Aluminium thiab aluminium alloy raj yog dav siv nyob rau hauv roj av thiab tshuaj, tub yees thiab HVAC, aerospace, hluav taws xob xa mus thiab kev thauj mus los ntawm cov dej nyob rau hauv kev lag luam scenarios vim lawv tsis tshua muaj ceev, zoo heev corrosion kuj, thiab zoo heev thermal thiab hluav taws xob conductivity. Thaum lub sijhawm ua haujlwm ntev thiab kev ua haujlwm, cov raj txhuas txhuas ua rau ntau hom kev puas tsuaj los ntawm kev cuam tshuam rau txhua yam, nruab nrab corrosion, kev nyuaj siab qaug zog thiab lwm yam. Kev siv cov thev naus laus zis kho kom tsim nyog tuaj yeem txo cov nqi hloov pauv thiab txo cov voj voog kaw ntawm qhov chaw ntawm kev ua kom muaj kev nyab xeeb ntawm cov qauv, uas yog qhov tseem ceeb ntawm kev sib txuas hauv kev lag luam hauv cov kav dej thiab kev saib xyuas.
1. Hom kev puas tsuaj thiab ua rau cov hlau tsis huv
Aluminium raj puas tuaj yeem muab faib ua peb pawg los ntawm qib kev puas tsuaj: kev puas tsuaj saum npoo, kev puas tsuaj thiab kev puas tsuaj corrosion. Qhov ua rau thiab theem kev pheej hmoo ntawm kev puas tsuaj sib txawv sib txawv:
Kev puas tsuaj saum npooNws feem ntau suav nrog kev khawb ntawm qhov chaw, qhov chaw ntiav thiab qhov chaw deformation, feem ntau tshwm sim los ntawm kev sib tsoo thaum lub sij hawm thauj mus los thiab kev teeb tsa, kev cuam tshuam ntawm cov khoom txawv teb chaws, thiab khawb thaum lub sijhawm ua haujlwm thiab tu. Qhov kev puas tsuaj tsuas yog cuam tshuam rau cov tsos thiab kev ncaj ncees ntawm cov oxide zaj duab xis nto; dents nrog qhov tob tshaj 10% ntawm phab ntsa thickness yuav ua rau cov kev ntxhov siab hauv zos, thiab muaj kev pheej hmoo ntawm kev tawg nyob rau hauv lub voj voog siab.
Kev puas tsuajNws suav nrog cov kab nrib pleb, perforations thiab pob txha tawg, uas yog cov ntaub ntawv txaus ntshai tshaj plaws ntawm kev puas tsuaj. Cov kab nrib pleb feem ntau tshwm sim los ntawm kev hloov pauv kev ntxhov siab, kev ntxhov siab ntau dhau los lossis kev nthuav tawm ntawm cov vuam tsis xws luag; perforations feem ntau yog tshwm sim los ntawm corrosion nkag los yog cuam tshuam ntawm cov khoom ntse; tawg yog qhov kawg tsis ua hauj lwm ntawm kev puas tsuaj uas tsis kho, uas yuav ncaj qha ua rau nruab nrab to thiab kaw lub kaw lus.
Corrosion puasTxhuas nws tus kheej muaj kev tiv thaiv corrosion nyob rau ntawm qhov ntom ntom oxide zaj duab xis ntawm qhov chaw, tab sis corrosion tsis ua hauj lwm tseem tshwm sim nyob rau hauv tej yam kev mob ua hauj lwm:
Pitting corrosion: Nyob rau hauv marine thiab tshuaj ib puag ncig nrog enriched chloride ions, oxide zaj duab xis yog nyob rau hauv lub zos puas los tsim pitting corrosion pits, uas yooj yim tsim tob rau hauv lub raj phab ntsa.
Crevice corrosion: Nruab nrab tuav nyob rau hauv nqaim qhov khoob ntawm cov yeeb nkab flanges thiab kev txhawb nqa kev sib txuas ua rau thaj chaw tsis muaj oxygen hauv zos thiab ua rau muaj kev xeb.
Galvanic corrosion: Thaum txhuas raj txuas ncaj qha rau cov hlau tsis sib xws xws li tooj liab thiab hlau, electrochemical corrosion tshwm sim vim electrode muaj peev xwm sib txawv, thiab txhuas raws li cov anode accelerates dissolution.
