1. Lub ATTM A638 Cov Ntawv Qhia Tshwj Xeeb npog cov dej nag - haib - bined alloy tuav. Dab tsi yog qhov tseem ceeb ntawm cov yam ntxwv uas tsis sib xws li alloys zoo li A-286, 800, 825, thiab 925 hauv qab no nws ua rau lawv daim ntawv thov?
Tus yam ntxwv uas tsis pub tus cwj pwm rau cov nickel no - Cov toys} Lawv lub peev xwm ua kom muaj zog ntawm nag lossis daus ua kom tawv). Thaum Astm A638 nws tus kheej yog cov qauv dav dav uas tuaj yeem muab cov khoom siv tseem ceeb tshaj plaws uas yuav ua haujlwm kom sov ua ke uas tsis muaj zog nrog cov hlau tsis muaj zog.
Cov nag los nag lossis tawv tawv cuam tshuam nrog ob {- theem thermal txheej txheem:
Kev kho cov tshuaj: Lub alloy yog rhuab rau qhov kub siab uas txhua qhov kev daws teeb meem txhua lub sijhawm (zoo li Nickel {} Chromium Matrix, ces nrawm nrawm. Qhov no ua rau lub ntsej muag muag, ducab, thiab homogeneous xeev, zoo tagnrho rau kev machining thiab kev siv hluav taws xob.
Kev laus kev kho mob: ib feem yog rhuab rau ib qho nruab nrab kub thiab tuav rau lub sijhawm tshwj xeeb. Qhov no tso cai rau zoo, uniformly faib intermetallic hais (xws li theem gamma ['] ntu 12 thiab 925) los nag tawm ntawm cov kev daws teeb meem supersaturated. Cov lus no ua rau muaj kev tshem tawm nyob rau hauv cov qauv siv lead ua cov qauv siv lead ua kom muaj zog, ua rau muaj zog ntau ntxiv thiab lub zog tensile.
Cawv ntawm daim ntawv thov: Lub peev xwm no dictates lawv siv nyob rau hauv high {{} kev ntxhov siab, high-}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}} pa taws ib puag ncig. Tsis zoo li alloys uas cia siab rau cov khoom {} Kev daws teeb meem ntxiv (zoo li alloy 600), cov nag ntoos- Cov qib tsis tuaj yeem siv rau:
Fasteners: high {{{{{}} Lub zog lub zog, thiab txiv hmab txiv ntoo, thiab txiv ntoo rau kev sib txuas hauv siab rau hauv cov hlab siab thiab cov turbines.
Cov Cheebtsam: cov qauv, Shafts, thiab txiav uas yuav tsum tawm ntawm kev hnav, galling, thiab kev ntxhov siab ntau.
TWJ ShaFTS: Tshwj xeeb hauv kev tawm tsam thiab cov ntawv thov tom qab kev ua haujlwm uas yog qhov yuav tsum tau muaj zog.
Aerospace Cheebtsam: cov qauv hauv cov roj turbine cav.
Qhov kev suav nrog ntawm alloy 800 thiab 825 hauv cov npe no yog nuanced. Txheem alloy 800 (tsis yog N08800) feem ntau yog cov khoom -} tshuaj tov zog txuag alloy. Txawm li cas los xij, ib qeb tshwj xeeb, suav tias yog 88810), yog tswj hwm rau cov xim loj thiab cov ntsiab lus carbon} Ib yam li ntawd, tus qauv alloy 825 tsis yog nagitation-} tawv; Nws suav cuam tshuam ib qho yuav tsum tau rau ib qho siab- Lub zog bar daim ntawv, txawm tias nws muaj peev xwm ua lub zog ntawm lub zog {}}} kev daws.
2. Ntawm incoloy a-286, 825, thiab 925, uas muaj lub zog siab tshaj plaws ntawm kev nce siab kub, thiab yog li cas metallurgical qab no?
