T91 mkulu kuthamanga zitsulo chitoliro chitsimikizo khalidwe
T91 zitsulo ndi mtundu watsopano wazitsulo zosagwira kutentha kwa martensitic zopangidwa ndi labotale ya American National Elephant ridge ndi Metallurgical Materials Laboratory ya kampani yaku America combustion engineering. Pamaziko a chitsulo cha 9Cr1MoV, imachepetsa zomwe zili mu kaboni, imachepetsa zomwe zili mu sulfure ndi phosphorous, ndikuwonjezera anadium ndi niobium pang'ono pakupanga alloying.
Chitsulo chachitsulo cha T91 chopanda chitsulo chofanana ndi T91 chitsulo ndi x10crmovnnb91 ku Germany, hcm95 ku Japan ndi tuz10cdvnb0901 ku France.
Zomwe zili muzinthu
S ≤0.01
Ndi 0.20-0.50
Cr 8.00-9.50
Mo 0.85-1.05
V 0.18-0.25
Nb 0.06-0.10
N 0.03-0.07
Ndi ≤0.40
Chigawo chilichonse cha alloy mu T91 Steel chimagwira ntchito yolimbitsa yankho, kulimbikitsa kubalalitsidwa ndikuwongolera kukana kwa okosijeni ndi kukana dzimbiri kwachitsulo. Kusanthula kwapadera kuli motere.
①Mpweya ndiye chinthu chodziwikiratu kwambiri pakulimbitsa njira yolimba muzitsulo. Ndi kuchuluka kwa carbon, mphamvu yaifupi yachitsulo imawonjezeka ndipo pulasitiki ndi kulimba kumachepa. Kwa zitsulo za martensitic monga T91, kuwonjezeka kwa mpweya kumathandizira spheroidization ndi kuphatikiza kwa carbide, kufulumizitsa kugawidwa kwa zinthu za alloy ndikuchepetsa kutsekemera, kukana kwa dzimbiri ndi kukana kwa okosijeni kwachitsulo. Choncho, zitsulo zosagwira kutentha nthawi zambiri zimafuna kuchepetsa mpweya wa carbon, Komabe, ngati mpweya wa carbon ndi wotsika kwambiri, mphamvu yachitsulo idzachepetsedwa. Poyerekeza ndi chitsulo cha 12Cr1MoV, mpweya wa T91 wachitsulo umachepetsedwa ndi 20%, zomwe zimatsimikiziridwa ndi kuganizira mozama zomwe zili pamwambazi.
②Chitsulo cha T91 chili ndi nayitrogeni, ndipo ntchito ya nayitrogeni ikuwonetsedwa m'magawo awiri. Kumbali imodzi, imagwira ntchito yolimbitsa yankho lolimba. Kusungunuka kwa nayitrogeni muzitsulo kutentha kwa chipinda kumakhala kochepa kwambiri. Mu ndondomeko yowotcherera kutentha ndi positi weld kutentha kutentha, VN olimba njira ndi mpweya ndondomeko zidzachitika motsatizana mu pambuyo kuwotcherera kutentha anakhudzidwa zone ya T91 Zitsulo: kapangidwe austenitic chopangidwa mu kutentha anakhudzidwa zone pa kuwotcherera Kutentha kumawonjezera nayitrogeni okhutira chifukwa cha ndi kuvunda kwa VN, ndiyeno mlingo wa supersaturation mu dongosolo yachibadwa kutentha ukuwonjezeka, Mu wotsatira positi kuwotcherera kutentha mankhwala, pali zabwino VN mpweya, amene kumawonjezera microstructure bata ndi bwino chokhalitsa mphamvu ya kutentha bwanji zone. Komano, T91 chitsulo mulinso pang'ono A1. Nayitrojeni imatha kupanga A1N nayo. A1N imasungunuka mu matrix pokhapokha ikakhala pamwamba pa 1100 ℃ ndikuyambiranso kutentha pang'ono, komwe kumatha kulimbitsa kubalalitsidwa bwino.
③Kuonjezera chromium makamaka kumathandizira kukana kwa okosijeni komanso kukana kwa dzimbiri kwa chitsulo chosagwira kutentha. Pamene chromium zili zosakwana 5%, imayamba oxidize mwamphamvu pa 600 ℃, pamene chromium zili mpaka 5%, ali ndi zabwino makutidwe ndi okosijeni kukana. Chitsulo cha 12Cr1MoV chili ndi kukana kwa okosijeni wabwino pansi pa 580 ℃, ndipo kuya kwa dzimbiri ndi 0.05 mm / A. pa 600 ℃, ntchitoyo imayamba kuwonongeka, ndipo kuya kwa dzimbiri ndi 0.13 mm / A. Zomwe chromium ya T91 imatha kukulitsidwa mpaka pafupifupi 9% ndi kutentha kwautumiki kumatha kufika 650 ℃. Muyeso waukulu ndikusungunula chromium yambiri mu matrix.
