1. Hastelloy B hlau pas nrig yog dab tsi, thiab nws txoj kev tsim khoom txawv li cas ntawm lwm cov ntawv zeb xws li phaj lossis yeeb nkab?
Hastelloy B hlau pas nrig yog ib nrab - tiav, ntev, cylindrical khoom uas ua hauj lwm raws li raw khoom feedstock rau ua tiav cov khoom hlau. Nws yog feem ntau muab rau hauv daim ntawv coiled (kub- dov thiab annealed) nrog cov kab uas hla ntawm kwv yees li 5.5mm (0.217 ") txog 25mm (1").
Txheej txheem tsim khoom vs. Lwm daim ntawv zeb:
Thaum lub phaj ntau lawm cuam tshuam nrog dov ingots rau hauv cov ntawv tiaj tus, thiab cov yeeb nkab ntau lawm suav nrog extruding hollows, hlau qws ntau lawm yog tsom mus rau kev ua tiav cov khoom siv tshwj xeeb thiab qhov zoo rau kev kos duab tom ntej.
Ingot Breakdown: Zoo li phaj thiab yeeb nkab, txheej txheem pib nrog melting thiab casting ingots. Txawm li cas los xij, rau cov hlua hlau, lub ingot yog kub dov rau hauv "billet" (square cross-section) tshwj xeeb tsim rau cov khoom ntev.
Kub Rolling (Rod Rolling): Lub billet yog reheated thiab dhau los ntawm ib tug nruam dov zeb nrog ib tug series ntawm zuj zus me grooves. Qhov no yog lub siab -ceev, thermo- txheej txheem tshuab uas txo cov square billet rau hauv ib puag ncig pas nrig. Cov mills niaj hnub siv "tsis yog-twist" ua tiav cov blocks kom ua tiav qhov sib luag thiab nto tiav ntawm kev kub ceev.
Kev tswj kom txias (Stelmor txheej txheem): Tsis zoo li phaj uas yog quenched, los yog cov yeeb nkab uas yog batch annealed, lub kub -rolled pas nrig yog nteg nyob rau hauv ib ncig ntawm lub conveyor thiab raug tswj kom txias (cua sov los yog dej pos huab). Cov txheej txheem no, feem ntau hu ua Stelmor txheej txheem, hloov cov qauv hlau ua ib qho haum rau kev kos duab txias.
Kev Npaj Nto: Cov pas nrig yog tom qab ntawd muab cov kua qaub (acid ntxuav) kom tshem tawm cov kub - dov oxide nplai (mill scale) thiab tej zaum yuav coated nrog cov roj nplua nyeem (xws li txiv qaub lossis borax) los pab txhawb cov kauj ruam tom ntej.
Vim li cas "Wire Rod" yog qhov txawv:
Nws yog ib qho khoom nruab nrab. Cov neeg siv khoom (ib lub tub rau khoom xaim) siv tus pas nrig no thiab rub nws los ntawm kev tuag (txias kos duab) kom txo nws txoj kab uas hla ntxiv, ua kom nws lub zog tensile (ntawm kev ua hauj lwm hardening), thiab tsim cov hlau kawg siv rau vuam electrodes, springs, los yog mesh. Qhov zoo ntawm tus pas nrig- nws lub suab sab hauv, qhov tsis xws luag, thiab cov nplej loj- ncaj qha txiav txim siab qhov ua tiav ntawm txoj kev kos duab hlau.
2. Nyob rau hauv cov ntsiab lus ntawm fastener ntau lawm, yog vim li cas qhov nto zoo thiab decarburization theem ntawm Hastelloy B hlau pas nrig yog li tseem ceeb?
Thaum tsim cov fasteners xws li bolts, screws, thiab rivets los ntawm Hastelloy B hlau pas nrig, qhov saum npoo ntawm tus pas nrig yog qhov tseem ceeb tshaj qhov tseem ceeb ntawm cov chemistry. Qhov no yog vim qhov saum npoo dhau los ua qhov kev ua haujlwm ntawm cov khoom tiav.