Incoloy A-286 (tsis yog S66286) Muaj lub zog tshaj plaws ntawm kev nce siab kub (feem ntau txog li 1300℃F / 700 degree) ntawm peb alloys.
Lub ntsiab lus metallurgical nyob hauv nws cov nag lossis daus tshwj xeeb - qhov tawv thiab tawv tawv. - 286 yog ib tug hlau {{}}} Chromium Supereraloy ntxiv dag zog rau los ntawm Coherent, xaj Gamma Prime (') theem, NI3 (TI, AL). Tus yuam sij rau nws kev ua tau zoo tshaj yog qhov ruaj khov thiab tiv taus kom coarsening (ostwald ripening) ntawm cov 'precipitates.
Kev sib xyaw: A-286 muaj cov txiaj ntsig zoo ntawm titanium (~ 2.0%) thiab txhuas (~ 0.2%). Thaum lub sijhawm kev tu cua sov (feem ntau ib puag ncig 1325 Qib F / 718 Qib rau 16 teev), cov ntsiab lus no ua ib qho zoo heev, ntom, thiab kev sib cais ntawm cov 'hais. Cov lus no tau ua tau zoo heev ntawm kev thaiv kev tshem tawm cov lus qhia, txawm tias lub zog cua sov uas thermal lub zog feem ntau cia cov kev tsis txaus siab mus rau kev cuam tshuam los ntawm kev cuam tshuam tsis muaj zog.
Piv:
Alloy 925 kuj nyuaj los ntawm '(NI3 (Ti, al)), tab sis nws muaj nyob rau kev sib xyaw ntawm cov kev ua kom muaj zog thiab kev pabcuam corrosion tsis kam nyob rau hauv cov chaw muab kev pab. Nws qhov siab - sov zog ruaj khov feem ntau qis dua li ntawm A-286.
Alloy 825 yog cov khoom -}} daws cov tshuaj tiv thaiv ntxiv. Nws lub zog ntawm chav tsev kub yog qhov zoo, tab sis nws "softens" nrawm nrawm dua vim tias nws tsis muaj peev xwm ntxiv dag. Nws lub zog yog muab tau los ntawm cov atomic - theem ua ke thiab chromenum thiab chromenum nyob rau hauv lub npib tsib xee, muaj txiaj ntsig uas ploj zuj zus nrog kev nce thermal zog.
Yog li ntawd, rau cov ntawv thov nyiam roj turbine cav, siab}}}} kub fasteners,} qhov kev xaiv qhov kub thiab txias rau qhov chaw tsav tsheb. Alloys 925 thiab 825 yog xaiv thaum corrosion tsis kam yog qhov tseem ceeb dua tshaj qhov kawg kub lub zog.
3. Rau cov ntawv thov Sour (muaj cov h₂s) xav tau high {1} Txoj kev xaiv muaj zog tshaj plaws dua li kev xaiv ib-286 bar?
Kev xaiv ntawm Incoloy 925 (Tsis yog N09925) dhau incoloy rau incoloy ntawm incoloy rau ntawm cov kev pabcuam ntawm yav dhau los yog sulfide kev ntxhov siab tawg (SSC).
SSC yog ib hom tshuaj ntawm hydrogen embrittlement uas tshwm sim hauv hypogion hydrogen (H⁺)
Qhov teeb meem nrog - 286: Thaum {{} {{} {{5} {{5} {{5} {{5} Tsis tas li ntawd, kev laus kev kho mob txo nws lub zog uas yog inherently ntau dua li nor0 raws li txoj kev ua lag luam tau yooj yim (feem ntau HRC 34-36) teev rau cov kev pab cuam.
Qhov zoo ntawm Alloy 925: Alloy 925 yog tsim tshwj xeeb thiab tsim nyog rau kev pabcuam siur. Nws muaj pes tsawg leeg thiab kev kho cua sov tuaj yeem ua tiav cov kev ua kom zoo tshaj plaws:
Lub zog siab: nws tuaj yeem yog nag teeb meem nyuaj rau cov txiaj ntsig zoo tshaj 110 ksi, ua nws haum rau high {1} ntxhov siab cov khaub ncaws siab.