④Vanadium ndi niobium ndi zinthu zamphamvu zopanga carbide. Pambuyo pake, amatha kupanga ma carbides abwino komanso okhazikika a alloy ndi kaboni, omwe ali ndi mphamvu yobalalika yolimbikitsa.
⑤ Molybdenum imawonjezedwa makamaka kuti ipititse patsogolo mphamvu yamafuta achitsulo ndikuchita gawo lolimbitsa njira yolimba.
Chithandizo chomaliza cha kutentha kwa T91 ndikuchiza + kutentha kwambiri. Kutentha kwa normalizing ndi 1040 ℃, nthawi yogwira si osachepera 10 min, kutentha kwa kutentha ndi 730 ~ 780 ℃, ndipo nthawi yogwira si yosachepera 1 h. The microstructure pambuyo pomaliza kutentha mankhwala ndi tempered martensite.
Mphamvu zolimba za T91 zitsulo pa kutentha kwa firiji ≥ 585 MPa, zokolola mphamvu kutentha kwa firiji ≥ 415 MPa, kuuma ≤ 250 Hb, elongation (chitsanzo chozungulira chozungulira ndi mtunda wa 50 mm gauge) ≥ 20%, mtengo wololera wopanikizika [ σ] 650 ℄ 30 MPa.
Malinga ndi njira yofananira ndi mpweya yomwe bungwe la International Welding Society limalimbikitsa, mpweya wofanana ndi T91 ndi wofanana.
Zitha kuwoneka kuti T91 ili ndi kuwotcherera koyipa.
Chitsulo cha T91 chimakhala ndi chizolowezi chachikulu cha mng'alu wozizira ndipo chimakonda kuchedwa kung'amba pansi pazifukwa zina. Choncho, olowa welded ayenera kutentha mkati maola 24 pambuyo kuwotcherera. The microstructure wa T91 pambuyo kuwotcherera ndi mbale ndi Mzere martensite, amene angasinthidwe mu tempered martensite pambuyo kutentha, ndi katundu wake ndi apamwamba kuposa mbale ndi strip martensite. Pamene tempering kutentha ndi otsika, tempering zotsatira si zoonekeratu, ndi weld zitsulo n'zosavuta ukalamba ndi embrittlement; Ngati kutentha kwatentha kwambiri (kupitilira mzere wa AC1), cholumikiziracho chikhoza kukhazikikanso ndikuumitsidwanso pakuzizira kotsatira. Pa nthawi yomweyo, monga tanenera kale mu pepalali, chikoka cha olowa kufewetsa wosanjikiza ayenera kuganiziridwa pa mtima kutentha kutentha. Nthawi zambiri, kutentha kwa T91 ndi 730 ~ 780 ℃.
The tempering zonse kutentha nthawi ya T91 pambuyo kuwotcherera sadzakhala zosakwana 1 h, kuti kuonetsetsa kusintha wathunthu dongosolo lake mu mtima martensite.
Pofuna kuchepetsa nkhawa yotsalira ya T91 zitsulo welded olowa, mlingo kuzirala ayenera kulamulidwa zosakwana 5 ℃ / min. Njira yowotcherera yachitsulo ya T91 ikuwonetsedwa pazithunzi 3.
Preheat 200 ~ 250 ℃; ② kuwotcherera, interlayer kutentha 200 ~ 300 ℃; ③ Kuzizira pambuyo kuwotcherera, ndi liwiro la 80 ~ 100 ℃ / h; ④ 100 ~ 150 ℃ kwa 1 h; ⑤ Kutentha kwa 730 ~ 780 ℃ kwa 1 h; ⑥ Kuzizira pamlingo wosaposa 5 ℃ / min.
T91 Chitsulo chimadalira pa mfundo ya alloying, makamaka kuwonjezera kachulukidwe kakang'ono ka zinthu monga niobium ndi vanadium. Kutentha kwake kwamphamvu komanso kukana kwa okosijeni kumakhala bwino kwambiri poyerekeza ndi chitsulo cha 12 cr1mov, koma kuwotcherera kwake sikukuyenda bwino.
Mayeso a pini akuwonetsa kuti chitsulo cha T91 chili ndi chizolowezi chachikulu cha mng'alu wozizira. Kusankha preheating 200 ~ 250 ℃ ndi interlayer kutentha 200 ~ 300 ℃ angathe kuteteza mng'alu ozizira.
T91 iyenera utakhazikika kwa 100 ~ 150 ℃ kwa 1 h pamaso positi kuwotcherera kutentha mankhwala; Kutentha kutentha 730 ~ 780 ℃, akugwira nthawi osachepera 1 h.
Njira yowotcherera yomwe ili pamwambapa yagwiritsidwa ntchito popanga ndi kupanga ma boiler a 200 MW ndi 300 MW, ndi zotsatira zokhutiritsa komanso phindu lalikulu lazachuma.
