Hydrogen Cov ntsiab lus tswj, kev kho cua sov txheej txheem tseem ceeb ntawm Titanium yeeb nkab fittings

Hydrogen yog lub hauv paus teeb meem impurity uas txwv cov kev pab cuam kev ntseeg siab ntawmtitanium yeeb nkab fittings. Kev nqus dej ntau dhau tau yooj yim tsim cov titanium hydride nkig, inducing hydrogen embrittlement cracking. Kev kho cua sov yog cov txheej txheem tseem ceeb los tswj cov qauv metallographic ntawm cov kav dej, tshem tawm cov hydrogen ntau dhau, thiab sib npaug ntawm cov khoom siv kho tshuab.

 

 

1. Kev puas tsuaj los ntawm Hydrogen ntau dhau

Titanium nkag tau hydrogen ntawm qhov kub siab tshaj 300 degree. Supersaturated hydrogen precipitates li brittle titanium hydride, uas nthuav nyob rau hauv ntim thiab tsim kev ntxhov siab nyob rau hauv, ua rau microcracks nyob rau hauv lub puab phab ntsa, welds thiab kev nyuaj siab cheeb tsam, thiab thaum kawg ua rau hydrogen embrittlement puas.

 

Hydrogen cov ntsiab lus tswj txwv: industrial titanium / Gr5: Tsawg dua lossis sib npaug li 0.015 wt%; aerospace yeeb nkab fittings: Tsawg dua los yog sib npaug rau 0.010 wt%; hydrogen zog thiab sib sib zog nqus - hiav txwv titanium kav: Tsawg dua los yog sib npaug rau 0.008 wt%.

 

2. Kev tswj hwm ntawm Hydrogen Absorption nyob rau hauv tag nrho cov txheej txheem

• Cov khoom siv raw tswj: Txais siv lub tshuab nqus tsev consumable arc melting billets, rov- tshuaj xyuas cov ntsiab lus hydrogen ntawm cov khoom tuaj, thiab tswj cov dej stains, roj stains thiab xeb ntawm cov khoom siv raw los thaiv cov hydrogen hauv qhov chaw.
• Kev tiv thaiv thaum tsim thiab ua

Pickling: Hloov mus rau nitric acid- cov mis tsis muaj hydrofluoric acid, txo lub sij hawm ntub dej, thiab ntxuav tag nrho thiab qhuav tom qab pickling kom tsis txhob muaj cov kua qaub seem hauv qab -induced hydrogen permeation.

Rolling thiab txias kos duab: Siv hydrogen - roj lubricating dawb, nruj me ntsis tswj kev ua pob thiab khawb kom tsis txhob muaj kev puas tsuaj rau titanium tiv thaiv zaj duab xis thiab tom qab nqus hydrogen.

• Kev tswj cov dej noo thaum kho cua sov: Qhuav lub cub tawg lub cev thiab xyuas kom nws airtightness; Cov dej vapor thiab cov ntsiab lus oxygen hauv argon rauv yuav tsum tsawg dua lossis sib npaug li 10 ppm. Degrease workpieces nrog acetone thiab anhydrous ethanol, thiab txwv tsis pub siv halogenated hydrocarbons thiab methanol kom tsis txhob hydrogen evolution thaum cua sov.

 

3. Kev Kho Kom Zoo Rau Hydrogen ntau dhau

• Lub tshuab nqus tsev siab -kub annealing dehydrogenation yog siv rau cov kav dej titanium nrog hydrogen ntau dhau: nyob rau hauv lub tshuab nqus tsev<0.066 Pa, hold at 540–760°C for 2–4 hours followed by furnace slow cooling.
• Kev kub siab txhawb nqa hydrogen diffusion thiab nag lossis daus kom tau raws li tus qauv, uas yog ib qho kev rov ua dua tshiab rau aerospace titanium kav.

 

 

1. Kev lag luam ntshiab Titanium Gr1 thiab Gr2

• Kev nyuaj siab nyem annealing: Tuav ntawm 520-580℃rau 60-120 feeb, ua raws li lub tshuab nqus tsev / argon qeeb txias. Nws tshem tawm cov kev ntxhov siab nyob hauv kev ua haujlwm, zam kev ntxhov siab corrosion-induced hydrogen absorption cracking, tswj lub zog thiab precision, thiab yog siv rau tshuaj thiab dej thiab cov kav dej.
• Tag nrho annealing: Tuav ntawm 650-720℃rau 90-180 feeb tom qab cua txias. Nws tshem tawm kev ua hauj lwm hardening, refines equiaxed nplej, txhim kho plasticity, yooj yim rau cov yeeb nkab dabtsi yog khoov thiab flaring, thiab qhov xwm txheej tshem tawm cov kab absorbed hydrogen.

