Q1: Dab tsi yog qhov sib txawv hauv kev tsim khoom ntawm Hastelloy C seamless yeeb nkab thiab welded yeeb nkab, thiab cov no cuam tshuam li cas?
A:Kev tsim kev sib txawv ntawm seamless thiab welded Hastelloy C yeeb nkab yog lub hauv paus rau lawv cov kev siv. Seamless yeeb nkab yog tsim los ntawm tho ib qho khoom, rhuab billet ntawm Hastelloy alloy (feem ntau C-276, C-22, los yog C-4) thiab ces rotary dov los yog extruding nws mus rau hauv lub hollow raj yam tsis muaj longitudinal sib koom. Cov txheej txheem no, feem ntau ua raws li kev kos duab txias thiab kev daws teeb meem annealing, tsim kom muaj ib qho zoo sib xws, nplej-nruam qauv. Nyob rau hauv sib piv, welded yeeb nkab pib raws li ib tug ca daim ntawv los yog coil, uas yog dov-tsim mus rau hauv ib tug cylindrical zoo thiab ces fusion-welded raws seam.
Qhov tseem ceeb ntawm kev ua tau zoo sib txawv yog nyob rau hauv qhov tsis muaj weld seam. Thaum cov yeeb nkab welded niaj hnub tuaj yeem ua tau zoo heev tiv thaiv corrosion, tshav kub- cuam tshuam cheeb tsam (HAZ) nyob ib sab ntawm lub vuam tseem tuaj yeem ua rau muaj kev sib cais me me lossis cov kev ntxhov siab, txawm tias tom qab tom qab -weld kho cua sov. Cov yeeb nkab tsis muaj seamless, tsis muaj qhov sib koom ua ke, muaj qhov sib txawv ntawm kev tiv thaiv corrosion, txhua yam muaj zog, thiab ductility thoob plaws nws tus ntoo khaub lig- ntu thiab ntev. Qhov no dhau los ua qhov tseem ceeb hauv ib puag ncig uas muaj qhov siab - nrawm, abrasive, lossis cov xov xwm pitting hnyav (xws li, cov tshuaj chlorine ntub dej lossis cov kua qaub sulfuric acid nyob rau hauv qhov kub siab), qhov twg txawm tias qhov kev tawm tsam microscopic nyiam nrog lub vuam seam tuaj yeem pib ua tsis tiav. Tsis tas li ntawd, cov yeeb nkab seamless tuav lub siab zoo tshaj plaws nyob rau hauv kev thauj khoom los yog thermal shock, vim tias tsis muaj lub dav hlau tsis muaj zog. Yog li ntawd, rau cov kev pabcuam tseem ceeb hauv cov tshuab hluav taws xob nuclear, siab - cov tshuaj lom neeg lub zog siab, thiab cov roj av hauv dej thiab cov roj av, cov kav dej Hastelloy C seamless tseem yog tus qauv kub txawm tias nws cov nqi tsim khoom ntau dua.
Q2: Vim li cas Hastelloy C-276 seamless yeeb nkab yog tshwj xeeb tshaj yog muaj nuj nqis nyob rau hauv offshore thiab subsea daim ntawv thov roj thiab roj?
A:Hastelloy C-276 seamless yeeb nkab tau dhau los ua qhov tseem ceeb hauv thaj chaw sab nrauv thiab hauv qab dej hiav txwv vim nws qhov tshwj xeeb tsis kam tiv thaiv kev sib xyaw ntawm cov neeg ua phem: seawater chlorides, hydrogen sulfide (H₂S), carbon dioxide (CO₂), thiab organic acids - feem ntau ntawm kev kub ntxhov thiab nruab nrab mus rau qhov kub thiab txias. Hauv kev tsim cov dej tob, cov khoom xws li hydraulic tswj kab, tshuaj txhaj tshuaj tubing, thiab downhole tubulars yuav tsum tiv thaiv ob hom kev ua tsis tiav: pitting corrosion thiab sulfide stress cracking (SSC).
