Dab tsi yog npib tsib xee-Raws li cov alloys nyiam rau kev ua haujlwm hnyav hauv kev lag luam tshuaj?

1. Hastelloy C - series alloys (kev daws teeb meem - ntxiv dag zog rau npib tsib xee - molybdenum - chromium alloys)

Cov qhab niaHastelloy C276, Hastelloy C22, Hastelloy C4

Core zoo: Cov alloys muaj cov ntsiab lus siab ntawm Mo (15% - 16%) thiab Cr (15% - 22}%), nrog rau me me ntawm W ntxiv. Lawv muaj kev tiv thaiv zoo heevpitting corrosion, crevice corrosion, thiab intergranular corrosion, tshwj xeeb tshaj yog rau cov tshuaj chloride - uas muaj cov xov xwm thiab oxidizing - txo cov acids sib xyaw (xws li sulfuric acid + hydrochloric acid, sulfuric acid + nitric acid). Hastelloy C276 yog lub npe hu ua "universal corrosion - } resistant alloy" thiab tuaj yeem tiv taus corrosion los ntawm cov chlorine ntub dej, hypochlorite, thiab ntau yam organic acids.

Tej kev siv: Chemical reactors, heat exchangers, pipelines, valves in environments with concentrated hydrochloric acid, sulfuric acid, thiab chloride ions.

2. Hastelloy B - series alloys (nickel - molybdenum alloys)

Cov qhab nia: Hastelloy B2, Hastelloy B3

Core zoo: Cov ntsiab lus Mo siab (26% - 28%) muab rau lawvzoo heev tiv thaiv kom txhob acids, tshwj xeeb tshaj yog hydrochloric acid ntawm tag nrho cov concentrations thiab kub (tshwj tsis yog oxidizing impurities xws li ferric ions thiab cupric ions). Lawv yuav luag tiv thaiv corrosion nyob rau hauv dilute thiab concentrated hydrochloric acid nyob rau hauv chav tsev kub rau nruab nrab kub.Kev txwv: Tsis zoo rau oxidizing media; yooj yim corroded nyob rau hauv nitric acid los yog tov acids nrog oxidants.

Tej kev siv: Khoom siv rau kev tuav siab - purity hydrochloric acid, acetic acid, thiab phosphoric acid hauv kev lag luam tshuaj.

3. Inconel 625 (kev daws teeb meem - ntxiv dag zog rau npib tsib xee - chromium - niobium alloy)

Core zoo: Muaj Cr (21%), Mo (9%), thiab Nb (3.6%). Nb tsim cov theem ruaj khov carbide, uas txhim kho ob qho tib si corrosion kuj thiab siab - kub zog. Nws muaj kev tiv thaiv zoo rau pitting corrosion thiab crevice corrosion hauv chloride media, thiab tuaj yeem tiv taus corrosion los ntawm seawater, ntsev tsuag, thiab alkaline daws. Nws kuj muaj kev qaug zog zoo heev thiab haum rau siab - kub corrosive tej yam kev mob (txog 980℃).

Tej kev siv: Chemical process pipelines, flue gas desulfurization systems (FGD), thiab marine chemical equipment.

4. Monel 400 (nickel - tooj liab alloy)

Core zoo: Muaj 63% Ni thiab 28% Cu, nrog kev ua haujlwm zoo rauhydrofluoric acid, dej hiav txwv, thiab alkaline media. Nws kuj tseem tiv taus corrosion los ntawm tsis yog - oxidizing acids xws li sulfuric acid thiab hydrochloric acid ntawm qhov kub thiab txias.

Tej kev siv: Cov khoom siv los tuav cov tshuaj hydrofluoric acid, dej ntsev, thiab cov tshuaj ammonia hauv kev lag luam tshuaj.

Cov ntsiab lus ntawm kev xaiv

Rauoxidizing - txo kev sib xyaw corrosive media: Ua ntej Hastelloy C276/C22.

Rauntshiab txo cov kua qaub (hydrochloric acid) ib puag ncig: Xaiv Hastelloy B2/B3.

Rausiab - kub + corrosive + mechanical stress integrated conditions: Xaiv Inconel 625.

Rauhydrofluoric acid thiab alkaline media: Monel 400 yog qhov kev xaiv zoo tshaj plaws.

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Dab tsi yog qhov yuav tsum tau ua rau daim ntawv thov ntawm Nickel - Raws li Alloys hauv Nuclear Reactor Cheebtsam?

Nickel - raws li alloys yog dav siv nyob rau hauv nuclear reactor Cheebtsam (nrog rau cov dej pressurized reactors, boiling dej reactors, thiab ceev neutron reactors) vim lawv zoo heev siab - kub zog, corrosion kuj, thiab hluav taws xob tsis kam. Lawv daim ntawv thov yuav tsum nruj, thiabyam tseem ceebyog raws li nram no:

1. Corrosion kuj yuav tsum tau

Nuclear reactor coolant systems (tshwj xeeb tshaj yog cov dej siab reactors) siv siab - kub thiab siab - dej siab (150 - 350 degree, 10 - 15 MPa) raws li cov coolant, thiab cov dej muaj ib tug kab nyob rau hauv cov pa oxygen, hydrogen, thiab chloride ions. Nickel - raws li alloys yuav tsum ua raws li cov qauv hauv qab no corrosion:

Tiv thaiv kom tsis txhob muaj corrosion: Tus nqi corrosion nyob rau hauv reactor coolant yuav tsum tsawg tshaj li 0.01 hli / xyoo kom ntseeg tau ntev - lub neej kev pab cuam (feem ntau ntau tshaj 40 xyoo).

