Kev sib xyaw ua ke ntawm Superalloys

Kev sib xyaw ua ke ntawm Superalloys

(1) Cov yam ntxwv ntawm kev sib txhuam ntawm cov superalloys tuaj yeem muab faib ua peb pawg: nickel puag, hlau puag thiab cobalt puag. Lawv muaj cov khoom siv kho tshuab zoo, tiv taus oxidation thiab tiv taus corrosion ntawm qhov kub siab. Nickel puag alloy yog qhov siv dav tshaj plaws hauv kev tsim khoom siv.

Cov superalloy muaj ntau Cr, thiab zaj duab xis Cr2O3 oxide uas nyuaj rau tshem tawm yog tsim rau ntawm qhov chaw thaum lub sijhawm cua sov. Cov superalloys nickel muaj Al thiab Ti, uas yooj yim rau oxidize thaum cua sov. Yog li ntawd, txhawm rau tiv thaiv lossis txo qhov oxidation ntawm superalloys thaum lub sijhawm cua sov thiab tshem tawm cov zaj duab xis oxide yog qhov teeb meem tseem ceeb thaum lub sijhawm brazing. Raws li borax lossis boric acid hauv cov flux tuaj yeem ua rau xeb ntawm cov hlau hauv paus ntawm qhov kub brazing, cov boron precipitated tom qab cov tshuaj tiv thaiv tuaj yeem nkag mus rau hauv cov hlau hauv paus, ua rau muaj kev nkag mus rau hauv intergranular. Rau cov hlau nickel hauv paus uas muaj cov ntsiab lus Al thiab Ti siab, qib nqus tsev hauv lub xeev kub yuav tsum tsis pub tsawg dua 10-2 ~ 10-3pa thaum lub sijhawm brazing kom tsis txhob oxidation ntawm qhov chaw alloy thaum lub sijhawm cua sov.

Rau cov hlau nickel uas muaj zog thiab cov hlau uas muaj zog nag lossis daus, qhov kub ntawm kev sib txhuam yuav tsum sib xws nrog qhov kub ntawm kev kho cov tshuaj kom ntseeg tau tias cov khoom sib xyaw yaj tag nrho. Qhov kub ntawm kev sib txhuam qis dhau, thiab cov khoom sib xyaw tsis tuaj yeem yaj tag nrho; Yog tias qhov kub ntawm kev sib txhuam siab dhau, cov hlau puag yuav loj hlob, thiab cov khoom siv yuav tsis rov qab zoo txawm tias tom qab kev kho cua sov. Qhov kub ntawm cov khoom sib xyaw ua los ntawm cov hlau puag yog siab, uas feem ntau yuav tsis cuam tshuam rau cov khoom siv vim qhov kub ntawm kev sib txhuam siab dhau.

Qee cov hlau nickel-base superalloys, tshwj xeeb tshaj yog cov hlau uas muaj zog los ntawm cov nag lossis daus, muaj qhov nyiam tawg ntawm kev ntxhov siab. Ua ntej brazing, kev ntxhov siab uas tsim nyob rau hauv cov txheej txheem yuav tsum tau tshem tawm tag nrho, thiab kev ntxhov siab thermal yuav tsum tau txo qis thaum lub sijhawm brazing.

(2) Cov khoom siv brazing nickel puag alloy tuaj yeem brazed nrog nyiaj puag, tooj liab ntshiab, nickel puag thiab nquag solder. Thaum qhov kub ua haujlwm ntawm qhov sib koom ua ke tsis siab, cov khoom siv nyiaj raws li tuaj yeem siv. Muaj ntau hom nyiaj raws li solders. Txhawm rau kom txo qhov kev ntxhov siab sab hauv thaum lub sijhawm brazing cua sov, nws yog qhov zoo tshaj plaws los xaiv cov solder nrog qhov kub yaj qis. Fb101 flux tuaj yeem siv rau brazing nrog nyiaj puag filler hlau. Fb102 flux yog siv rau brazing precipitation strengthened superalloy nrog cov ntsiab lus txhuas siab tshaj plaws, thiab 10% ~ 20% sodium silicate lossis txhuas flux (xws li fb201) ntxiv. Thaum qhov kub brazing tshaj 900 ℃, fb105 flux yuav tsum tau xaiv.

Thaum brazing hauv lub tshuab nqus tsev lossis huab cua tiv thaiv, tooj liab ntshiab tuaj yeem siv ua hlau brazing filler. Qhov kub brazing yog 1100 ~ 1150 ℃, thiab qhov sib koom ua ke yuav tsis tsim kev ntxhov siab, tab sis qhov kub ua haujlwm yuav tsum tsis pub tshaj 400 ℃.