 

2. Gr5 Titanium Alloy

• Pa puv annealing: Tuav ntawm 800-850℃rau 1-2 teev tom qab cua txias kom tau ib qho equiaxed + zoo microstructure nrog sib npaug zog thiab toughness thiab hydrogen embrittlement tsis kam, feem ntau yog siv rau cov roj thiab roj thiab cov kav dej kub pauv.
• Kev kho mob thiab kev laus: Cov kev kho mob ntawm 920-950℃tom qab dej quenching, ces laus ntawm 480-530℃rau 3-5 teev, muaj zog tshaj 900 MPa. Kev kho lub tshuab nqus tsev vacuum ua tiav ib txhij ntxiv dag zog thiab tswj hydrogen / dehydrogenation.
• Muab ob npaug rau annealing: Cua txias ntawm 920℃+ tuav thiab qeeb txias ntawm 700 degree, uas inhibits hydride tsim thiab yog haum rau sib sib zog nqus - hiav txwv thiab hydrogen zog siab - siab yeeb nkab fittings.

 

3. Kev tiv thaiv oxidation thiab hydrogen absorption thaum kho cua sov

• Ua ntej lub tshuab nqus tsev kub kho siab tshaj 540 degree; Cov cua sov zoo tib yam tsuas yog siv rau qis- cov kav dej kawg, thiab cov oxide txheej yuav tsum tau muab tshem tawm los ntawm kev ua haujlwm tom qab.
• Cov pa roj carbon steel yuav tsum tsis txhob muab sib xyaw rau hauv qhov cub kom tsis txhob galvanic corrosion thiab hydrogen absorption embrittlement ntawm titanium cov ntaub ntawv los ntawm hlau impurities.

 

 

1. Mechanical Properties

• Lub zog tensile ntawm ntshiab titanium yog 350-500 MPa, thiab cov annealed Gr5 yog 830-900 MPa, nrog ib tug ceev tsuas yog 60% ntawm cov hlau, ua rau lub teeb yuag kav. Aged Gr5 muaj zog tshaj 1000 MPa, haum rau aerospace siab - cov kav dej.
• Titanium cov kav dej uas tsim nyog cov ntsiab lus hydrogen thiab cov txheej txheem annealing muaj qhov elongation tus nqi ntau dua lossis sib npaug li 15%, ua kom yooj yim khoov txias; qhov nplua -cov qauv ua tau zoo muab kev qaug zog ua haujlwm, haum rau cov khoom siv hluav taws xob. Cov hydrogen ntau dhau yuav txo cov plasticity thiab ua kom yooj yim tawg thaum cov yeeb nkab dabtsi yog khoov.

 

2. Corrosion thiab Hydrogen Resistance

• Lub nto TiO₂ passive zaj duab xis yog resistant rau acid, alkali thiab seawater corrosion, nrog ib tug kev pab cuam lub neej 5-10 npaug ntawm carbon hlau. Ib zaj duab xis tsis zoo tuaj yeem thaiv kev nkag mus rau hydrogen.
• Cov ntsiab lus hydrogen Tsawg dua lossis sib npaug li 0.015% tuaj yeem zam qhov kub thiab nruab nrab - tsis tshua muaj siab hydrogen embrittlement; Cov hydrogen ntau dhau tuaj yeem tsim cov hydrides nyob rau hauv kev ntxhov siab corrosion, ua rau tam sim ntawd brittle puas. Siab -siab tob- hiav txwv thiab hydrogen zog pipelines yuav tsum nruj hydrogen cov ntsiab lus tswj.

 

3. Lub cev muaj zog

Tsis yog- sib nqus, tsis tshua muaj thermal expansion coefficient, ruaj khov microstructure ntawm 350℃siab kub, thiab zoo low- kub toughness, haum rau cryogenic pipelines tshwj xeeb.

 

 

Yog xav paub ntxiv txog cov kav dej titaium, xa lus rau peb ntawm Email:Sam.Rui@bjrh-titanium.com