Austenite - ndi chiyani ichi?

Kutentha mankhwala ndi zitsulo - ndi limagwirira mphamvu yosokoneza matabwa ake ndi katundu. Bukuli lili zosintha wa kophimba amaoneka ngati ntchito ya kutentha kwa masewera. Zikhalidwe zosiyanasiyana aloyi chitsulo mpweya angathe kupezeka ferrite, pearlite, cementite ndi austenite. Yotsirizira n'chofunikira zikuluzikulu zonse masinthidwe matenthedwe mu zitsulo.

tanthauzo

Zitsulo - ndi aloyi chitsulo ndi mpweya, mmene zili mpweya ndi kwa 2,14% ya chiphunzitso, koma ndi sayansi limapangidwa amagwira ntchito ndalama osapitirira 1.3%. Motero, nyumba yonse imene anapanga m'menemo pansi makhalidwe kunja, nawonso mitundu kasakaniza wazitsulo.

chiphunzitso ndi moyo wawo mu 4 yofanana: malowedwe olimba njira yothetsera olimba a zosiyana osakaniza makina kapena mankhwala pawiri mbewu.

Austenite - olimba mpweya atomu granetsentricheskuyu malowedwe njira mu kiyubiki galasi latisi yachitsulo, amatchedwa γ. mpweya atomu anadzetsa M'mimbamo wa latisi γ zitsulo. miyeso yake upambana pores anthu pakati Fe maatomu, lomwe limafotokoza zochepa kudutsa iwo mwa "khoma" kapangidwe m'munsi. Inakhazikitsidwa m'zaka kusintha kutentha kwa ferrite ndi pearlite ndi kuwonjezeka 727˚S kutentha pamwamba.

Chithunzi cha kasakaniza wazitsulo chitsulo mpweya

Chithunzi otchedwa gawo chithunzi cha chitsulo-cementite inamangidwa ndi kuyesera, ndi zinasonyeza bwino mitundu n'kotheka a kusinthika mu steels ndi zitsulo chosungunula. makhalidwe enieni kutentha anapatsidwa kuchuluka kwa mpweya mu aloyi ndi kupanga mfundo owawitsa omwe pali zofunika kusintha structural mu Kutentha kapena kuzirala njira, iwo kupanga mzere yovuta.

GSE mzere kuti ndi mfundo ndi Mac ₃ Mac _m, amasonyeza mlingo wa mpweya solubility ndi amaika kutentha.

Features yophunzitsa

Austenite - dongosolo kuti aumbike pa zitsulo Kutentha. Pamene kutentha yovuta kupanga perlite ndi ferrite yofunika zakuthupi.

Kutentha yofanana:

1. Yunifolomu, mpaka kufika mtengo wolakalakika, ndi kagawo mwachidule yozizira. Malinga ndi makhalidwe a aloyi, ndi austenite akhoza kupangidwa ngati kwathunthu kapena pang'ono.
2. Kukwera pang'onopang'ono kutentha, nthawi yaitali kukhalabe mlingo akwaniritsa kutentha kupanga austenite koyera.

The katundu wa zinthu mkangano, komanso chimene chidzachitika chifukwa cha kuzirala. Zikudalira mlingo zimatheka ndi kutentha. Nkofunika kupewa kutenthedwa kapena perepal.

Microstructure ndi katundu

Aliyense wa magawo ndi, ankaikira kasakaniza wazitsulo chitsulo mpweya, amakonda kukhala ndi dongosolo la magulu ndi mbewu. austenite kapangidwe - mbale ndi mawonekedwe pafupi ndi singano ngati ndi malingaliro, ndipo flaky. Pamene kwathunthu kusungunuka mpweya mu mbewu γ zitsulo ndi mawonekedwe opanda kuwala mdima inclusions cementite.

The kuuma 170-220 HB. Matenthedwe ndi magetsi madutsidwe n'chozama kuposa ferrite. katundu maginito palibe.

Mitundu ndi yozizira mlingo kumabweretsa mapangidwe Mabaibulo osiyanasiyana a "ozizira" amati: martensite, bainite, troostite, sorbitol, perlite. Iwo ndi singano ngati dongosolo, koma osiyana tinthu kupezeka, kukula tirigu ndi cementite tinthu.

Mphamvu ya yozizira austenite

austenite kuwola amapezeka mfundo yomweyo yovuta. nchito zake kumatengera zifukwa zotsatirazi:

1. Mlingo wa kuzirala. Amakhudza chikhalidwe cha zodetsa ndi mpweya mapangidwe mbewu, mapangidwe ndi microstructure komaliza ndi katundu wake. Izo zimatengera chilengedwe, amene ntchito ngati coolant a.
2. Kapezekedwe isothermal chigawo chimodzi pa limodzi la magawo a kuwola - ndi adatchithisira linalake mlingo kutentha, kutentha anakhalabe khola panthawi imodzi, pambuyo pake kuzirala mofulumira ikupitirira, kapena kumachitika molumikizana ndi Kutentha zida (uvuni).