2. Lub hom phiaj kho cov txheej txheem rau kev puas tsuaj sib txawv
Kev kho lub raj aluminium yuav tsum ua raws li cov hauv paus ntsiab lus ntawm "kev ntsuam xyuas ua ntej, kev tsim kho tom qab, tib qib", uas yog, ua ntej kom meej qhov kev puas tsuaj qhov tob thiab qhov ntsuas los ntawm kev kuaj tsis muaj kev puas tsuaj, tom qab ntawd phim cov txheej txheem sib xws raws li qib siab thiab nruab nrab cov yam ntxwv, thiab xyuas kom lub zog thiab corrosion kuj tom qab kho tsis qis dua tus qauv tsim ntawm lub hauv paus hlau.
2.1 Kev kho me ntsis ntawm qhov chaw puas
Muaj feem xyuam rau cov kav dej uas tsis tshua muaj siab thiab tsis muaj teeb meem nruab nrab nrog khawb qhov tob Tsawg dua lossis sib npaug li 0.5 hli, qhov tob tob tsawg dua lossis sib npaug li 10% ntawm phab ntsa tuab thiab tsis muaj kab nrib pleb.
Kev sib tsoo thiab polishing khoUa ntej, zom qhov chaw puas ntsoog raws axial kev taw qhia ntawm lub raj xa dej nrog 800 #-1200 # cov ntawv xuab zeb zoo kom tshem tawm cov burrs thiab xoob oxide txheej, tom qab ntawd ua daim iav polishing nrog lub log wool matched nrog polishing paste, thaum kawg so huv si thiab tshuaj tsuag pob tshab txhuas tiv thaiv tus neeg saib xyuas kom rov qab du nto thiab oxide zaj duab xis txuas ntxiv. Txoj kev no tsuas yog rau cov tsos thiab kho qhov ntiav ntiav, thiab tsis hloov lub zog ntawm cov qauv.
Local anodic oxidation zaj duab xis ntxivRau cov xwm txheej uas yuav tsum tau muaj kev tiv thaiv corrosion nruj, cov txheej txheem anodic oxidation hauv zos tau txais yuav tom qab sib tsoo: insulate thiab tiv thaiv thaj chaw ib puag ncig ntawm qhov puas, npaj dilute sulfuric acid electrolyte, thiab ua anodic oxidation kho rau ntawm qhov chaw kho nrog cov khoom siv oxidation me me los tsim cov oxide txheej nrog tib lub thickness raws li cov thawj zaj duab xis, thiab cov txheej txheem ntawm cov hlau tuaj yeem ncav cuag qhov kev ua tau zoo.
2.2 Kev Kho Hniav Deformation
Rau cov neeg kho tshuab deformation puas tsuaj qhov twg lub raj phab ntsa yog dented tab sis tsis muaj cov kab nrib pleb tshwm sim thiab cov phab ntsa thickness tsis pom tseeb thinning, cov txheej txheem coj los xaiv raws li txoj kab uas hla thiab phab ntsa thickness:
Cov raj me me (DN Tsawg dua lossis sib npaug rau 50): Txais cov txheej txheem jacking tshuab. Ntxig lub taub hau jacking adjustable los ntawm sab hauv ntawm lub raj xa dej, ua raws li qhov nruab nrab ntawm cov hniav thiab siv lub siab maj mam thawb cov hniav tawm kom zoo ib yam li cov tube phab ntsa radian qub. Saib xyuas qhov deformation nrog lub dial taw qhia thaum lub sij hawm tus txheej txheem kom tsis txhob dhau jacking ua rau lub raj phab ntsa tawg.
Loj-diameter raj (DN ＞ 100): Txais hydraulic tube expanding txoj kev. Muab lub taub hau tshwj xeeb roj hmab tso rau hauv txoj hauj lwm dents, txhaj cov dej siab kom nthuav dav lub taub hau, thiab sib npaug ntawm lub raj phab ntsa kom ua tiav rov qab. Nws yog tsim rau industrial txhuas raj nrog tuab phab ntsa thiab muaj zog rigidity.
Kev ntsuam xyuas kev nkag mus yuav tsum tau ua tom qab kho deformation kom paub meej tias tsis muaj cov kab nrib pleb zais.