Cov yam tseem ceeb:
Decarburization (Nto Carbon Poob):
Qhov teeb meem: Thaum lub sij hawm kub dov ntawm cov hlau pas nrig, yog hais tias lub billet yog rhuab rau ntev heev los yog nyob rau hauv ib tug oxidizing cua, carbon nyob rau saum npoo yuav hnov mob nrog oxygen thiab depleted. Qhov no tsim ib qho mos, qis - carbon txheej rau ntawm qhov chaw thaum lub hauv paus tseem khaws nws cov hardness.
Qhov tshwm sim hauv Fasteners: Fastener lub zog tso siab rau ntawm cov xov lub peev xwm los tiv thaiv shear quab yuam. Yog hais tias qhov saum npoo yog decarburized, cov xov yuav muaj cov tawv nqaij mos uas hnav tau yooj yim thiab tau txo qis qaug zog. Nyob rau hauv vibration los yog cyclic loading, ib tug tawg yuav pib nyob rau hauv no mos, tsis muaj zog nto txheej thiab propagate, ua rau lub bolt tsis ua hauj lwm. ASTM F788 / F788M qhia txog kev txwv nruj ntawm kev tso cai decarburization rau fasteners.
Defects (Seams, Laps, Cracks):
Qhov Teeb Meem: Kub dov tuaj yeem qee zaum quav hlau hla (laps) lossis tsim cov khawb ntev (seams) yog tias cov yob puas lawm los yog teeb tsa tsis raug.
Qhov tshwm sim hauv Fasteners: Thaum tus pas nrig txias taub hau (smashed rau hauv qhov tuag los tsim lub taub hau taub hau), cov teeb meem saum npoo no ua raws li kev ntxhov siab. Lawv yuav qhib, tsim kev sib cais ntawm lub taub hau los yog tawg ntawm lub shank. Lub fastener yog scrapped tam sim ntawd thaum tsim khoom.
Oxide Scale thiab Pitting:
Residual scale los yog pits los ntawm tsis tsim nyog pickling yuav ua raws li crevices. Hauv kev pabcuam, cov crevices tuaj yeem pib ua haujlwm hauv zos (pitting lossis crevice corrosion), ua rau ua tsis tiav ntxov nyob rau hauv ib puag ncig Hastelloy B tau xaiv los tiv thaiv.
Yog li ntawd, kev yuav khoom tshwj xeeb rau Hastelloy B hlau pas nrig npaj rau fasteners ib txwm suav nrog kev tshuaj xyuas saum npoo (eddy tam sim no lossis pom tom qab pickling) thiab kev kuaj decarburization ntawm ASTM F2328.
3. Hastelloy B hlau qws ua lub luag haujlwm hauv kev tsim cov khoom siv vuam, tshwj xeeb rau Gas Tungsten Arc Welding (GTAW/TIG) rods?
Hastelloy B hlau pas nrig yog thawj cov khoom siv rau kev tsim cov hlau tsis muaj hlau siv hauv Gas Tungsten Arc Vuam (GTAW), tseem hu ua TIG vuam. Nws kuj yog siv rau Gas Hlau Arc Vuam (GMAW/MIG) hlau.
Kev hloov pauv ntawm Qws rau Vuam Hlau:
Cov khoom siv: Cov hlua hlau (feem ntau yog 5.5mm lossis 2.4mm txoj kab uas hla) yog qhov pib.
Cold Drawing: Lub pas nrig yog ntxuav, coated nrog ib tug lubricant, thiab kos los ntawm ib tug series ntawm carbide tuag kom txo tau nws txoj kab uas hla mus rau qhov kawg welding hlau loj (xws li, 1.6mm, 2.0mm, 2.4mm, los yog 3.2mm).
Annealing: Thaum lub sij hawm kos duab, cov hlau ua hauj lwm hardens. Txhawm rau rov ua kom cov ductility xav tau rau kev pub noj kom zoo los ntawm kev sib tw vuam, cov hlau yog tov annealed (rhuab thiab sai quenched) ntawm qhov nruab nrab thiab qhov kawg. Qhov no ua kom cov hlau yog mos txaus kom ncaj thiab noj tsis muaj kinking.
Nto tiav (Cov kauj ruam tseem ceeb): Rau TIG vuam, hlau nto yuav tsum huv thiab du.
Pickling thiab Passivation: Cov hlau yog chemically ntxuav kom tshem tawm cov residual lubricants los yog oxides.