Kev tiv thaiv rau localized corrosion: Yuav tsum muaj kev tiv thaiv zoo heev rau pitting corrosion, crevice corrosion, thiab kev nyuaj siab corrosion cracking (SCC). Kev ntxhov siab corrosion tshwm sim los ntawm cov tshuaj chloride ions thiab kub siab / dej siab yog qhov ua tsis tau zoo ntawm cov khoom siv reactor, yog li cov alloys xws li Inconel 690 thiab Hastelloy X raug xaiv rau lawv cov ntsiab lus Cr siab (ntau tshaj 20%) los tsim cov zaj duab xis tuab.

Ua haujlwm rau intergranular corrosion: Tsis txhob hnov qab txog cov hlau (cov nag lossis daus ntawm Cr - nplua nuj carbides ntawm cov ciam teb ua rau Cr depletion nyob rau hauv cov cheeb tsam uas nyob ib sab). Piv txwv li, Inconel 690 muaj cov ntsiab lus carbon tsawg (< 0.03%) and is stabilized with Ti/Nb to prevent intergranular corrosion.

2. High - kub mechanical kev ua tau zoo yuav tsum

Nuclear reactor Cheebtsam (xws li lub tshuab hluav taws xob lub tshuab hluav taws xob, lub siab lub nkoj, thiab kev tswj cov pas nrig tshuab) ua haujlwm nyob rau hauv siab - kub thiab siab - siab rau lub sijhawm ntev, yog li nickel - raws li cov alloys yuav tsum muaj:

High tensile lub zog thiab yield zog: Ntawm qhov kub ntawm kev khiav hauj lwm (300 - 650 degree), lub zog tawm los yuav tsum tau khaws cia ntawm ntau tshaj 200 MPa los tiv thaiv lub siab ntawm cov dej txias thiab cov qauv kev ntxhov siab.

Zoo heev creep kuj: Creep deformation yog daim ntawv tseem ceeb ntawm kev ua tsis tiav ntawm cov khoom nyob rau hauv ntev - lub sij hawm siab - kub ntxhov siab. Nickel - raws li cov alloys (piv txwv li, Inconel 718, Waspaloy) tso siab rau nag lossis daus ntawm 'thiab' theem los tiv thaiv kev txav mus los, thiab lawv cov creep rupture lub neej ntawm 600℃thiab 100 MPa yuav tsum ntau tshaj 10,000 teev.

Kev qaug zog zoo: Reactor Cheebtsam yog raug rau cyclic kev nyuaj siab tshwm sim los ntawm pib - up, shutdown, thiab load hloov. Lub alloy yuav tsum muaj lub zog qaug zog siab kom tsis txhob qaug zog tawg.

3. Radiation kuj yuav tsum tau

Nuclear reactor cores yog nyob rau hauv ib puag ncig hluav taws xob muaj zog (neutron radiation, gamma radiation). Nickel - raws li alloys yuav tsum tiv taushluav taws xob - induced degradation:

Resistance rau hluav taws xob embrittlement: Cov hluav taws xob neutron yuav ua rau muaj qhov tsis xws luag xws li qhov chaw ua haujlwm thiab kev tsis sib haum xeeb hauv cov hlau nplaum, uas ua rau kom muaj zog ntxiv thiab txo qhov tawv (embrittlement). Cov hlau yuav tsum muaj cov ntsiab lus tsawg ntawm impurity ntsiab (xws li P, S) thiab ua kom zoo dua los ntawm kev kho cua sov kom txo tau qhov rhiab heev rau hluav taws xob embrittlement.

Kev tiv thaiv hluav taws xob - induced o: Ntev - lub sij hawm neutron hluav taws xob yuav ua rau atomic hloov chaw, ua rau lub ntim expansion ntawm cov hlau (o). Rau ceev neutron reactor Cheebtsam, qhov o tus nqi ntawm cov hlau ntawm ib tug neutron fluence ntawm 10²² n / cm² yuav tsum tsawg tshaj li 5% los xyuas kom meej cov qauv kev ncaj ncees.

4. Cov txheej txheem kev ua tau zoo thiab kev ntseeg tau

Weldability: Feem ntau cov reactor Cheebtsam yog sib dhos los ntawm vuam. Cov hlau yuav tsum muaj qhov zoo weldability, thiab cov vuam sib txuas yuav tsum muaj tib yam corrosion kuj thiab kev ua haujlwm zoo li cov hlau hauv paus. Piv txwv li, Inconel 690 yog dav siv los ua lub tshuab hluav taws xob cov raj vim nws cov weldability zoo heev thiab tsis muaj ncej - weld tshav kub kho.

Stability ntawm tshuaj muaj pes tsawg leeg: nruj me ntsis tswj cov ntsiab lus ntawm kab kawm (xws li, B, Cd, uas yog neutron absorbers) kom tsis txhob cuam tshuam cov neutron flux tis nyob rau hauv lub reactor core. Cov ntsiab lus ntawm cov khoom tsis zoo (xws li Pb, Bi) yuav tsum tsawg dua 10 ppm los tiv thaiv kub corrosion.

Nickel Alloys ua haujlwm hauv kev lag luam tshuaj