2.3 Kho qhov tawg thiab perforation
Xws li kev puas tsuaj ncaj qha cuam tshuam rau lub siab-kev muaj peev xwm ntawm cov kav dej, thiab kev kho kom ruaj khov lossis kho ib ntus yuav tsum raug xaiv raws li qhov kev puas tsuaj loj thiab kev ua haujlwm siab.
Vuam kho (kev kho tas mus li, nruab nrab thiab siab ua haujlwm siab)Vuam yog cov txheej txheem kho tseem ceeb rau kev puas tsuaj ntawm cov hlab ntsha aluminium. Gas Tungsten Arc Vuam (GTAW/TIG) yog qhov zoo dua, thiab Gas Hlau Arc Vuam (GMAW/MIG) tuaj yeem siv rau cov hlab ntsa tuab tuab. Cov ntsiab lus tseem ceeb ntawm cov txheej txheem yog raws li nram no:
Pre-welding kev kho mob: Ua tib zoo zom thiab tshem tawm cov oxide zaj duab xis nyob rau hauv 20-30mm ntawm ob sab ntawm lub vuam nrog stainless hlau hlau txhuam, ces degrease thiab deoil nrog acetone los yog tus neeg saib xyuas tshwj xeeb. Lub melting point ntawm aluminium oxide zaj duab xis yog siab li 2050 degree, ntau dua li lub hauv paus hlau melting point ntawm 660 degree. Kev ntxuav tsis tiav yuav ua rau tsis tiav fusion defects.
Cov khoom siv thiab cov parameter: AC fais fab mov yuav tsum tau siv rau GTAW, thiab cov nyhuv cathode atomization yog siv los rhuav tshem cov oxide zaj duab xis generated thaum vuam; preheat rau 100-150℃ua ntej welding thaum phab ntsa thickness yog ＞10mm, thiab tswj lub interpass kub nyob rau hauv 150℃kom txo thermal stress thiab overheating embrittlement ntawm lub hauv paus hlau.
Kev ua haujlwm specification: Txais siv high-tam sim no vuam ceev kom txo tau lub sij hawm cua sov ntawm lub hauv paus hlau; lub arc crater yuav tsum tau sau kom tsis txhob arc crater tawg; Cov kav dej loj loj yuav tsum tau txais ob tog synchronous GTAW los ntawm ob lub vuam los txhim kho vuam zoo thiab vuam efficiency.
Kev kho tom qab vuam: Txias ib txwm thiab maj mam, thiab dej txias yog txwv tsis pub kom tawg vim qhov txias txias; Tom qab ntxuav lub weld slag rau ntawm qhov chaw weld, ua dye penetrant kuaj kom paub meej tias tsis muaj qhov tsis xws luag. High-pressure pipelines xav tau kev kuaj ultrasonic ntxiv uas tsis yog kev puas tsuaj.
Kev kho txias (kev kho ib ntus, kev ua haujlwm tsis tshua muaj siab)Rau cov kav dej nrog dej thiab roj nruab nrab nrog lub siab tsawg dua lossis sib npaug ntawm 1.6MPa, lossis cov xwm txheej ua haujlwm uas tsis tso cai ua haujlwm kub, aluminium-based epoxy kho compound lossis tshwj xeeb yeeb nkab kho thaj tuaj yeem siv tau:
Aluminium-raws li epoxy kho compound: Nws yog tsim los ntawm ob lub ntsiab lus epoxy resin ntim nrog txhuas hmoov. Tom qab sib tsoo lub periphery ntawm lub perforation kom ntxhib, huv si thiab qhuav, nias lub npaj kho compound rau hauv lub qhov, du nto, thiab nws muaj peev xwm ua hauj lwm nyob rau hauv siab tom qab kho ntawm chav tsev kub rau 24 teev. Nws yog tsim rau me me qhov to nrog txoj kab uas hla Tsawg dua los yog sib npaug li 5 hli.
Tshwj xeeb aluminium tube kho thaj ua rau thaj: Sib txuam nrog cov nplaum tshwj xeeb, txiav lub thaj kom dhau qhov kev puas tsuaj ntawm ntau tshaj 20 hli, muab tshuaj txhuam thiab cog nws tom qab siv clamping quab yuam los pab kho. Nws muaj kev ruaj ntseg sealing kev ua tau zoo thiab tuaj yeem siv los ua kev kho mob xwm txheej ceev.