Cov hlau nplaum nickel uas siv rau kev sib xyaw ua ke yog cov hlau nplaum uas siv ntau tshaj plaws hauv Superalloys vim nws qhov kev ua haujlwm kub zoo thiab tsis muaj kev ntxhov siab thaum lub sijhawm sib xyaw. Cov ntsiab lus tseem ceeb hauv cov hlau nplaum nickel yog Cr, Si, B, thiab me me ntawm cov hlau nplaum kuj muaj Fe, W, thiab lwm yam. Piv nrog ni-cr-si-b, b-ni68crwb cov hlau nplaum tuaj yeem txo qhov kev nkag mus rau hauv cov hlau nplaum thiab ua rau lub sijhawm kub yaj ntxiv. Nws yog cov hlau nplaum rau kev sib xyaw ua ke rau qhov kub siab ua haujlwm thiab cov hniav turbine. Txawm li cas los xij, qhov fluidity ntawm W-muaj cov hlau nplaum ua rau qhov tsis zoo thiab qhov sib txawv ntawm qhov sib koom ua ke nyuaj rau tswj.

Cov hlau uas siv rau kev sib xyaw ua ke tsis muaj Si thiab muaj kev tiv thaiv oxidation zoo heev thiab tiv thaiv vulcanization. Qhov kub ntawm kev sib xyaw ua ke tuaj yeem xaiv tau los ntawm 1150 ℃ txog 1218 ℃ raws li hom solder. Tom qab sib xyaw ua ke, qhov sib koom ua ke nrog cov khoom zoo ib yam li cov hlau hauv paus tuaj yeem tau txais tom qab 1066 ℃ kev kho diffusion.

(3) Cov txheej txheem brazing nickel base alloy tuaj yeem siv brazing hauv lub cub tawg tiv thaiv huab cua, lub tshuab nqus tsev brazing thiab kev sib txuas kua dej ib ntus. Ua ntej brazing, qhov chaw yuav tsum tau degreased thiab oxide tshem tawm los ntawm sandpaper polishing, felt log polishing, acetone scrubbing thiab tshuaj ntxuav. Thaum xaiv cov txheej txheem brazing, nws yuav tsum tau sau tseg tias qhov kub thiab txias yuav tsum tsis txhob siab dhau thiab lub sijhawm brazing yuav tsum luv kom tsis txhob muaj tshuaj lom neeg muaj zog ntawm cov flux thiab cov hlau hauv paus. Txhawm rau tiv thaiv cov hlau hauv paus los ntawm kev tawg, cov khoom ua tiav txias yuav tsum tau txo kev ntxhov siab ua ntej welding, thiab qhov cua sov vuam yuav tsum sib xws li sai tau. Rau cov superalloys uas muaj zog nag lossis daus, cov khoom yuav tsum raug kho cov kua khov ua ntej, tom qab ntawd brazed ntawm qhov kub me ntsis siab dua li kev kho kom muaj zog laus, thiab thaum kawg kev kho kom laus.

1) Kev sib txhuam hauv lub cub tawg tiv thaiv huab cua, kev sib txhuam hauv lub cub tawg tiv thaiv huab cua xav tau cov roj tiv thaiv uas muaj qhov huv si. Rau cov superalloys nrog w (AL) thiab w (TI) tsawg dua 0.5%, qhov dew point yuav tsum qis dua -54 ℃ thaum siv hydrogen lossis argon. Thaum cov ntsiab lus ntawm Al thiab Ti nce ntxiv, qhov chaw ntawm cov hlau tseem oxidizes thaum cua sov. Cov kev ntsuas hauv qab no yuav tsum tau ua; Ntxiv me ntsis ntawm cov kua nplaum (xws li fb105) thiab tshem tawm cov zaj duab xis oxide nrog cov kua nplaum; 0.025 ~ 0.038mm tuab txheej yog plated rau ntawm qhov chaw ntawm cov khoom; Tshuaj tsuag cov kua nplaum rau ntawm qhov chaw ntawm cov khoom siv uas yuav tsum tau brazed ua ntej; Ntxiv me ntsis ntawm cov kua nplaum roj, xws li boron trifluoride.

2) Lub tshuab nqus tsev brazing siv lub tshuab nqus tsev brazing dav dav kom tau txais kev tiv thaiv zoo dua thiab zoo brazing. Saib lub rooj 15 rau cov khoom siv kho tshuab ntawm cov pob qij txha nickel puag superalloy. Rau cov superalloys nrog w (AL) thiab w (TI) tsawg dua 4%, nws zoo dua rau electroplate ib txheej ntawm 0.01 ~ 0.015mm nickel ntawm qhov chaw, txawm hais tias qhov ntub ntawm solder tuaj yeem ua kom ntseeg tau yam tsis muaj kev kho tshwj xeeb. Thaum w (AL) thiab w (TI) tshaj 4%, qhov tuab ntawm nickel txheej yuav tsum yog 0.020.03mm. Txheej nyias dhau tsis muaj kev tiv thaiv, thiab txheej tuab dhau yuav txo qhov zog ntawm qhov sib koom ua ke. Cov khoom yuav tsum tau welded kuj tuaj yeem muab tso rau hauv lub thawv rau lub tshuab nqus tsev brazing. Lub thawv yuav tsum tau sau nrog getter. Piv txwv li, Zr nqus cov roj ntawm qhov kub siab, uas tuaj yeem tsim lub tshuab nqus tsev hauv zos, yog li tiv thaiv kev oxidation ntawm qhov chaw alloy.

