Cov tshooj ob tshooj no qhia txog cov ntsiab lus tseem ceeb ntawm tsab xov xwm ntawm electropolishing thiab saib ua ntej Tverberg qhov kev nthuav qhia ntawm InterPhex tom qab lub hlis no. Niaj hnub no, nyob rau hauv Part 1, peb yuav tham txog qhov tseem ceeb ntawm electropolishing stainless hlau kav, electropolishing cov txheej txheem, thiab analytical txoj kev. Nyob rau hauv qhov thib ob, peb nthuav tawm cov kev tshawb fawb tshiab ntawm passivated mechanically polished stainless hlau kav.
Ntu 1: Electropolished Stainless Steel Tubes Cov kws tshuaj thiab cov khoom lag luam semiconductor xav tau ntau cov electropolished stainless hlau raj. Nyob rau hauv ob qho tib si, 316L stainless hlau yog cov nyiam alloy. Stainless hlau alloys nrog 6% molybdenum yog qee zaum siv; alloys C-22 thiab C-276 yog ib qho tseem ceeb rau semiconductor manufacturers, tshwj xeeb tshaj yog thaum gaseous hydrochloric acid yog siv raws li ib tug etchant.
Yooj yim txheeb xyuas qhov tsis xws luag ntawm qhov chaw uas yuav txwv tsis pub lub npog ntsej muag ntawm qhov tsis sib xws ntawm qhov chaw pom hauv cov khoom siv ntau dua.
Cov tshuaj inertness ntawm cov txheej passivating yog vim qhov tseeb tias ob qho tib si chromium thiab hlau nyob rau hauv 3+ oxidation lub xeev, thiab tsis yog zerovalent hlau. Mechanically polished nto khaws cov ntsiab lus siab ntawm cov hlau dawb hauv zaj duab xis txawm tias tom qab ntev thermal passivation nrog nitric acid. Qhov tseem ceeb no ib leeg muab cov khoom siv electropolished zoo dua nyob rau hauv cov nqe lus ntawm kev ruaj ntseg mus sij hawm ntev.
Lwm qhov sib txawv tseem ceeb ntawm ob qhov chaw yog qhov muaj (hauv cov khoom siv polished) lossis tsis tuaj (hauv electropolished nto) ntawm cov khoom alloying. Mechanically polished nto tuav lub ntsiab alloying muaj pes tsawg leeg nrog me ntsis poob ntawm lwm yam alloying ntsiab, thaum electropolished nto muaj feem ntau tsuas yog chromium thiab hlau.
Ua cov kav dej electropolished Kom tau txais ib qho chaw electropolished, koj yuav tsum pib nrog ib tug du nto. Qhov no txhais tau hais tias peb pib nrog cov hlau zoo heev, tsim rau qhov zoo tshaj plaws weldability. Kev tswj yog tsim nyog thaum melting sulfur, silicon, manganese thiab deoxidizing ntsiab xws li txhuas, titanium, calcium, magnesium thiab delta ferrite. Lub sawb yuav tsum tau kho cua sov kom yaj cov theem ob uas yuav tsim tau thaum lub sij hawm yaj solidification los yog tsim thaum kub kub.
Tsis tas li ntawd, hom kab txaij tiav yog qhov tseem ceeb tshaj plaws. ASTM A-480 teev peb cov khoom lag luam muaj cov kab mob khaub thuas ua tiav: 2D (cua annealed, pickled, thiab blunt dov), 2B (cua annealed, yob pickled, thiab yob polished), thiab 2BA (ci annealed thiab shield polished). huab cua). rolls).
Profiling, vuam thiab hloov hlaws yuav tsum tau ua tib zoo tswj kom tau txais lub raj ntau tshaj plaws. Tom qab polishing, txawm me ntsis undercut ntawm weld los yog ib txoj kab ncaj nraim ntawm cov hlaws yuav pom. Tsis tas li ntawd, tom qab electropolishing, cov kab ntawm dov, dov qauv ntawm welds thiab txhua yam kev puas tsuaj rau saum npoo yuav pom tseeb.
Tom qab kev kho cua sov, lub puab txoj kab uas hla ntawm cov yeeb nkab yuav tsum tau mechanically polished kom tshem tawm qhov tsis xws luag ntawm nto tsim thaum lub sij hawm tsim ntawm lub sawb thiab cov yeeb nkab. Nyob rau theem no, kev xaiv ntawm kab txaij tiav ua qhov tseem ceeb. Yog tias qhov quav tob dhau lawm, cov hlau ntau dua yuav tsum tau muab tshem tawm ntawm qhov chaw ntawm sab hauv ntawm lub raj kom tau lub raj du. Yog hais tias qhov roughness yog ntiav los yog tsis muaj, tsawg hlau yuav tsum tau muab tshem tawm. Qhov zoo tshaj plaws electropolished tiav, feem ntau nyob rau hauv 5 micro-inch ntau lossis smoother, yog tau los ntawm longitudinal band polishing ntawm cov hlab. Hom polishing no tshem tawm feem ntau ntawm cov hlau los ntawm qhov chaw, feem ntau nyob rau hauv 0.001 nti ntau, yog li tshem tawm cov ciam teb, qhov tsis zoo ntawm qhov chaw, thiab tsim cov teeb meem. Whirling polishing tshem tawm cov khoom siv tsawg dua, tsim "ntoo" nto, thiab feem ntau ua rau ntau dua Ra (qhov nruab nrab ntawm qhov roughness) hauv 10-15 microinch ntau.