Txoj kev hloov yeeb nkab seemThaum qhov tawg ntev tshaj 1/3 ntawm cov yeeb nkab txoj kab uas hla, qhov perforation txoj kab uas hla yog ＞ 20mm, los yog qhov kev puas tsuaj ntau tshaj 1/2 ntawm tag nrho cov ncig, tsis pom zoo kho hauv zos. Cov yeeb nkab puas yuav tsum raug txiav tawm thiab hloov nrog cov yeeb nkab tshiab ntawm cov khoom qub thiab cov lus qhia tshwj xeeb, txuas nrog lub taub qab vuam, thiab cov vuam yuav tsum tau ua raws li cov yeeb nkab tshiab.
2.4 Corrosion Damage Kho
Me me nto corrosionTom qab sib tsoo kom tshem tawm cov khoom siv corrosion thiab xoob oxide txheej thiab nthuav tawm cov xim hlau, koj tuaj yeem xaiv cov tshuaj pleev xim tshwj xeeb los tiv thaiv corrosion rau txhuas, qhwv aluminium ntawv ci viscoelastic daim kab xev thiab lwm txoj hauv kev los tsim kho cov txheej txheem tiv thaiv corrosion. Thaum siv viscoelastic daim kab xev, ua ntej sau cov pits corrosion nrog txuam muab tshuaj txhuam, thiab daim kab xev txheej dav yuav tsum tsis pub tsawg tshaj 50 hli dhau ntawm ntug kev puas tsuaj los xyuas kom meej sealing tiav.
Local corrosion thinningThaum cov yeeb nkab phab ntsa yog uniformly thinned vim corrosion tab sis tsis perforated, cov txheej txheem txheej txheej txheej txheem tuaj yeem siv tau: cua carbon fiber ntau cov khoom siv los yog iav fiber ntau cov khoom siv rau ntawm phab ntsa polished thiab ntxuav cov yeeb nkab, thiab tsim cov txheej txheem los ntawm resin curing los ua rau phab ntsa thickness poob thiab rov qab muaj peev xwm-cov kabmob. Nws yog qhov tsim nyog rau cov kav dej hauv kev pabcuam uas tsis yooj yim rau kev kaw rau kev hloov pauv.
Loj-qhov chaw corrosionThaum lub cheeb tsam corrosion ntau tshaj 30% ntawm cov kav xa dej, los yog cov phab ntsa seem yog tsawg dua 70% ntawm cov phab ntsa tsim, kev kho cov nqi qis dua, thiab tag nrho cov seem ntawm cov kav dej yuav tsum tau hloov.
3. Kev soj ntsuam zoo thiab cov qauv kev lag luam rau kev kho Aluminium Tube
Kev kho kom zoo ntawm txhuas raj yog ncaj qha ntsig txog kev ua haujlwm kev nyab xeeb, thiab kev tshuaj xyuas ntau qhov yuav tsum tau ua raws li nruj raws li cov qauv kev lag luam:
Kev tshuaj xyuas qhov tshwm sim: Qhov chaw vuam yuav tsum tau ua tib zoo tsim yam tsis muaj qhov tsis xws luag xws li tawg, qhov pores, slag inclusions thiab hlawv-los ntawm; Txoj kev hloov ntawm cov yeeb nkab phab ntsa hauv qhov chaw kho yuav tsum du yam tsis muaj qhov pom tseeb protrusions thiab dents.
Kev tshuaj xyuas nruj: Cov raj xa dej siab yuav tsum tau kuaj xyuas hydrostatic tom qab kho, nrog rau qhov kev sim siab yog 1.5 npaug ntawm qhov tsim siab, thiab tsis muaj qhov xau lossis pom tseeb siab poob tom qab tuav lub siab rau 30 feeb yog tsim nyog; pneumatic xeem tuaj yeem raug coj los siv rau cov xwm txheej uas qhov kev ntsuas hydrostatic tsis haum, nrog rau qhov kev ntsuas siab yog 1.15 npaug ntawm qhov tsim siab.
Kev kuaj tsis muaj kev puas tsuaj: Kev kho cov kav dej nruab nrab thiab siab siab yuav tsum tau ua 100% kev ntsuam xyuas kev nkag siab (PT) txhawm rau txheeb xyuas cov kab nrib pleb, thiab cov kav dej tseem ceeb yuav tsum raug kuaj xyuas hluav taws xob ntxiv (RT) lossis kuaj ultrasonic (UT) txhawm rau txheeb xyuas qhov zoo hauv fusion.