Kev tswj hwm lub hardness: nws kev kho mob laus tuaj yeem ua kom paub meej tias qhov kawg ntawm MR0175 / ISO 1515) tsawg dua lossis sib npaug ntawm HRC 35 rau qhov no alloy).
Kev Intrentent Corrosion Kuj: Cov ntsiab lus Nickel muaj kev tiv thaiv kab mob chloride kev tawg, thaum lub molybdenum kev ntxhov siab rau pitting thiab txo cov kua qaub ntau nyob hauv cov chaw ib puag ncig.
Hauv cov ntsiab lus, rau lub qaub Sour kev tso pa ncej, ib qho AVTM A638 Incoloy 925 bar nyob rau hauv cov kev daws {}}}} Mob muaj lub zog tsim nyogNrog lav SSC KujCov. Ib-286 bar, txawm hais tias nws lub zog siab, yuav ua rau ib qho tsis txaus ntshai ntawm tam sim ntawd, brittle tsis muaj nyob rau hauv tib qho chaw.
4. Thaum paub tseeb tias ASTM A638 puag ncig bar rau ib qho tseem ceeb (cov khoom tseem ceeb thiab tshuaj siv tshuaj uas yuav tsum tau txheeb xyuas, thiab lawv qhia li cas?
Kev qhia txog AVTM A638 puag ncig cov ntawv thov yuav tsum tau saib xyuas cov tshuaj lom neeg thiab cov khoom siv kho kom zoo nkauj {{1}- kev pab.
Tus yuam sij tshuaj (Kev Ntsuam Xyuas Kev Ntsuas Cua Sov):
Nickel (NI), chromium (CR), hlau (FE): Cov kab hauv paus: Cov NI, siab, siab kawg rau oxidation tsis kam).
Molybdenum (mo): Tseem Ceeb rau Pitting thiab Crevice Corrosion Resistance. Ib tug tseem ceeb sib txawv rau Alloy 825 thiab 925.
Titanium (ti) thiab txhuas (al): Lub hnub nyoog tseem ceeb {{
Cov pa roj carbon (c): yuav tsum tau tswj hwm. Cov pa roj carbon ntau tuaj yeem ua rau tsim cov chromium carbides ntawm cov ciaj ciam av, txo corrosion tsis kam. Nyob rau hauv high {-} sov cov qib nyiam 800H, carbon tau tswj hwm rau theem kev ua kom muaj zog.
Sulphurur (s) thiab phosphorus (P): Cov cuab yeej pab pawg khaws cia kom muaj kev ua haujlwm tau zoo thiab tiv thaiv embittlement.
Cov khoom tseem ceeb (ib daim coupon):
Tensile lub zog & tawm lub zog (0.2% offset): cov thawj qhia ntawm cov khoom siv thauj khoom - nqa muaj peev xwm. Rau ib qho nag ntsis -} Hardened Bar, cov txiaj ntsig lub zog yog feem ntau tsim qauv ntsuas.
Elongation & txo thaj chaw: kev ntsuas ductility. Lawv qhia cov ntaub ntawv muaj peev xwm deform plastically ua ntej pob txha lov, uas yog qhov tseem ceeb rau nqus overloads thiab muab cov tawv.
Hardness (brinell lossis rockwell): kev paub tseeb ceev, tsis ncaj ncees rau lub zog thiab kev kho cua sov. Nws tseem yog kev cuam tshuam ncaj qha mus rau SSC tsis kam hauv cov ntawv thov kev pabcuam ntawm cov ntaub ntawv thov.
