T91 siab siab steel yeeb nkab kev ruaj ntseg
T91 steel yog ib yam tshiab ntawm martensitic tshav kub-resistant steel tsim los ntawm American National ntxhw ridge laboratory thiab Metallurgical Materials Laboratory ntawm American combustion engineering tuam txhab. Rau lub hauv paus ntawm 9Cr1MoV steel, nws txo cov ntsiab lus carbon, nruj me ntsis txwv cov ntsiab lus ntawm leej faj thiab phosphorus, thiab ntxiv ib qho me me ntawm vanadium thiab niobium rau alloying.
Qib steel ntawm T91 seamless steel yeeb nkab sib haum rau T91 steel yog x10crmovnnb91 hauv lub teb chaws Yelemees, hcm95 hauv Nyiv thiab tuz10cdvnb0901 hauv Fabkis.
Cov ntsiab lus
S ≤0.01
0.20-0.50 Nws
8.00-9.50 Nws
0.85-1.05 Nws
V 0.18-0.25 Nws
Ib 0.06-0.10
Nr 0.03-0.07
≤ 0.40
Txhua lub ntsiab lus alloy hauv T91 Steel plays lub luag haujlwm ntawm cov khoom siv ntxiv dag zog, dispersion ntxiv dag zog rau thiab txhim kho oxidation kuj thiab corrosion kuj ntawm cov hlau. Kev tsom xam tshwj xeeb yog raws li hauv qab no.
①Cov pa roj carbon monoxide yog qhov pom tseeb tshaj plaws ntawm kev daws teeb meem ntxiv dag zog hauv cov hlau. Nrog rau qhov nce ntawm cov ntsiab lus carbon, lub sij hawm luv luv lub zog ntawm steel nce thiab plasticity thiab toughness txo. Rau martensitic steel xws li T91, qhov nce ntawm cov ntsiab lus ntawm carbon yuav ua rau kom lub spheroidization thiab aggregation ntawm carbide, leeb lub redistribution ntawm alloy ntsiab thiab txo cov weldability, corrosion kuj thiab oxidation kuj ntawm hlau. Yog li ntawd, cov cua kub-resistant steel feem ntau xav txo cov ntsiab lus carbon, Txawm li cas los xij, yog tias cov ntsiab lus carbon tsawg dhau, lub zog ntawm cov hlau yuav raug txo. Piv nrog 12Cr1MoV steel, cov ntsiab lus carbon ntawm T91 steel yog txo los ntawm 20%, uas yog txiav txim siab los ntawm kev txiav txim siab los ntawm kev cuam tshuam ntawm cov ntsiab lus saum toj no.
②T91 steel muaj cov kab mob nitrogen, thiab lub luag haujlwm ntawm nitrogen yog xav txog ob yam. Ntawm qhov tod tes, nws plays lub luag haujlwm ntawm kev daws teeb meem ntxiv dag zog. Lub solubility ntawm nitrogen nyob rau hauv steel nyob rau hauv chav tsev kub yog heev me me. Nyob rau hauv cov txheej txheem ntawm vuam cua sov thiab tom qab vuam cua sov kho, VN khoom tov thiab nag lossis daus txheej txheem yuav tshwm sim nyob rau hauv lub post weld tshav kub cuam tshuam cheeb tsam ntawm T91 Steel: lub austenitic qauv tsim nyob rau hauv lub tshav kub cuam tshuam cheeb tsam thaum vuam cua sov tsub kom cov nitrogen cov ntsiab lus vim Lub dissolution ntawm VN, thiab tom qab ntawd lub degree ntawm supersaturation nyob rau hauv ib txwm kub qauv nce, nyob rau hauv lub tom ntej no ncej weld tshav kub kev kho mob, muaj zoo VN nag lossis daus, uas ua rau kom lub microstructure stability thiab txhim kho lub zog ntev ntawm lub tshav kub cuam tshuam cheeb tsam. Ntawm qhov tod tes, T91 steel kuj muaj me me ntawm A1. Nitrogen tuaj yeem tsim A1N nrog nws. A1N yog yaj mus rau hauv lub matrix tsuas yog thaum nws siab tshaj 1100 ℃ thiab precipitates dua nyob rau hauv ib tug qis kub, uas yuav ua si ib tug zoo dispersion ntxiv zog.
③Ntxiv chromium yog tsuas yog los txhim kho cov oxidation tsis kam thiab corrosion kuj ntawm tshav kub-resistant steel. Thaum cov ntsiab lus chromium tsawg dua 5%, nws pib oxidize hnyav ntawm 600 ℃, thaum cov ntsiab lus chromium nce txog 5%, nws muaj oxidation zoo. 12Cr1MoV steel muaj qhov zoo oxidation tsis kam qis dua 580 ℃, thiab qhov tob corrosion yog 0.05 mm / A. ntawm 600 ℃, qhov kev ua tau zoo pib deteriorate, thiab corrosion qhov tob yog 0.13 mm / A. Cov ntsiab lus chromium ntawm T91 tuaj yeem nce mus txog li. 9% thiab qhov kev pabcuam kub tuaj yeem ncav cuag 650 ℃. Lub ntsiab ntsuas yog kom yaj ntau chromium hauv matrix.
