Austenite - chii ichi?

Heat Mabatirwo simbi - ndiwo simba mashandiro ritibatsire ayo marongerwo uye zvivako. Kwakavakirwa okunatsiridza ose ari sekristaro yekamuri ave kushanda tembiricha chomutambo. Mamiriro ezvinhu akasiyana-siyana vari simbi-kabhoni chiwanikwa kunogona kuvapo ferrite, pearlite, cementite uye austenite. Ekupedzisira kukonzera yose chafariz transformations vari simbi.

tsananguro

Steel - ane chiwanikwa yedare kabhoni, sezvamakaropafadzwa kabhoni kugutsikana zviri 2.14% kuti dzidziso, asi zviri yemazuva ano kushanda unotora mune mari kwete kupfuura 1.3%. Saka, vose zvivako kuti akaumba mariri pasi Kufurirwa nevamwe, vari zvakare Variants alloys.

dzidziso Kuvapo kwavo 4 variations: kupinda rakasimba mhinduro, yakasimba kugadzirisa ane kunze, zvokuimba musanganiswa kana makemikari akakura mbeu.

Austenite - yakasimba kabhoni atomu granetsentricheskuyu kupinda mhinduro mune cubic sekristaro yekamuri simbi, anonzi γ. kabhoni atomu kutaurwa kupinda mhango pakati γ-yesimbi napamahwindo. miganhu yacho kupfuura pores avo pakati Fe maatomu, iro rinotsanangura shoma achipfuura navo achishandisa "rusvingo" zvimwe nengoro mamiriro. Kuvakwa panguva kushandurwa tembiricha kuti ferrite uye pearlite nokuwedzera kupisa 727˚S kumusoro.

The dhayagiramu iron-kabhoni alloys

Graph rinonzi danho dhayagiramu resimbi-cementite inovakwa kwacho, kuratidzwa pachena zvose zvinobvira dzakasiyana ose transformations mu steels vakakandira simbi. Dzinenge tsika kuti tembiricha akapiwa huwandu kabhoni iri chiwanikwa kuumba inokosha umo mune zvakakosha STRUCTURAL zvachinja kudziyisa kana kutonhora pezvakaitwa, ivo kuumba yakaoma mutsetse.

GSE mutsetse kuti rine pfungwa uye Ac ₃ Ac _m, anoratidza padanho kabhoni solubility pamwe kuwedzera kupisa mumatunhu.

edzidzo Features

Austenite - chivakwa inopfurwa panguva simbi kudziyisa. Apo tembiricha dzinonetsa kuumbika perlite uye ferrite chinokosha zvinhu.

kudziyisa variations:

1. Yunifomu, kusvikira asvika kutsvakwa kukosha, pfupi Excerpt kutonhora. Zvichienderana zvechadenga chiwanikwa, kuti austenite ingangoumbwa somunhu zvakakwana kana zvisina kukwana.
2. The anononoka kuwedzera kupisa, yakareba tiine kubudirira nenhanho kupisa kuumba yakachena austenite.

The ehupfumi of nharo huru zvokunyama, uyewo icho kwaizoitika somugumisiro kutonhora. Zvakawanda zvinoenderana padanho kubudirira nokupisa. Zvakakosha kudzivisa overheating kana perepal.

Microstructure uye Properties

Mumwe nomumwe maitikiro, hwokufananidzira esimbi-kabhoni alloys, vanowanzotevedzera varidzi maumbirwo arrays uye tsanga. austenite mamiriro - ndiro kuva chimiro pedyo tsono-zvakadai uye pfungwa, uye chinopfupfuduka. Kana ichiputswa zvakazara kabhoni iri γ-simbi tsanga vane chimiro pasina chiedza nerima cementite inclusions.

The neukukutu 170-220 HB. Thermal uye zvemagetsi conductivity dererei pane ferrite. Magnetic ehupfumi havasi kuwanika.

Variants uye kutonhora mwero kunoita kuti paumbwe shanduro dzakasiyana-siyana pakati "chando" nehurumende: martensite, bainite, troostite, sorbitol, perlite. Vane tsono-kufanana yakarongeka, asi zvakasiyana PARTICIPLE vakapararira, zviyo kukura uye cementite PARTICIPLE.

Zvinoitwa kutonhora austenite

kuora austenite kunoitika chete dzinonetsa pfungwa. Kugona kwaro kunobva zvinhu zvinotevera:

1. Mwero kutonhora. Zvarinoita hunhu carbon netsvina, paumbwe tsanga, paumbwe yokupedzisira microstructure uye ayo zvivako. It zvinoenderana zvakatipoteredza, iro rinoshandiswa senzira coolant.
2. Availability isothermal chezvinonhuwira rimwe nzendo kuora - iri akatura kuna imwe tembiricha sandara, kupisa anodzokororwa yakatsiga panguva imwe nguva, pashure iyo nokukurumidza kutonhora zviri mberi, kana kana kunoitika pachiimbwa ine kudziyisa midziyo (hovhoni).

