ductile ene-ferrite matrix ukuze uthuthukise ukuqina.
(2) I-graphitization yokushisa ephezulu yokushisa ku-880 ~ 930 ℃, bese idluliselwa ku-720 ~ 760 ℃ ukuze kugcinwe ukushisa, bese ipholiswa ngesithando somlilo ibe ngaphansi kuka-500 ℃ futhi ipholiswe umoya ngaphandle kwesithando. Susa ukwakheka okumhlophe futhi uthole i-ductile iron ene-ferrite matrix, ethuthukisa ipulasitiki, inciphise ubulukhuni futhi ikhulise ukuqina.
(3) I-austenitization ephelele kanye nokujwayelekile ku-880 ~ 930 ℃, indlela yokupholisa: ukupholisa inkungu, ukupholisa komoya noma ukupholisa umoya. Ukuze unciphise ukucindezeleka, engeza inqubo yokushisa: 500 ~ 600℃ ukuthola i-pearlite + inani elincane le-ferrite + i-spherical shape Graphite, okwandisa amandla, ubulukhuni nokumelana nokugqoka.
(4) I-austenitization engaphelele, ukujwayela nokushisisa ku-820 ~ 860 ℃, indlela yokupholisa: ukupholisa inkungu, ukupholisa komoya noma ukupholisa umoya. Ukuze unciphise ukucindezeleka, engeza inqubo yokushisa: 500 ~ 600 ℃ ukuze uthole i-pearlite + inani elincane lensimbi ehlakazekile Isakhiwo somzimba sifinyelela izici ezingcono eziphelele zemishini.
(5) Ukwelashwa kokucisha nokushisa: ukushisa ku-840 ~ 880 ° C, indlela yokupholisa: ukupholisa uwoyela noma amanzi, izinga lokushisa elipholile ngemva kokucisha: 550 ~ 600 ° C, ukuthola isakhiwo se-sorbite esiphundu futhi kuthuthukiswe izakhiwo zemishini ezibanzi.
(6) Ukucisha i-Isothermal: Ukushisa ku-840 ~ 880℃ nokucisha kubhavu kasawoti ku-250 ~ 350℃ ukuze kutholwe izici ezibanzi zemishini, ikakhulukazi ukuthuthukisa amandla, ukuqina nokumelana nokugqoka.
Ngesikhathi sokwelashwa kokushisa nokushisa, izinga lokushisa lokuphonsa elingena esithandweni ngokuvamile lingaphansi kuka-350 ° C. Isivinini sokushisisa sincike kusayizi nobunkimbinkimbi bokusakaza, futhi sikhethwa phakathi kuka-30~120°C/h. Izinga lokushisa lokungena esithandweni sezingxenye ezinkulu neziyinkimbinkimbi kufanele libe phansi futhi izinga lokushisa kufanele lihambe kancane. Izinga lokushisa lokushisa lincike esakhiweni se-matrix kanye nokwakheka kwamakhemikhali. Isikhathi sokubamba sincike ekugqineni kodonga lokubunjwa.
Ngaphezu kwalokho, ukukhishwa kwe-iron ductile kungabuye kucinywe phezulu kusetshenziswa imvamisa ephezulu, imvamisa ephakathi, ilangabi nezinye izindlela zokuthola ubulukhuni obuphezulu, ukumelana nokugqoka kanye nokumelana nokukhathala. Ingase futhi iphathwe nge-nitriding ethambile ukuze kuthuthukiswe ukumelana nokugqokwa kwama-castings.
1.Ukucisha kanye nokwelashwa kwe-ductile iron
Ama-Ductile castings adinga ubulukhuni obuphakeme njengama-bearings, futhi izingxenye zensimbi ezisansimbi zivame ukucishwa futhi zifudumale emazingeni okushisa aphansi. Inqubo iwukuthi: ukushisa ukubunjwa kumazinga okushisa angama-860-900 ° C, ukuyivikela ukuze uvumele yonke i-matrix yokuqala ukuba i-austenitize, bese uyipholisa emafutheni noma usawoti oncibilikisiwe ukuze ufeze ukucisha, bese uyishisa futhi uyigcine ku-250-350. °C yokushisa, futhi i-matrix yasekuqaleni iguqulwa ibe yi-Fire martensite futhi igcinwe isakhiwo se-austenite, umumo wangempela oyindilinga wegraphite uhlala ungashintshiwe. Ama-castings alashiwe anokuqina okuphezulu kanye nokuqina okuthile, agcina izici zokuthambisa zegraphite, futhi athuthukise ukumelana nokugqokwa.