Seamless kev tsim kho yog ib qho tseem ceeb ntawm no vim hais tias subsea systems koom nrog cov neeg kho tshuab kev nyuaj siab (xws li, khoov thaum lub sij hawm installation, vibration thaum lub sij hawm ntau lawm) thiab thermal cycling. Lub vuam seam, txawm tias corrosion- tiv taus, tuaj yeem ua raws li kev ntxhov siab los yog qhov chaw rau hydrogen-induced cracking nyob rau hauv qaub kev pab cuam (ib NACE MR0175/ISO 15156). Hastelloy C-276's siab molybdenum (15–17%) thiab chromium (14–16%) cov ntsiab lus muab cov yeeb yaj kiab ruaj khov nyob rau hauv muaj cov chlorides, tiv thaiv pitting. Nws cov npib tsib xee- nplua nuj matrix (balance Ni) muaj kev tiv thaiv zoo rau cov tshuaj chloride-induced stress corrosion cracking (SCC) - hom tsis ua hauj lwm uas nkag tau rau austenitic stainless hlau. Ntxiv mus, C-276 yog inherently resistant rau hydrogen embrittlement, ua rau nws muaj kev ruaj ntseg rau H₂S-muaj reservoirs. Daim ntawv seamless kom ntseeg tau tias tsis muaj qhov tshwj xeeb vuam hlau lossis HAZ corrosion tshwm sim, uas tuaj yeem ua rau muaj kev puas tsuaj loj hauv kev tswj hwm lossis cov tubing ntau lawm. Raws li cov chaw sab nrauv txav mus rau hauv qhov siab dua, qhov kub thiab txias ntau dua, kev ntseeg siab ntawm seamless C-276 yeeb nkab txhais ncaj qha rau hauv cov nqi cuam tshuam, txuas ntxiv kev pab cuam lub neej (20+ xyoo), thiab txhim kho kev nyab xeeb.
Q3: Yuav ua li cas cov tshuaj annealing cuam tshuam rau microstructure thiab corrosion kuj ntawm Hastelloy C seamless yeeb nkab?
A:Kev daws annealing yog arguably qhov tseem ceeb tshaj plaws kev kho cua sov kauj ruam hauv kev tsim Hastelloy C seamless yeeb nkab. Tom qab kos duab txias (uas ua haujlwm- ua kom cov hlau tsis muaj zog thiab tuaj yeem ua rau muaj kev ntxhov siab thiab me me nag los nag), cov yeeb nkab tau rhaub rau qhov kub thiab txias - feem ntau yog 1120℃txog 1180℃(2050℃F txog 2150℃F) - ua raws li sai quenching, feem ntau hauv dej. Cov txheej txheem no ua tiav peb lub hom phiaj tseem ceeb:
Ua ntej, nws dissolves tej theem ob precipitated, xws li carbides (xws li, M₆C, M₂₃C₆) thiab intermetallic theem (piv txwv li, mu los yog chi theem), uas tej zaum yuav tau tsim thaum lub sij hawm qeeb txias los yog kub ua hauj lwm. Cov precipitates no, yog tias sab laug nyob rau hauv cov qauv, deplete cov nyob ib sab matrix ntawm chromium thiab molybdenum - lub ntsiab tseem ceeb rau passivation - yog li tsim galvanic hlwb uas pib pitting los yog intergranular nres.
Qhov thib ob, tshuaj annealing homogenizes tshuaj muaj pes tsawg leeg. Hastelloy C alloys yog cov khoom muaj zog- cov kev daws teeb meem, lub ntsiab lus tias Mo, Cr, thiab W (tungsten) yog sib npaug ntawm cov nickel matrix. Annealing ua kom lub cev tsis sib xws, uas txhais tau tias muaj peev xwm tiv thaiv corrosion thoob plaws tag nrho cov yeeb nkab phab ntsa.