Saka, zindoga uye kuramba isothermal kusanduka austenite.

Features hunhu transformations. chati

C-zvakaumbwa girafu inoratidza muenzaniso yekupindurwa simbi microstructure panguva penguva zvichienderana tembiricha change - ichi austenite kushanduka chati. The chaiko kutonhora dzose. Kune chete zvimwe zvikamu vanomanikidzwa kupisa chengetedzo. The girafu anorondedzera isothermal ezvinhu.

Character inogona diffuse uye Diffusionless.

At mureza nokukurumidza shanduko kuderedza kupisa diffusion austenite tsanga kunoitika. The thermodynamic maatomu kusagadzikana mapazi kutanga kufamba pamwe chete. Avo vasina vanokwanisa kupinda simbi yekamuri, zvinoumba cementite inclusions. Vari akabatana ne pedyo tudonhwe kabhoni, asunungurwa crystals ayo. Cementite achiumbwa panguva miganhu yacho tsanga kuparara. Yakanatswa crystals vanoumba dzakasiyana ferrite ndiro. Vakapararira mamiriro aumbwa - musanganiswa zviyo, kukura uye mumisasa izvo kunoenderana rapidity kuti kutonhora uye zviri kabhoni iri chiwanikwa. Kuvakwa sezvo perlite yaro zvenguva maitikiro: sorbitol, troostite, bainite.

With chinokosha nokukurumidza rutapudzo tembiricha austenite manyowa usingatadzi diffusive zvisikwa. Complex mechanical kusarurama yokuvamba mukati iro maatomu pose kufamba mune ndege pasina kuchinja nzvimbo. Kushaya diffusion kunoita kuti kwaita martensite.

The mugumisiro richipedza pamusoro austenite manyowa unhu. martensite

Nokuomesa - rudzi kupisa kurapwa, izvo chaizvoizvo kunoratidzwa akurumidze kudziyisa kusvikira kumusoro tembiricha pamusoro inokosha uye Ac ₃ Ac _m, zvichiteverwa nokukurumidza kutonhora. Kana kuderera tembiricha kunoitika nemvura ari kumhanya anopfuura 200 ° C pa wechipiri, ipapo yakasimba acicular danho rine martensite zita.

Zviri supersaturated yakasimba mhinduro kubva kabhoni iri kupinda simbi mhando sekristaro zvakachinjikwa pamwe α. Nokuda simba kufamba maatomu ari akavhiringika uye anoumba munhu tetragonal yekamuri kuti inoshanda chikonzero nokuomesa. The akaumba mamiriro ane vhoriyamu yakakura. The zvichiguma crystals vakanga rakatenderedzwa ndege compressed nucleate acicular kwamahwendefa.

Martensite - Zvinokosha zvakaisvonaka uye zvakaoma chaizvo (700-750 HB). Akaumba chete somugumisiro soro-nokukurumidza richipedza.

Tempering. diffusion mamiriro

Austenite - ndiro paumbwe izvo zvinogona artificially yakabereka bainite, troostite, sorbite, uye perlite. Kana richipedza kutonhora kunoitika nokuda dzakaderera velocities, kutendeuka pavaiita diffusion, mashandiro avo anotsanangurwa kumusoro.

Troost - ndiko perlite, iyo inozivikanwa nokuva refu mwero kupararira. Kuvakwa pa 100 ° C kuderera richipisa pakarepo. A vazhinji yakaisvonaka remakungwa ferrite uye cementite riri kuparadzirwa pamusoro rose ndege. "Akaomesa" chairwo cementite ndiro chimiro uye troostite kunokonzerwa unozotevera tempering, ane granular Visualization. Pokuoma - HB 600-650.

Bainite - ane zvenguva kutotanga, kuri kunyanya crystals mukuru-vakapararira vasanganise ferrite uye cementite. Maererano zvemaziso uye kwesayenzi zvivako hwakaderera martensite, asi anopfuura troostite. Akaumba mukati tembiricha siyana apo diffusion zvisingaiti uye compression simba uye kufambisa crystalline mamiriro kutendeutsa kuti martensite - kukwana.

Sorbitol - vakasindimara acicular siyana pearlitic maitikiro pa kutonhora mwero 10 ° C muzana wechipiri. Zvokuimba basa ehupfumi vari zvenguva pakati troostite uye pearlite.

Perlite - a muzvizhinji kuti remakungwa ferrite uye cementite, izvo zvingava granular, kana ndiro chimiro. Akaumba somugumisiro kumeso manyowa pakati austenite panguva kutonhora zvazvingava 1˚S por wechipiri.