Shaving (xaiv): Rau qhov zoo tshaj plaws "ci" xaim, tus pas nrig yuav shaved (tev) ua ntej kos duab kawg kom tshem tawm cov teeb meem saum npoo, kom ntseeg tau tias tsis muaj qhov tsis zoo uas yuav tsis qhia cov kab mob hauv lub pas dej.
Vim li cas Qws Zoo Matters rau Vuam:
Yog hais tias tus thawj hlau pas nrig muaj inclusions (tsis yog -metallic hais), cov inclusions yuav nyob twj ywm nyob rau hauv lub kawg welding hlau. Thaum cov hlau yog melted rau hauv lub weld sib koom tes, cov inclusions no ua ib feem ntawm cov hlau weld, ua raws li kev ntxhov siab risers thiab pib cov ntsiab lus rau corrosion los yog cracking. Yog li ntawd, vuam hlau ua los ntawm siab- zoo, ultrasonically soj ntsuam pas nrig kom lub suab, huv weld deposits uas phim lub corrosion kuj ntawm lub hauv paus hlau.
4. Dab tsi metallurgical kev txiav txim siab yog tshwj xeeb rau Hastelloy B hlau pas nrig npaj rau lub taub hau txias (tsim cov duab nyuaj), uas tsis yog qhov yooj yim ncaj thiab txiav?
Lub taub hau txias yog qhov siab - nrawm, siab - txoj kev sib sau ua ke siv los tsim cov duab nyuaj xws li lub taub hau taub hau, rivet taub hau, lossis cov ntawv tshwj xeeb yam tsis muaj cua sov rau cov hlau. Hastelloy B hlau pas nrig npaj rau lub taub hau txias yuav tsum muaj cov yam ntxwv tshwj xeeb ntawm cov hlau uas tsis tshua muaj kev cuam tshuam rau cov hlau tsuas yog siv los ua ncaj thiab txiav shafting.
Unique Metallurgical Considerations:
Qhov Loj Loj Loj Loj Loj: Lub taub hau txias muaj kev ntxhov siab (squashing) kawg ntawm cov hlau. Ib coarse grain qauv tuaj yeem ua rau ntxhib, "txiv kab ntxwv tev" nto tiav ntawm lub taub hau tsim. Qhov tseem ceeb tshaj, cov nplej ntxhib tuaj yeem ua rau sib cais raws cov ciam teb nyob rau hauv lub siab compressive. Ib qho zoo, zoo li austenitic grain loj (ASTM 7 los yog finer) yog yuav tsum tau rau cov khoom ntws plastically rau hauv cov kab noj hniav tuag yam tsis muaj cracking.
Kev ywj pheej los ntawm Centerline Segregation: Thaum lub sij hawm ingot solidification, alloying ntsiab (xws li molybdenum) muaj peev xwm qee zaum cais mus rau qhov chaw. Thaum lub billet yog dov rau hauv pas nrig, qhov kev sib cais no tseem yog "centerline" feature. Thaum lub caij txias, qhov nruab nrab ntawm tus pas nrig undergoes tseem ceeb deformation. Yog hais tias qhov chaw yog nkig vim yog kev sib cais, lub taub hau tuaj yeem tso tawm lossis nthuav tawm cov kab nrib pleb.
Tensile thiab Yield Strength Uniformity (Consistent Feedstock): Cov tshuab cua txias ua haujlwm ntawm ntau pua qhov chaw hauv ib feeb. Lawv cia siab rau cov hlau uas muaj lub zog tensile zoo ib yam thiab txoj kab uas hla. Ib qho chaw nyuaj hauv lub kauj tuaj yeem cuam tshuam cov yob pub los yog tawg lub punch. Yog li ntawd, tus pas nrig yuav tsum tau uniformly annealed (spheroidized annealed nyob rau hauv tej rooj plaub) kom zoo ib yam, tsis muaj zog tawm los nyob rau hauv tag nrho cov coil ntev.
Lubricant Carrier Coatings: Rau cov kab mob khaub thuas hnyav, cov hlua hlau feem ntau coated nrog cov roj nplua nyeem tshwj xeeb (xws li tooj liab lossis oxalate coatings) uas ua raws li cov khoom siv hauv cov yeeb yaj kiab hauv cov txheej txheem. Cov pas nrig yuav tsum tau txais cov txheej txheem no.