Electropolishing Electropolishing tsuas yog rov qab txheej. Ib qho tshuaj electropolishing yog pumped hla lub puab kab ntawm lub raj thaum lub cathode yog kos los ntawm lub raj. Cov hlau yog nyiam dua los ntawm cov ntsiab lus siab tshaj plaws ntawm qhov chaw. Cov txheej txheem "cia siab" rau galvanize lub cathode nrog hlau uas yaj hauv lub raj (piv txwv li, anode). Nws yog ib qho tseem ceeb los tswj cov electrochemistry kom tsis txhob muaj cov txheej txheem cathodic thiab tswj qhov tseeb valency rau txhua ion.
Thaum lub sij hawm electropolishing, oxygen yog tsim rau ntawm qhov chaw ntawm lub anode los yog stainless hlau, thiab hydrogen yog tsim nyob rau saum npoo ntawm cathode. Oxygen yog cov khoom tseem ceeb hauv kev tsim cov khoom tshwj xeeb ntawm electropolished nto, ob qho tib si los ua kom qhov tob ntawm txheej passivation thiab tsim kom muaj tseeb passivation txheej.
Electropolishing tshwm sim nyob rau hauv lub thiaj li hu ua "Jacquet" txheej, uas yog ib tug polymerized nickel sulfite. Txhua yam uas cuam tshuam nrog kev tsim ntawm Jacquet txheej yuav ua rau muaj qhov tsis zoo electropolished nto. Qhov no feem ntau yog ion, xws li chloride lossis nitrate, uas tiv thaiv kev tsim ntawm nickel sulfite. Lwm cov khoom cuam tshuam yog cov roj silicone, roj, waxes thiab lwm cov saw hlau ntev hydrocarbons.
Tom qab electropolishing, cov hlab tau ntxuav nrog dej thiab ntxiv passivated nyob rau hauv kub nitric acid. Qhov no passivation ntxiv yog tsim nyog los tshem tawm cov seem ntawm cov nickel sulfite thiab txhim kho qhov chaw chromium rau hlau piv. Tom qab passivated raj tau ntxuav nrog cov txheej txheem dej, muab tso rau hauv dej kub deionized, qhuav thiab ntim. Yog tias yuav tsum tau ntim cov chav huv huv, cov tubing tseem yaug hauv cov dej deionized kom txog rau thaum cov txheej txheem tau teev tseg, ces qhuav nrog cov nitrogen kub ua ntej ntim.
Cov txheej txheem ntau tshaj plaws rau kev txheeb xyuas qhov chaw electropolished yog Auger electron spectroscopy (AES) thiab X-ray photoelectron spectroscopy (XPS) (tseem hu ua chemical tsom xam electron spectroscopy). AES siv cov khoom siv hluav taws xob tsim nyob ze ntawm qhov chaw los tsim cov teeb liab tshwj xeeb rau txhua lub ntsiab lus, uas muab faib cov ntsiab lus nrog qhov tob. XPS siv cov hluav taws xob xoo hluav taws xob uas tsim kev sib khi, tso cai rau cov hom molecular kom paub qhov txawv ntawm lub xeev oxidation.
Tus nqi nto roughness nrog ib tug deg profile zoo ib yam li cov saum npoo zoo li tsis txhais hais tias tib yam nto. Feem ntau cov niaj hnub profilers tuaj yeem tshaj tawm ntau qhov sib txawv ntawm qhov sib txawv ntawm qhov sib txawv, suav nrog Rq (tseem hu ua RMS), Ra, Rt (qhov sib txawv siab tshaj plaws ntawm qhov tsawg kawg nkaus thiab qhov siab tshaj plaws), Rz (qhov nruab nrab qhov siab qhov siab), thiab ob peb lwm qhov tseem ceeb. Cov kab lus no tau txais los ntawm ntau yam kev suav nrog ib zaug dhau ib ncig ntawm qhov chaw nrog lub cwj mem pob zeb diamond. Hauv qhov kev hla no, ib feem hu ua "cutoff" yog xaiv los ntawm hluav taws xob thiab kev suav ua raws li qhov no.
Surfaces tuaj yeem piav qhia tau zoo dua los ntawm kev sib txuas ntawm cov qauv tsim muaj txiaj ntsig xws li Ra thiab Rt, tab sis tsis muaj ib qho kev ua haujlwm uas tuaj yeem paub qhov txawv ntawm ob qhov chaw sib txawv nrog tib tus nqi Ra. ASME tshaj tawm ASME B46.1 tus qauv, uas txhais lub ntsiab lus ntawm txhua qhov kev suav ua haujlwm.
Yog xav paub ntxiv hu rau: John Tverberg, Trent Tube, 2015 Zog Dr., PO Box 77, East Troy, WI 53120. Xov tooj: 262-642-8210.