I-Ductile iron castings, njengezingxenye ze-shaft, njengama-crankshafts nezinduku zokuxhuma zezinjini zikadizili, zidinga izakhiwo zemishini ezibanzi ezinamandla aphezulu kanye nokuqina okuhle. Izingxenye ze-cast iron kufanele zicinywe futhi zifuthe. Inqubo iwukuthi: insimbi ekhonjiwe iyashiswa ekushiseni kwe-860-900 ° C futhi ifakwe i-austenitize i-matrix, bese ipholiswa emafutheni noma usawoti oncibilikisiwe ukuze ifinyelele ukucisha, bese ifakwa ekushiseni okuphezulu kwe-500-600 ° C kuya thola isakhiwo se-troostite esithambile. (Ngokuvamile kusekhona inani elincane le-ferrite enkulu emsulwa), futhi ukuma kwe-graphite yasekuqaleni eyindilinga kuhlala kungashintshile. Ngemuva kokwelashwa, amandla nokuqina kuhambisana kahle futhi kufanelekile izimo zokusebenza zezingxenye ze-shaft.
2. Ukufakwa kwe-iron ductile ukuze kuthuthukiswe ukuqina
Phakathi nenqubo yokukhipha i-ductile iron, insimbi evamile empunga inomkhuba omkhulu wokuba mhlophe kanye nengcindezi enkulu yangaphakathi. Kunzima ukuthola i-ferrite ehlanzekile noma i-matrix ye-pearlite yezingxenye zensimbi. Ukuze kuthuthukiswe i-ductility noma ukuqina kwezingxenye zensimbi ekhonjiwe, insimbi yokusansimbi imvamisa Izingxenye zishiselwa kabusha ziye ku-900-950 ° C futhi zigcinwe zifudumele isikhathi esanele ukuze zenze i-annealing yokushisa ephezulu, bese zipholiswa ku-600 ° C futhi zipholile ngaphandle. wesithando somlilo. Phakathi nenqubo, i-cementite ku-matrix ibola ibe i-graphite, futhi i-graphite iyancipha isuka ku-austenite. Lawa magraphite aqoqana azungeze i-graphite yokuqala eyindilinga, futhi i-matrix iguqulwa ngokuphelele ibe i-ferrite.
Uma isakhiwo se-as-cast sakhiwe (i-ferrite + pearlite) matrix kanye ne-graphite eyindilinga, ukuze kuthuthukiswe ukuqina, i-cementite ku-pearlite idinga kuphela ukubola futhi iguqulwe ibe i-graphite ye-ferrite ne-spherical. Ngale njongo, ingxenye yensimbi ekhonjiwe kufanele ishiswe kabusha. Ngemva kokugqunywa phezulu naphansi kwezinga lokushisa le-eutectoid elingu-700-760℃, isithando somlilo siyapholiswa sibe ku-600℃ bese siyapholiswa siphume esithandweni.
3. Normalizing ukuthuthukisa amandla ductile iron
Inhloso ye-normalizing iron ductile ukuguqula isakhiwo se-matrix sibe isakhiwo esihle se-pearlite. Inqubo iwukushisisa kabusha i-ductile iron casting nge-matrix ye-ferrite ne-pearlite ekushiseni kuka-850-900°C. I-ferrite yasekuqaleni ne-pearlite iguqulwa ibe yi-austenite, futhi enye i-graphite eyindilinga iyancibilika ku-austenite. Ngemuva kokugcinwa kokushisa, i-austenite epholile emoyeni ishintsha ibe i-pearlite enhle, ngakho amandla okukhishwa kwe-ductile ayanda.
Isikhathi sokuthumela: May-08-2024