Kev lag luam tus qauv hauv paus: Vuam kev tsim kho yuav tsum sivTxoj Cai rau Kev Tsim Kho thiab Kev Txais Kev Vuam Engineering ntawm Cov Khoom Siv Hauv Tebchaws thiab Kev Siv Hluav Taws XobGB 50236-2011; corrosion kho thiab kev tiv thaiv yuav tsum ua raws li cov kev cai ntawmTag Nrho Lub neej voj voog ntawm Pipeline Corrosion Control Engineering-Cov Lus QhiaGB/T 37190.
4. Kev tiv thaiv thiab lub neej txuas ntxiv ntsuas tom qab kho
Qhov chaw kho feem ntau yog qhov tsis muaj zog txuas ntawm cov kav dej. Kev tiv thaiv kev rov qab zoo tuaj yeem txuas ntxiv lub neej kev pabcuam tag nrho:
Ua kom tiav cov txheej txheem tiv thaiv corrosion: Tom qab kev kho vuam, kev kho kev tiv thaiv corrosion yuav tsum tau ua nyob rau hauv qhov chaw vuam thiab tshav kub, thiab cov txheej txheem tiv thaiv corrosion zoo ib yam nrog cov kav dej qub yuav tsum nyiam kom tsis txhob tsim cov ntsiab lus tshiab corrosion tsis muaj zog.
Tsis txhob galvanic corrosion: Sim siv cov ntaub ntawv txhuas ntawm qib tib yam li cov hlau puag thaum kho; Yog tias cov hlau tsis sib xws yuav tsum tau txuas nrog, txhim kho cov khoom siv hluav taws xob los yog siv cov pob qij txha dielectric kom cais tawm thiab txiav tawm ntawm electrochemical corrosion circuit.
Optimize kev khiav hauj lwm thiab kev tswj xyuas: Tsim kom muaj kev tshuaj xyuas cov kav dej tsis tu ncua, thiab ua cov kev ntsuam xyuas phab ntsa tuab thiab kev ntsuam xyuas corrosion ib xyoos ib zaug rau cov kav dej hauv qhov chaw corrosive; tswj cov tshuaj chloride ion cov ntsiab lus thiab pH tus nqi ntawm cov khoom nruab nrab kom txo qis hauv corrosion ua rau.
5. Kev txiav txim siab nyiaj txiag ntawm kev kho thiab hloov pauv
Aluminium tube puas tsuaj pov tseg yuav tsum txiav txim siab raws li kev ua tau zoo thiab kev them nqi:
Cov xwm txheej uas xav tau kho: Qhov kev puas tsuaj ntau me me thiab cov qauv kev ntseeg tau zoo; lub raj xa dej yog cov tshwj xeeb tshwj xeeb lossis cov khoom tuaj txawv teb chaws, nrog rau kev yuav khoom ntev thiab tus nqi siab; cov txheej txheem tsim khoom tsis tuaj yeem raug kaw rau lub sijhawm ntev, thiab kev kaw qhov poob yog ntau dua li cov nqi kho.
Cov xwm txheej uas xav tau kev hloov pauv: Kev puas tsuaj loj, thaj tsam loj corrosion lossis qaug zog tawg; tus nqi kho dua 60% ntawm tus nqi ntawm cov kav dej tshiab; lub raj xa dej tau mus txog qhov tsim kev pabcuam lub neej thiab kev ua haujlwm tag nrho yog degraded.
Kev kho aluminium raj raj yog ib qho kev ua haujlwm zoo, lub hauv paus tseem ceeb ntawm kev soj ntsuam xyuas lub xeev kev puas tsuaj, sib piv cov txheej txheem kho kom tsim nyog, thiab nruj me ntsis tswj kev tsim kho kom zoo. Rau kev kho aluminium raj hauv cov xwm txheej uas muaj kev pheej hmoo siab xws li kev kub siab thiab hluav taws xob / hluav taws xob tawm xov xwm, nws yuav tsum tau ua los ntawm cov kws tshaj lij nrog cov kev tsim nyog los xyuas kom muaj kev nyab xeeb thiab ruaj khov ntawm kev kho cov kav dej.