Choncho, akutali ndi mosalekeza isothermal wasinthika austenite.

Features cha masinthidwe khalidwe. tchati

C-zooneka Zithunzi izo zikusonyeza chitsanzo cha kusintha kwa microstructure zitsulo mu nthawi imeneyi malingana ndi kusintha kutentha - ichi austenite kusintha chithunzi. Kuzirala leni mosalekeza. Pali yekha mbali zina amakakamizidwa kutentha posungira. The Zithunzi akufotokoza mikhalidwe ya isothermal.

Khalidwe sangakhoze kukhala akakufunsani ndi Diffusionless.

Pa kusintha muyezo liwiro kuchepetsa kutentha mayamwidwe austenite mbewu amapezeka. The thermodynamic Kusakhazikika zone maatomu anayamba kusunthira pamodzi. Amene sakwanitsa kudutsa chitsulo latisi, kupanga inclusions cementite. Likugwirizana ndi oyandikana nawo particles mpweya, anamasulidwa ndi timibulu ake. Cementite aumbike pa malire a mbewu asamathe. timibulu woyeretsedwa zimapanga ziwalo ferrite mbale. Omwazika dongosolo aumbike - chisakanizo cha mbewu, kukula ndi ambiri omwe zimadalira mofulumira ya kuzirala ndi ochititsa mpweya mu aloyi lapansi. Kupangidwa ngati perlite ndi magawo ake wapakatikati: sorbitol, troostite, bainite.

Ndi kutentha kuchepetsa kwambiri liwiro austenite kuwonongeka sakutero diffusive chikhalidwe. Zovuta galasi kupotoza zochitika mu zomwe maatomu onse pa nthawi imodzi kusuntha mu ndege popanda kusintha malo. Chosowa mayamwidwe kumathandiza kuti zikamera wa martensite.

Zotsatira lakhala pa makhalidwe austenite kuwonongeka. martensite

Kuwuma - choyimira cha kutentha mankhwala, zomwe kwenikweni tichipeza mu mofulumira Kutentha kwa kutentha pamwamba mfundo yovuta, ndiponso Mac ₃ Mac _m, namtsata ndi kuzirala mofulumira. Ngati kuchepa kutentha chikuchitika ndi madzi pa liwiro la zoposa 200 ° C pa mphindi, ndiye olimba acicular gawo ndi martensite dzina.

Ndi supersaturated olimba njira ya mpweya mu malowedwe chitsulo mtundu galasi latisi ndi α. Chifukwa cha amphamvu kayendedwe maatomu ndi oipa ndiponso ndipamene latisi tetragonal kuti akutumikira chifukwa oipa. Kapangidwe anapanga ali buku zikuluzikulu. The makhiristo chifukwa anali njanjira ndege wothinikizidwa nucleate acicular mbale.

Martensite - cholimba ndi zovuta kwambiri (700-750 HB). Anapanga yekha chifukwa lakhala mkulu-liwiro.

Tempering. mayamwidwe kapangidwe

Austenite - ndi mapangidwe sipangakhalenso chongopeka opangidwa bainite, troostite, sorbite, ndi perlite. Ngati Kuthetsa kuzirala kumachitika chifukwa velocities m'munsi, kutembenuka ikuchitika mayamwidwe, limagwirira awo tafotokozazi.

Troost - ndi perlite, amene amakhala ndi digiri yapamwamba ya kupezeka. Anapanga pa 100 ° C kuchepa kutentha kwa mphindi. A ambiri mbewu zabwino za ferrite ndi cementite ndi anagawira pa ndege lonse. "Anaumitsa" achilendo cementite mbale mawonekedwe ndi troostite chifukwa tempering wotsatira, ali ndi granular zowonera. Kuuma - HB 600-650.

Bainite - ndi gawo wapakatikati, chomwe ndi timibulu ochuluka osakaniza mkulu-anabalalitsidwa ferrite ndi cementite. Malinga mawotchi ndi sayansi katundu wochepa ndi martensite, koma kuposa troostite. Kupangidwa mu kutentha osiyanasiyana kumene mayamwidwe chosatheka ndi mphamvu psinjika ndi kusuntha kapangidwe crystalline kutembenuka kwa martensite - osakwanira.

Sorbitol - pa coarse acicular zosiyanasiyana pearlitic mbali pa yozizira mlingo wa 10 ° C pa mphindi. Mawotchi katundu ntchito ndi wapakatikati pakati troostite ndi pearlite.

Perlite - ndi kuchuluka kwa mbewu ya ferrite ndi cementite, kumene kungakhale granular, kapena mawonekedwe mbale. Anapanga chifukwa cha kuwonongeka yosalala austenite pa yozizira 1s mlingo pa mphindi.