Thib peb, nws tshem tawm cov kev ntxhov siab seem ntawm kev tsim khoom, txo qhov kev pheej hmoo ntawm kev ntxhov siab -corrosion tawg hauv kev pabcuam. Txoj kev daws teeb meem zoo-annealed thiab quenched seamless yeeb nkab nthuav tawm tag nrho austenitic, ib zaug -theem microstructure uas tsis muaj cov nplej tas mus li- ciam teb carbides. Lub xeev metallurgical no muab cov alloy qhov siab tshaj plaws paub tiv thaiv rau pitting, crevice corrosion, thiab oxidizing / txo cov kua qaub sib tov. Yog hais tias cov yeeb nkab seamless tsis raug kev daws teeb meem -annealed los yog qeeb - txias, nws cov corrosion kuj tuaj yeem degrade los ntawm 50-80% hauv cov qauv xeem (xws li ASTM G28 Txoj Kev A). Yog li ntawd, cov tuam txhab muaj npe nrov ib txwm muab Hastelloy C seamless yeeb nkab rau hauv cov kev daws teeb meem -annealed mob, nrog cov ntawv pov thawj zeb sau cov kev kho cua sov.
Q4: Cov kev txwv tseem ceeb lossis cov teeb meem yog dab tsi thaum qhia txog Hastelloy C seamless yeeb nkab rau loj - txoj kab uas hla lossis ntev - daim ntawv thov ntev?
A:Thaum Hastelloy C seamless yeeb nkab muaj qhov tsis sib haum xeeb, nws txoj kev siv tsis yog yam tsis muaj kev cuam tshuam thiab kev lag luam, tshwj xeeb tshaj yog thaum cov diameters loj lossis ntev ntev yuav tsum tau ua. Thawj qhov kev txwv yog manufacturability. Kev tsim cov yeeb nkab seamless yuav tsum tho thiab kos cov pob zeb; Qhov siab tshaj plaws sab nraud txoj kab uas hla (OD) kev lag luam muaj rau Hastelloy C seamless yog feem ntau txwv rau ib ncig ntawm 8-10 ntiv tes (DN 200-250), thiab phab ntsa thicknesses saum 1 nti ua nyuaj zuj zus kom ua tiav uniformly. Rau txoj kab uas hla loj, welded yeeb nkab (xws li, ASTM B619) yog tib txoj kev xaiv, raws li seamless mandrel los yog extrusion txheej txheem ua technically nyuaj thiab txwv tsis pub kim.
Qhov thib ob, qhov ntev yog qhov txwv. Seamless kav feem ntau yog muab nyob rau hauv random ntev txog li 6-7 meters (20-23 ko taw) rau nruab nrab diameters, whereas welded yeeb nkab yuav ua tau nyob rau hauv tas li ntawd lengths thiab txiav raws li. Rau cov kav dej ntev ntev (piv txwv li, cov nroj tsuag tshuaj hloov kab ntau tshaj 100 meters), vuam ntau yam seamless spools qhia ntau lub voj voog welds - uas ib nrab negates qhov zoo ntawm lub cev seamless.
Thib peb, tus nqi nce nrawm nrog txoj kab uas hla thiab phab ntsa thickness. Cov khoom siv raw khoom tawm los rau seamless ntau lawm qis dua (txuas thiab kos cov khib nyiab), thiab kev ua haujlwm muaj zog ntau dua - cov kauj ruam hnyav. A 4-inch teem sij hawm 40 seamless C-276 yeeb nkab yuav raug nqi 30-50% ntau dua li qhov sib npaug welded yeeb nkab ua tau raws li qhov sib txawv corrosion. Thaum kawg, kev tshuaj xyuas cov yeeb nkab seamless kuj tseem nyuaj dua: thaum welded yeeb nkab yuav tsum tau kuaj xyuas cov seam (piv txwv li, 100% radiography), seamless yeeb nkab yuav tsum tau puv -lub cev ultrasonic lossis eddy-tam sim no kev ntsuam xyuas kom pom cov voids, laps, los yog segregations ntawm lub billet. Rau cov phab ntsa tuab heev, nrhiav kom pom cov me me suav nrog ua nyuaj. Yog li ntawd, engineers feem ntau siv ib tug hybrid mus kom ze: qhia seamless rau me me - bore, siab - siab, los yog kev nyab xeeb- cov kab tseem ceeb (xws li, ntsuas impulse kab, reactor dip tubes), thiab welded yeeb nkab rau loj-inch, qis-risk headers los yog atmospheric hloov kab.