Charpy V - next} negch cuam tshuam lub zog: ib qho khoom siv ncaj qha ntawm kev muaj zog, lossis cov khoom siv muaj peev xwm nqus lub zog nyob rau hauv lub xub ntiag ntawm qhov khuam. Qhov no yog qhov yuav tsum tau ua rau cov khoom siv hauv qis- kub kev pab lossis cov kev kawm kom muaj kev thauj khoom zoo.
Rau kev tivthaiv xws li ib tug turbine hniav txhaws los ntawm ib theem zoo ntawm TI + AL thiab lub txiaj ntsig tawm lub zog thiab tej yam hluav taws xob. Rau lub valve qia nyob rau hauv cov tshuaj lom neeg cog ua los ntawm alloy 925, lub lav
5. Nyob rau hauv cov ntsiab lus ntawm cov khoom thiab cov ntaub qhia, yog qhov tseem ceeb {--}} {1} Ib illoloy 925 rau AFOLOY 925 rau A638?
Ua haujlwm nrog siab - lub zog, nag lossis daus
Machining kev txiav txim siab:
Ua haujlwm hardening: Nickel alloys tseem ceeb tshaj plaws rau kev ua haujlwm sai sai. Qhov no xav tau ntse, zoo - rake tej cuab yeej, thiab qeeb qeeb los xyuas cov cuab yeej hauv qab no - Hardened txheej. Kev cuam tshuam txiav yuav tsum muaj tsawg.
Cov Khoom Siv Khoom Siv: Carbide cov cuab yeej yog tus qauv, tab sis cov cuab yeej Cermet tuaj yeem siv rau cov haujlwm tiav. Siab -}} qhov siab txias yog qhov tseem ceeb kom tswj tau cua sov thiab yaug cov chips.
Xeev rau Machining: lub xeev zoo tagnrho rau kev siv tshuab hnyav yog kev daws -}} annerted mob. Hauv lub xeev no, cov alloy yog ntawm nws cov mosest thiab feem ntau ducast thiab feem ntau condile, tso cai rau cov nqi tshem tawm ntau dua thiab cov ntoo txo qis. Tom qab machinet, feem tiv thaiv yuav ces yauv mus rau kev laus kawg.
Kev Saib Xyuas Tshav Kub:
Nruj dua cov lus qhia rau cov ntsiab lus: Kev daws analing thiab kev laus kub thiab lub sijhawm tsis arbiarary. Lawv tau hais meej meej nyob rau hauv Astm A638 thiab Alloy cov ntaub ntawv cov ntaub ntawv. Kev sib txawv tuaj yeem ua rau tsis tiav ntawm theem, precipually thases (zoo li sigma theem), txhua yam uas muaj kev cuam tshuam zoo dua qub thiab corrosion tsis kam.
Kev tswj cov cua: kev kho cua sov yuav tsum tau ua nyob rau hauv kev tswj hwm cov pa roj oxidation thiab cov pa roj hmab, uas tuaj yeem muab cov ntaub ntawv tiv thaiv kab ntsig "alpha me me uas yuav tsum tau muab tshem tawm los ntawm kev xaiv lossis machining.
Tshaj tawm - Weld Kev Kho Mob Kub (PWtht): Ib daim ntawv qhia tag nrho rov-} kev daws thiab re- lub zog yog feem ntau tsim nyog los kho lub zog ntawm vuam thiab corrosion tsis kam hla tag nrho cov khoom sib tivthaiv. Qhov no ntxiv tus nqi tseem ceeb thiab kev nyuaj siab.
Therefore, a successful fabrication process involves a carefully planned sequence: Procure bar in Solution-Annealed condition -> Machine to near-final dimensions -> Perform final Aging Heat Treatment ->Tiav lub tshuab (yog tias yuav tsum tau ua, sau cia ua kom muaj zog ntxiv). Qhov no ua kom muaj feem ntau ua tau raws li txoj hlua khi nruj thiab corrosion - cov khoom tiv thaiv} Cov khoom siv A638 tau xaiv cov lus qhia.