Hlau pas nrig nkag rau lub taub hau txias yog feem ntau hu ua "Cold Heading Quality" (CHQ) thiab los nrog kev tshuaj xyuas thiab kev soj ntsuam zoo dua piv rau cov qauv hlau pas nrig.
5. Yuav ua li cas qhov zoo ntawm Hastelloy B xaim pas nrig raug txheeb xyuas ua ntej nws siv hauv cov ntawv thov tseem ceeb xws li aerospace lossis kev tsim tshuaj?
Muab hais tias Hastelloy B hlau pas nrig yog ib qho khoom nruab nrab uas yuav hloov mus rau hauv cov khoom tseem ceeb, nws qhov kev kuaj xyuas zoo yog qhov dav thiab ua raws li cov qauv kev lag luam nruj, feem ntau ASTM B335 (Standard Specification for Nickel-Molybdenum Alloy Rod, Bar, thiab Hlau).
Quality Verification Protocols:
Kev Ntsuam Xyuas Tshuaj (Kev Ntsuam Xyuas ntawm UNS N10665):
Txoj kev: Optical Emission Spectroscopy (OES) los yog cov tshuaj ntub dej tshuaj ntsuam xyuas ntawm txhua qhov cua sov.
Cov ntsiab lus tseem ceeb: Molybdenum cov ntsiab lus (26-30%), Hlau (2% max), thiab cov khoom seem zoo li Chromium (1% max) raug txheeb xyuas kom ntseeg tau tias "B-2" chemistry.
Mechanical Testing:
Tensile thiab Yield Strength: Ua kom cov pas nrig ua tau raws li qhov yuav tsum tau muaj zog tsawg kawg nkaus.
% elongation thiab txo ntawm cheeb tsam: Kev ntsuas ductility, uas yog qhov tseem ceeb rau kev kos duab los yog tsim.
Hardness: Tshawb xyuas kom muaj kev sib haum xeeb thiab tsim nyog rau kev ua haujlwm txias.
Tsis yog -Kev Tshawb Fawb Kev Ua Phem (NDE):
Ultrasonic Testing (UT) rau ASTM E213: Rau txoj kab uas hla loj dua, UT yog siv los tshuaj xyuas tag nrho tus ntoo khaub lig-section rau sab hauv voids, tawg, los yog inclusions uas yuav ua rau tsis ua hauj lwm thaum lub sij hawm kos duab.
Eddy Current Testing (ET) per ASTM E309: Rau cov kab me me, eddy tam sim no yog siv los ua ib qho kev soj ntsuam ceev ceev kom pom cov laps, seams, lossis tawg.
Kev ntsuam xyuas Microstructural:
Grain Size (ASTM E112): Tshawb xyuas kom ntseeg tau tias nws tsim nyog rau daim ntawv thov (zoo nplej rau lub taub hau txias).
Inclusion Cleanliness (ASTM E45): Cov pas nrig tau tshuaj xyuas nyob rau hauv lub tshuab ntsuas qhov ntsuas kom muaj nuj nqis thiab hom tsis yog -hlau inclusions (sulfides, oxides, silicates). Qhov ntsuas "huv" (cov ntsiab lus tsis tshua muaj nyob hauv) yog xav tau rau siab - daim ntawv thov kev ncaj ncees.
Decarburization Check (ASTM E1077): Rau cov pas nrig npaj rau fasteners lossis threading, qhov saum npoo raug kuaj xyuas kom tsis txhob muaj cov pa roj carbon poob thaum kub dov.
Kev kuaj Corrosion (yeem tab sis pom zoo):
Rau kev pabcuam tshuaj lom neeg tseem ceeb, cov qauv ntawm cov pas nrig cua sov tuaj yeem raug rau ASTM G28 Txoj Kev A los xyuas kom meej tias cov txheej txheem kub dov thiab annealing tsis hnov tsw cov khoom thiab nws ua tau raws li qhov yuav tsum tau muaj kev tiv thaiv corrosion.
Thaum dhau qhov kev ntsuam xyuas no, tus pas nrig tau lees paub nrog Daim Ntawv Qhia Txog Mill Test (MTR) lossis Daim Ntawv Pov Thawj Ua Raws Cai, traceable rov qab mus rau qhov qub cua sov, muab cov neeg siv kawg nrog kev ntseeg siab ntawm cov khoom siv.
