Kune akati wandei anowanzo shandiswa kupisa kupisa nzira dze ductile iron.
Muchimiro che ductile iron, girafu ine spherical, uye kupera kwayo uye kukuvadza mhedzisiro pamatrix haina simba kupfuura iyo yeflake graphite. Kuita kwe ductile iron kunonyanya kuenderana nematrix chimiro, uye pesvedzero yegraphite ndeyechipiri. Kuvandudza matrix chimiro che ductile iron kuburikidza neakasiyana kupisa marapirwo anogona kuvandudza ma mechanic zvivakwa kune akasiyana madhigirii. Nekuda kwesimba rekuumbwa kwemakemikari, chiyero chekutonhora, spheroidizing agent uye zvimwe zvinhu, yakasanganiswa chimiro cheferrite + pearlite + cementite + graphite inowanzoonekwa mune as-cast chimiro, kunyanya pamadziro akaonda ekukanda. Chinangwa chekurapa kwekupisa ndechekuwana chimiro chinodiwa uye nekudaro kuvandudza ma mechanical properties.
Inowanzo shandiswa kupisa kupisa nzira dze ductile iron ndedzinotevera.
(1) Low-tembiricha graphitization annealing kudziyisa tembiricha 720 ~ 760 ℃. Inotonhodzwa muchoto kusvika pasi pe500 ℃ uye yobva yatonhodzwa nemhepo. Bvisa iyo eutectoid cementite kuti uwane ductile iron ine ferrite matrix kuvandudza kuoma.
(2) High-temperature graphitization annealing pa880 ~ 930 ℃, yozoendeswa ku720 ~ 760 ℃ yekuchengetedza kupisa, yozotonhodzwa nechoto ichienda pasi pe500 ℃ uye mhepo-inotonhorera kunze kwechoto. Bvisa chimiro chichena uye uwane ductile iron ine ferrite matrix, iyo inovandudza plastiki, inoderedza kuoma uye inowedzera kuoma.
(3) Kuzadza austenitization uye normalizing pa880 ~ 930 ℃, kutonhora nzira: mhute kutonhora, kutonhora kwemhepo kana kutonhora kwemhepo. Kuti uderedze kushushikana, wedzera tempering muitiro: 500 ~ 600 ℃ kuwana pearlite + shoma shoma ferrite + spherical chimiro Graphite, iyo inowedzera simba, kuoma uye kupfeka kuramba.
(4) Kusakwana austenitization, normalizing uye kupisa pa820 ~ 860 ℃, kutonhora nzira: mhute kutonhora, kutonhora kwemhepo kana kutonhora kwemhepo. Kuti uderedze kushushikana, wedzera tempering process: 500 ~ 600 ℃ kuti uwane pearlite + shoma shoma yesimbi yakapararira Chimiro chemuviri chinowana zvirinani zvakakwana zvemichina.
(5) Kudzima uye kudziya kurapwa: kupisa pa840 ~ 880 ° C, kutonhora nzira: mafuta kana mvura kutonhora, kupisa tembiricha mushure mekudzima: 550 ~ 600 ° C, kuwana hutsinye sorbite chimiro uye kuvandudza yakazara ma mechanical properties.
(6) Isothermal quenching: Kupisa pa840 ~ 880 ℃ uye kudzima mubhati remunyu pa250 ~ 350 ℃ kuti uwane huchenjeri hwemagetsi, kunyanya kuvandudza simba, kusimba uye kupfeka kuramba.
Munguva yekupisa nekudziya, tembiricha yekukanda inopinda muchoto kazhinji isingasviki 350 ° C. Kupisa kwekupisa kunoenderana nehukuru uye kuoma kwekukandira, uye inosarudzwa pakati pe30 ~ 120 ° C/h. Iyo tembiricha yekupinda muchoto yezvikamu zvakakura uye zvakaoma zvinofanirwa kunge zvakaderera uye mwero wekupisa unofanirwa kunonoka. Kupisa kwekupisa kunoenderana nechimiro chematrix uye chimiro chemakemikari. Nguva yekubata inobva pamadziro emadziro ekukanda.
Uye zvakare, ductile iron castings inogona zvakare kudzimwa pamusoro uchishandisa yakakwira frequency, yepakati frequency, murazvo uye dzimwe nzira dzekuwana kuomarara kwakanyanya, kupfeka kuramba uye kuneta kuramba. Inogona zvakare kurapwa neiyo nitriding yakapfava yekuvandudza kupfeka kuramba kwecastings.