Beit troostite ndi - amatchula nyumba ndi kuzima, pamene sorbitol ndi perlite akhoza kupangidwa ndi tempering, annealing ndi normalizing mbali omwe amaonetsera mawonekedwe ndi kukula kwa mbewu.

Mmene annealing pa makamaka austenite kuwonongeka

Pafupifupi mitundu yonse ya annealing ndi normalization zochokera kusintha reciprocal wa austenite. Full ndi ganyu annealing ntchito doevtektoidnyh steels. Tsatanetsatane usavutike mu ng'anjo pamwamba mfundo yovuta Mac ₁ ndi Mac _3, motero. Mtundu woyamba amakhala ndi nthawi yaitali padzuwa, amene amaonetsetsa kutembenuka kwathunthu austenite-ferrite-austenite ndi pearlite. Otsatidwa ndi billets wosakwiya kuzirala mu ng'anjo. Pa linanena bungwe kupereka osakaniza wabwino wa ferrite ndi pearlite, popanda nkhawa mkati ndi pulasitiki wolimba. Zofewa annealing wochepa mphamvu-kwambiri, kokha chimasintha Kapangidwe ka perlite, ferrite kusiya pafupifupi sichinasinthe. Normalization zikusonyeza mlingo wapamwamba kuchepa kutentha Komabe, pulasitiki ndi zochepa dongosolo coarse pa kubwereketsa lapansi. Pakuti aloyi zitsulo ndi mpweya zili kwa 0,8 kwa 1.3% pamene utakhazikika mu normalization kuwola kumachitika kwa: austenite, pearlite, austenite-cementite.

mtundu wina wa mankhwala kutentha zomwe zachokera masinthidwe structural, ndi homogenisation. Ndi ntchito madera ambiri. Amatanthauza mtheradi kukwaniritsa boma coarse austenitic pa kutentha 1000-1200˚S ndi kupirira mu ng'anjo mu nthawi maola 15. njira Isothermal kupitiriza wosakwiya kuzirala, zomwe zimalimbikitsa equalization wa nyumba ya chitsulo.

isothermal annealing

Pakati pa izi njila yolimbikitsira zitsulo kuti zokambirana womvetsa ankamuona ngati isothermal wasinthika austenite. Komabe, aliyense wa iwo okha pa siteji makamaka ali makhalidwe. Mu zenizeni, kusintha kumachitika ndi kuchepa azilandira kutentha, liwiro amene amasankha zotsatira.

Njira imodzi imene wapafupi zinthu abwino - isothermal annealing. Kwenikweni ake komanso tichipeza mu Kutentha ndi kukhudzana ndi kugwa wathunthu wa nyumba zonse austenite lapansi. Kuzirala kuzindikira mu magawo angapo, amene kumathandiza kuti pang'onopang'ono, zambiri yaitali ndi thermally zambiri khola la kuwola ake.

1. Dontho mofulumira kutentha kwa mtengo pansipa 100 ° C kwa Mac ₁ Mfundo.
2. Kukakamizidwa posungira akwaniritsa mtengo (anaikidwa ng'anjo) kwa nthawi yaitali mpaka anamaliza wa mapangidwe magawo ferritic-pearlitic.
3. Yozizira mu akadali mpweya.

Njira applicable chifukwa steels aloyi, amene yodziwika ndi kukhalapo kwa austenite yotsalira boma m'firiji.

Yotsalira austenite ndi steels austenitic

Nthawi zina n'zotheka tsankho kuwola, pamene pali yotsalira austenite. Izi angayambe zinthu zotsatirazi:

1. kuzirala kwambiri mofulumira pamene kusokonezeka kwathunthu kumachitika. Ndi structural zikuluzikulu za bainite kapena martensite.
2. Mkulu mpweya zitsulo kapena otsika aloyi, zimene njira ndi kobvuta omwazika masinthidwe austenite. Pamafunika ntchito njira yapadera kutentha mankhwala, monga Mwachitsanzo, homogenization kapena isothermal annealing.

Pakuti high-- No ndondomeko anafotokozedwa ndi kusinthika. Alloying zitsulo ndi faifi tambala, manganese, chromium amalimbikitsa mapangidwe austenite monga chachikulu Chomangika amene sikutanthauza makhalidwe zina. steels Austenitic yodziwika ndi mphamvu yapamwamba, kukana dzimbiri ndi kutentha kukana, kutentha kukana ndi kukana kuti zinthu aukali ntchito yovuta.

Austenite - ndi dongosolo lomwe N'zosatheka kupanga palibe mkulu-kutentha Kutentha wachitsulo ndi zomwe zimafunika pafupifupi njira zake kutentha mankhwala kusintha katundu makina ndi processing.