④Vanadium thiab niobium yog cov muaj zog carbide tsim cov ntsiab lus. Tom qab ntxiv, lawv tuaj yeem tsim cov hlau zoo thiab ruaj khov carbides nrog cov pa roj carbon monoxide, uas muaj cov nyhuv dispersion muaj zog.
⑤ Molybdenum feem ntau yog ntxiv los txhim kho cov thermal zog ntawm cov hlau thiab ua lub luag haujlwm ntawm cov khoom siv ntxiv dag zog.
Kev kho cua sov kawg ntawm T91 yog normalizing + kub tempering. Lub normalizing kub yog 1040 ℃, lub sij hawm tuav tsis pub tsawg tshaj 10 min, tempering kub yog 730 ~ 780 ℃, thiab tuav lub sij hawm tsis tsawg tshaj li 1 h. Lub microstructure tom qab kev kho cua sov kawg yog tempered martensite.
Tensile lub zog ntawm T91 steel ntawm chav tsev kub ≥ 585 MPa, yield zog ntawm chav tsev kub ≥ 415 MPa, hardness ≤ 250 Hb, elongation (tus qauv ncig nrog 50 hli ntsuas qhov nrug) ≥ 20%, tso cai rau kev ntxhov siab tus nqi [ σ] 650 ℃ = 30 MPa.
Raws li cov qauv sib npaug ntawm cov pa roj carbon monoxide tau pom zoo los ntawm thoob ntiaj teb vuam kev sib raug zoo, cov pa roj carbon sib npaug ntawm T91 yog
Nws tuaj yeem pom tias T91 muaj qhov tsis zoo weldability.
T91 steel muaj qhov xav tau loj ntawm cov kab mob khaub thuas thiab yog qhov ua rau qeeb qeeb hauv qee yam mob. Yog li ntawd, lub welded sib koom yuav tsum tau tempered nyob rau hauv 24 teev tom qab vuam. Lub microstructure ntawm T91 tom qab vuam yog phaj thiab strip martensite, uas tuaj yeem hloov mus rau hauv tempered martensite tom qab tempering, thiab nws cov khoom zoo dua rau phaj thiab strip martensite. Thaum lub tempering kub yog tsawg, cov nyhuv tempering tsis pom tseeb, thiab cov hlau vuam yog yooj yim rau hnub nyoog thiab embrittlement; Yog tias qhov kub thiab txias siab dhau (dhau AC1 kab), qhov sib koom ua ke tuaj yeem ua rau austenitized dua thiab tawv dua hauv cov txheej txheem txias tom ntej. Nyob rau tib lub sijhawm, raws li tau hais ua ntej hauv daim ntawv no, kev cuam tshuam ntawm kev sib koom ua ke yuav tsum tau xav txog hauv kev txiav txim siab ntawm tempering kub. Feem ntau hais lus, qhov kub thiab txias ntawm T91 yog 730 ~ 780 ℃.
Lub sijhawm ntsuas kub tsis tu ncua ntawm T91 tom qab vuam yuav tsum tsis pub tsawg dua 1 h, txhawm rau ua kom tiav kev hloov pauv ntawm nws cov qauv rau hauv tempered martensite.
Txhawm rau txo qhov kev ntxhov siab ntawm T91 steel welded sib koom ua ke, qhov cua txias yuav tsum tau tswj tsawg dua 5 ℃ / min. Cov txheej txheem vuam ntawm T91 steel tuaj yeem pom hauv daim duab 3.
Preheat 200 ~ 250 ℃; ② Vuam, interlayer kub 200 ~ 300 ℃; ③ Txias tom qab vuam, nrog kev ceev ntawm 80 ~ 100 ℃ / h; ④ 100 ~ 150 ℃ rau 1 h; ⑤ Tempering ntawm 730 ~ 780 ℃ rau 1 h; ⑥ Txias ntawm tus nqi tsis ntau tshaj 5 ℃ / min.
T91 Steel tso siab rau lub hauv paus ntsiab lus ntawm alloying, tshwj xeeb tshaj yog ntxiv ib qho me me ntawm cov kab mob xws li niobium thiab vanadium. Nws qhov kub thiab txias zog thiab oxidation kuj zoo heev piv nrog 12 cr1mov hlau, tab sis nws cov vuam kev ua tau zoo tsis zoo.
Kev ntsuas tus pin qhia tau hais tias T91 steel muaj qhov nyiam ntawm qhov txias txias. Kev xaiv preheating 200 ~ 250 ℃ thiab interlayer kub 200 ~ 300 ℃ tuaj yeem tiv thaiv qhov txias txias.
T91 yuav tsum tau txias rau 100 ~ 150 ℃ rau 1 h ua ntej kev kho cua sov tom qab vuam; Tempering kub 730 ~ 780 ℃, tuav lub sij hawm tsis pub tsawg tshaj 1 h.
Cov txheej txheem vuam saum toj no tau siv rau kev tsim khoom thiab kev ua haujlwm ntawm 200 MW thiab 300 MW boilers, nrog cov txiaj ntsig zoo thiab cov txiaj ntsig zoo ntawm kev lag luam.