1.Kudzima uye kupisa kurapwa kwe ductile iron
Ductile castings inoda kuomarara kwepamusoro semabhengi, uye zvikamu zvesimbi zvakakandwa zvinowanzodzimwa nekudzikamiswa patembiricha yakaderera. Maitiro acho ndeokuti: kupisa kukanda kune tembiricha ye860-900 ° C, kuivharira kuti ibvumidze ese epakutanga matrix kuti austenitize, wozoitonhodza mumafuta kana munyu wakanyungudutswa kuti uwane kudzimwa, uye wozodziya nekuichengeta pa250-350. °C yekudziya, uye iyo yekutanga matrix inoshandurwa kuita Moto martensite uye yakachengetwa austenite chimiro, iyo yekutanga spherical graphite chimiro inoramba isina kuchinjika. Iwo akarapwa akakandwa ane kuomarara kwakanyanya uye kumwe kuomarara, anochengeta mafuta ekuzora egraphite, uye akavandudza kusapfeka.
Ductile iron castings, sezvikamu zveshaft, senge crankshafts uye matanda ekubatanidza einjini dzedhiziri, inoda huwandu hwemagetsi zvivakwa zvine simba rakakura uye kusimba kwakanaka. Nhengo dzesimbi dzakaumbwa dzinofanira kudzimwa uye kudzikamiswa. Maitiro acho ndeokuti: simbi yakakandwa inopisa kusvika kune tembiricha ye860-900 ° C uye insulated kuti austenitize matrix, yobva yanyoroveswa mumafuta kana munyu wakanyungudutswa kuti uwane kudzimwa, uye wobva wanyungudutswa pakupisa kwe500-600 ° C kusvika. kuwana hasha troostite chimiro. (Kazhinji kuchine hushoma hwakachena hombe ferrite), uye chimiro chepakutanga spherical graphite chinoramba chisina kuchinjika. Mushure mekurapa, kusimba uye kusimba zvinowirirana zvakanaka uye zvakakodzera kumamiriro ekushanda ezvikamu zve shaft.
2. Annealing ye ductile iron kuvandudza kuoma
Munguva yekukanda maitiro e ductile iron, yakajairwa grey cast iron ine yakakura kuchena maitiro uye yakakura kushushikana kwemukati. Zvakaoma kuwana ferrite yakachena kana pearlite matrix yezvikamu zvesimbi zvakakandwa. Kuti uvandudze ductility kana kuoma kwesimbi yakakandwa zvikamu, simbi yakakandwa kazhinji Izvo zvikamu zvinopiswa zvakare kusvika 900-950 ° C uye zvinoramba zvichidziya kwenguva yakakwana kuti iite yakakwirira-tembiricha annealing, uye yozotonhorera kusvika 600 ° C uye yatonhodzwa kunze. chevira. Munguva yekuita, simenti mumatrix inoora kuita graphite, uye graphite inonatswa kubva ku austenite. Aya magirafu anoungana akatenderedza yekutanga spherical graphite, uye matrix inoshandurwa zvachose kuita ferrite.
Kana iyo as-cast structure inoumbwa ne (ferrite + pearlite) matrix uye spherical graphite, kuitira kuti uvandudze kuoma, simenti mu pearlite inongoda kuparara uye kuchinjwa kuva ferrite uye spherical graphite. Nechinangwa ichi, chikamu chesimbi chakaumbwa chinofanira kupiswa zvakare. Mushure mekuiswa insulated kumusoro nekudzika tembiricha yeeutectoid ye700-760 ℃, choto chinotonhodzwa kusvika pa600 ℃ chobva chatonhodzwa kunze kwechoto.
3. Normalizing kuvandudza simba ductile iron
Chinangwa che normalizing ductile iron ndeye kushandura matrix chimiro kuita yakanaka pearlite chimiro. Iyo nzira ndeyekupisa zvakare ductile iron casting ine matrix yeferrite uye pearlite kune tembiricha ye850-900 ° C. Iyo yekutanga ferrite uye pearlite inoshandurwa kuita austenite, uye imwe spherical graphite inonyungudika mu austenite. Mushure mekuchengetedza kupisa, iyo air-cooled austenite inoshandura kuita pearlite yakanaka, saka simba rekukanda ductile rinowedzera.
Nguva yekutumira: Chivabvu-08-2024