Rooj 15 cov khoom siv kho tshuab ntawm Lub Tshuab Nqus Tsev Brazed Joints ntawm cov khoom siv nickel base superalloys

Lub microstructure thiab lub zog ntawm qhov sib koom ua ke ntawm Superalloy hloov pauv nrog qhov sib txawv ntawm brazing, thiab kev kho mob diffusion tom qab brazing yuav ua rau kom muaj qhov siab tshaj plaws ntawm qhov sib koom ua ke. Piv txwv li, Inconel alloy, qhov sib txawv siab tshaj plaws ntawm Inconel sib koom ua ke nrog b-ni82crsib tuaj yeem ncav cuag 90um tom qab kev kho mob diffusion ntawm 1000 ℃ rau 1H; Txawm li cas los xij, rau cov pob qij txha brazed nrog b-ni71crsib, qhov sib txawv siab tshaj plaws yog li 50um tom qab kev kho mob diffusion ntawm 1000 ℃ rau 1H.

3) Kev sib txuas ntawm cov kua theem ib ntus Kev sib txuas ntawm cov kua theem ib ntus siv cov hlau sib xyaw (kwv yees li 2.5 ~ 100um tuab) uas nws qhov chaw yaj qis dua cov hlau hauv paus ua cov hlau ntim. Hauv qab qhov siab me me (0 ~ 0.007mpa) thiab qhov kub thiab txias tsim nyog (1100 ~ 1250 ℃), cov khoom siv interlayer ua ntej yaj thiab ua rau cov hlau hauv paus ntub. Vim yog qhov sib kis sai ntawm cov ntsiab lus, isothermal solidification tshwm sim ntawm qhov sib koom ua ke los tsim qhov sib koom ua ke. Txoj kev no txo ​​qhov xav tau sib phim ntawm qhov chaw hlau hauv paus thiab txo qhov siab vuam. Cov yam ntxwv tseem ceeb ntawm kev sib txuas ntawm cov kua theem ib ntus yog qhov siab, qhov kub thiab txias, lub sijhawm tuav thiab cov khoom sib xyaw ntawm cov txheej. Siv qhov siab tsawg dua kom khaws qhov chaw sib txuas ntawm qhov vuam kom zoo. Qhov kub thiab sijhawm cua sov muaj feem cuam tshuam loj rau kev ua haujlwm ntawm qhov sib koom ua ke. Yog tias qhov sib koom ua ke yuav tsum muaj zog npaum li cov hlau puag thiab tsis cuam tshuam rau kev ua haujlwm ntawm cov hlau puag, cov txheej txheem txuas ntawm qhov kub siab (xws li ≥ 1150 ℃) thiab lub sijhawm ntev (xws li 8 ~ 24 teev) yuav tsum tau txais; Yog tias qhov zoo ntawm qhov sib koom ua ke raug txo qis lossis cov hlau puag tsis tuaj yeem tiv taus qhov kub siab, yuav tsum siv qhov kub qis dua (1100 ~ 1150 ℃) thiab lub sijhawm luv dua (1 ~ 8 teev). Cov txheej nruab nrab yuav tsum siv cov hlau puag sib txuas ua cov khoom xyaw yooj yim, thiab ntxiv cov khoom txias sib txawv, xws li B, Si, Mn, Nb, thiab lwm yam. Piv txwv li, cov khoom xyaw ntawm Udimet alloy yog ni-15cr-18.5co-4.3al-3.3ti-5mo, thiab cov khoom xyaw ntawm cov txheej nruab nrab rau kev sib txuas kua dej ib ntus yog b-ni62.5cr15co15mo5b2.5. Tag nrho cov ntsiab lus no tuaj yeem txo qhov kub yaj ntawm Ni Cr lossis Ni Cr Co alloys mus rau qhov qis tshaj plaws, tab sis qhov cuam tshuam ntawm B yog qhov pom tseeb tshaj plaws. Tsis tas li ntawd, qhov nrawm diffusion siab ntawm B tuaj yeem ua kom cov hlau sib xyaw thiab cov hlau puag sib xyaw sai sai.