Q5: Cov qauv kev lag luam dab tsi thiab tsis yog -kev kuaj kev puas tsuaj (NDT) tshwj xeeb siv rau Hastelloy C seamless yeeb nkab rau kev pabcuam tseem ceeb?
A:Hastelloy C seamless yeeb nkab yog tswj hwm los ntawm ntau yam ASTM thiab ASME cov qauv, nrog rau kev xaiv nyob ntawm qhov kev pab cuam. Cov txheej txheem feem ntau yogASTM B 622 Cov khoom lag luam(zoo tib yam rauASME SB-622), uas npog seamless npib tsib xee thiab npib tsib xee-cobalt alloy yeeb nkab rau kev siv corrosion. Rau siab - kev pabcuam siab lossis kub (piv txwv li, boiler lossis siab lub nkoj kav), ASME Tshooj VIII lossis B31.3 cov lej suav nrog SB-622 nrog cov kev xav tau ntxiv.
Rau seamless yeeb nkab npaj rau qaub (H₂S) roj thiab roj kev pab cuam, ua raws liNACE MR0175 / ISO 15156yog yuav tsum tau. Tus qauv no txwv tsis pub muaj kev nyuaj siab (feem ntau Tsawg dua lossis sib npaug li 35 HRC rau C-276) thiab yuav tsum muaj cov kev daws teeb meem tshwj xeeb los tiv thaiv sulfide kev ntxhov siab tawg. Mill daim ntawv pov thawj yuav tsum qhia meej meej txog kev ua raws NACE.
Tsis yog -kev kuaj kev puas tsuaj (NDT) rau seamless yeeb nkab yog nruj.ASTM B 622 Cov khoom lag luamxav kom txhua cov yeeb nkab yuav tsum tau ua ib qho kev sim hydrostatic (qhov ntsuas qhov tsawg kawg nkaus ntsuas los ntawm cov yeeb nkab qhov ntev thiab qhov kev ntxhov siab tso cai) los yog qhov ntsuas tam sim no (ib ASTM E426) ua ke nrog kev sim pneumatic. Rau ntau daim ntawv thov tseem ceeb (nuclear, subsea), cov neeg yuav khoom feem ntau qhia:
Kev kuaj ultrasonic (UT)ntawm tag nrho cov yeeb nkab lub cev txhawm rau txheeb xyuas cov teeb meem sab hauv, laminations, lossis voids (raws li ASTM E213).
Tag nrho - lub cev eddy tam sim norau saum npoo thiab ze ntawm - defects.
Liquid penetrant testing (PT)ntawm ob qhov kawg los xyuas cov kab nrib pleb lossis laminations los ntawm kev txiav thiab ua tiav.
Tsis tas li ntawd, rau cov yeeb nkab seamless uas tau txias txias, agrain loj xeem(ASTM E112) ua kom zoo ib yam zoo -cov qauv zoo.Intergranular corrosion xeemRaws li ASTM G28 Txoj Kev A (ferric sulfate-}sulfuric acid) los yog Txoj Kev B (nitric acid) feem ntau yuav tsum tau ua kom paub tseeb tias cov tshuaj annealing tau zoo thiab tsis muaj qhov tshwm sim. Rau kev txheeb xyuas qhov ntev, kam rau ua raws li ASME B36.19 (stainless steel yeeb nkab qhov ntev) lossis cov qauv siv tshwj xeeb. Cov neeg muab khoom lag luam muaj npe muab cov ntawv pov thawj cov ntaub ntawv pov thawj (MTR) cov ntaub ntawv tshuaj ntsuam xyuas (nrog C, siab Mo, Cr), tensile zog (yield Ntau dua lossis sib npaug rau 355 MPa, tensile Ntau dua lossis sib npaug rau 690 MPa rau C-276), hardness, thiab tag nrho NDT cov txiaj ntsig. Thib peb-kev ua tim khawv rau tog neeg (piv txwv li, Lloyds, DNV, Bureau Veritas) yog ib txwm muaj rau lub hom phiaj tseem ceeb rau kev txiav txim siab seamless yeeb nkab.