KuBheti troostite uye - kureva kudzima zvivako, apo sorbitol uye perlite inogona kuumbwa uye tempering, annealing uye normalizing zvinhu izvo kutsanangura chimiro uye kukura mbeu.

Mugumisiro annealing pamusoro chaiwo austenite manyowa

Zvinenge zvose Mhando annealing uye normalization kwakavakirwa itirana kuchinja austenite. Full uye chikamu-nguva annealing inoshandiswa doevtektoidnyh steels. Details neshungu mu sechoto pamusoro dzinonetsa pfungwa Ac ₁ uye Ac _3, ukuwo. Wokutanga mhando kunoratidzwa munhu kwenguva refu dzokupisa nguva, izvo zvinoita kutendeuka zvakakwana: austenite-ferrite-austenite uye pearlite. Uchiteverwa anononoka kutonhora billets muchoto. Panguva goho kupa wakanaka vasanganise ferrite uye pearlite, pasina munyika zvinetso uye epurasitiki chikukutu. Soft annealing zvishoma simba-nyanyisa, chete anochinja maumbirwo perlite, ferrite kusiya kumbochinja zvachose. Normalization chinoreva yakakwirira Zvisinei mwero tembiricha kuchembera,, zvakawanda mapurasitiki uye zvishoma zvinonyadzisa chivako panguva nzira yokubudisa. Nokuti simbi chiwanikwa ane kabhoni zviri kubva 0,8 kusvika 1,3% kana dzaserera ari normalization kuora kunoitika kurutivi: austenite, pearlite, austenite-cementite.

Rumwe rudzi kupisa kurapwa iyo inobva STRUCTURAL transformations, ndiye homogenisation. Zviri kushandiswawo guru nhengo. Rinoreva Mhedziso kuwana zvinonyadzisa austenitic ezvinhu panguva tembiricha 1000-1200˚S uye kutsungirira muvira munguva maawa 15. Isothermal pezvakaitwa vanoramba anonoke kutonhora, izvo zvinoita kuti equalization yacho simbi zvivako.

isothermal annealing

Mumwe nomumwe Nzira idzi kufurira simbi Pakufambisa njere sechinoitika isothermal kusanduka austenite. Zvisinei, mumwe nomumwe wavo chete panguva imwe Danho ane unhu. Chaizvoizvo, kuchinja nokuitika vachiwana kuderera nokupisa, kumhanya iyo anosarudza mugumisiro.

Imwe nzira iri pedyo akanyatsokodzera ezvinhu - isothermal annealing. Chaizvoizvo wayo kunoratidzwa kudziyisa uye kuona kuti wakakwana kuparara zvivako zvose zviri austenite. The kutonhora chaitwa mune maitikiro dzinoverengeka, izvo zvinoita kuti munhu nomumugwagwa kwaitora nguva, vakawanda kwenguva yakareba uye zvikuru thermally kugadzikana yokushata kwayo.

1. Kufambira donhwe tembiricha kuti ukoshi pazasi 100 ° C kuna Ac ₁ pfungwa.
2. Kudzosera chengetedzo yakawana ukoshi (akaisa muchoto) kwenguva refu kusvikira pokupedza paumbwe imwe ferritic-pearlitic maitikiro.
3. Kutonhora mu achiri mudenga.

Nzira rinoshanda kuti chiwanikwa steels, izvo dzinoratidzwa nokuvapo residual austenite vari refrigerated mamiriro.

Residual austenite uye austenitic steels

Dzimwe zvinokwanisika haasaruri kuora, kana pane residual austenite. Izvi zvinogona kuitika mumamiriro anotevera:

1. Too nokukurumidza kutonhora kana Kuparara zvakakwana kunoitika. Zviri STRUCTURAL chezvinonhuwira bainite kana martensite.
2. High kabhoni simbi kana yakaderera chiwanikwa, uhwo pezvakaitwa vari kuoma vakapararira austenite transformations. Zvinoda kushandiswa chinokosha kupisa kurapa nzira dzakadai Somuenzaniso, homogenization kana isothermal annealing.

For high-- No muitiro kunorondedzerwa transformations. Alloying simbi pamwe nickel, manganese, chromium inosimudzira paumbwe austenite sezvo chikuru mamiriro hwakasimba izvo haatarisiri okuwedzera zvinofurira. Austenitic steels dzinoratidzwa nesimba mukuru, ngura kuzvidzivirira uye kupisa nemishonga, kupisa kurwisa kuramba nehasha kushanda ezvinhu akaoma.

Austenite - marongerwo riri hazviiti pasina nokuumba hapana mukuru-tembiricha kudziyisa hwendarira uye izvo rinobatanidzwa zvinenge zvose zvayo kupisa kurapwa nzira kuvandudza zvemaziso uye kugadzira nzvimbo.