Ib qho txuas txuas ntxiv ntawm lub teeb ci, stainless hlau xaim, tsim rau kev kho mob tseem ceeb lossis kev siv dav hlau, yog kos los ntawm qhov kub, fuming da dej ntawm nitric thiab hydrofluoric acid kom tshem tawm cov oxides thiab nplai. Lub immersion rhaub uas sov no corrosive pickle yuav tsum tau raws li chemically tawv raws li cov kua qaub nws tus kheej, thiab nws yuav tsum tsis txhob tso ib tug hlau ion mus rau lub ntxuav hlau, vim hais tias tej qhov chaw deg yuav pib ib tug corrosion pit.

Txoj Kev Pickling rau Stainless Hlau Hlau

Tom qab kub sib sau, annealing, los yog kos duab, stainless hlau hlau tsim ib tug tenacious txheej ntawm oxide nplai (chromium-nplua nuj oxides thiab sib tov hlau spinels). Qhov ntsuas no yuav tsum tau muab tshem tawm ua ntej xaim tuaj yeem ua tiav lossis siv rau hauv daim ntawv thov rhiab. Txoj kev zoo tshaj plaws yogpicklingNyob rau hauv ib tug kub sib tov ntawm nitric acid (HNO₃) thiab hydrofluoric acid (HF).

Ib tug zoo pickling da dej muaj:

10-20% nitric acid- ua raws li tus neeg sawv cev oxidizing, passivating lub hauv paus stainless hlau nto.

1-4% hydrofluoric acid- aggressively tawm tsam cov oxide nplai thiab yooj yim rau nws dissolution.

Ua haujlwm kub:50-70 degree- tuav tsis tu ncua raws li cov xaim tau kos los ntawm lub da dej.

Ntawm qhov ntsuas kub no, cov tshuaj tiv thaiv cov tshuaj tiv thaiv tau zoo, thiab cov nplai raug tshem tawm tsis tu ncua hauv lub sijhawm luv luv (thib ob mus rau feeb). Cov da dej rhuab ua kom lub teeb ci, huv si, thiab tsis sib xws ntawm cov hlau xaim.

Yog vim li cas lub PTFE rhaub yog tib txoj kev ntseeg siab

Cov cua kub sib xyaw cov tshuaj nitric-hydrofluoric acid nthuav tawm cov khoom nyuaj heev. Txawm tias high-alloy stainless steels (piv txwv li, Hastelloy C-276, Inconel) raug kev kub ntxhov intergranular nres thiab pitting nyob rau hauv HF-muaj ib puag ncig, tshwj xeeb tshaj yog nyob rau hauv siab kub. Hlau-sheathed immersion heaters yuav leach hlau, chromium, thiab nickel ions rau hauv da dej. Cov ions no tuaj yeem tso rau ntawm cov hlau nto, tsim cov chaw rau pitting corrosion tom qab los yog cuam tshuam cov txheej txheem passive. Rau kev kho mob-qib lossis aerospace hlau, xws li kev sib kis tsis tuaj yeem lees txais.

CovPTFE rhaub stainless hlau xaim picklingCov tshuaj yog PTFE-sheathed immersion rhaub. Polytetrafluoroethylene (PTFE) tiv thaiv tag nrho cov nitric thiab hydrofluoric acids nyob rau hauv 50-70℃kev khiav hauj lwm ntau yam. Lub PTFE sheath tsis hnov ​​​​mob nrog da dej, tsis nqus cov kua qaub, thiab tso tawm raws nraim xoom hlau ions mus rau hauv lub pickle. Lub du, tsis-stick nto kuj tiv thaiv kev tsim cov hlau fluoride sludge (xws li hlau fluoride, chromium fluoride) uas precipitates raws li lub hnub nyoog siv acid. Cov cuab yeej tu tus kheej no ua kom cov cua sov hloov pauv tau zoo thiab txo cov sijhawm txij nkawm.

Lub PTFE lub rhaub yog ib qho tshuaj tsis pom kev, muaj qhov sov so hauv qhov sib tov sib xyaw, tsis ntxiv ib yam dab tsi tab sis cov cua sov uas xav tau los ntxuav cov hlau yam tsis muaj ib qho tsis xav tau atom qab.

Muab Uniform, ruaj khov rau cov hlau zoo ib yam

Qhov zoo ntawm cov hlau pickled nyob ntawm qhov kub thiab txias uniformity. Cov chaw txias hauv chav da dej ua kom tsis tiav qhov kev tshem tawm, ua rau tsaus nti, streaky, lossis tsis tiav cov xaim tsis tiav. Overheated zones ua kom cov kua qaub noj, ua kom muaj pa ntau dhau, thiab tuaj yeem nyob hauv zos over-pickle cov hlau nto, ua rau roughness lossis hydrogen absorption.

PTFE immersion rhaub yog tsim los nrog ntau yam, sib npaug spaced cua sov ntsiab lus. Lub PTFE sheath muab qhov tsawg-watt-density nto (feem ntau 3-5 W / cm²) uas faib cov cua sov sib npaug rau hauv chav da dej yam tsis muaj qhov chaw kub kub. Qhov no maj mam, niaj hnub cua sov tswj tag nrho cov pickling tank ntawm qhov xav tau setpoint ± 2 degree, kom ntseeg tau tias txhua lub meter ntawm cov xov hlau tau ntsib tib yam tshuaj. Qhov tshwm sim yog ib qho zoo ib yam, ci, thiab zoo kawg nkaus huv hlau nto ntawm qhov pib mus rau qhov kawg.

Txheej Txheem Lus Cim: Kev nyab xeeb thiab ntim rau Hydrofluoric Acid

Hydrofluoric acid yog tshuaj lom heev thiab ua rau muaj kev nyab xeeb tshwj xeeb. Txawm tias dilute HF cov kev daws teeb meem tuaj yeem nkag mus rau ntawm daim tawv nqaij thiab ua rau qhov sib sib zog nqus, mob kub hnyiab uas yuav tsis hnov ​​​​mob tam sim ntawd. Yog li ntawd, txhua qhov kev teeb tsa pickling siv HF yuav tsum suav nrog kev ntsuas kev nyab xeeb.

Rau lub rhaub PTFE siv hauv qhov kev pabcuam no, yuav tsum muaj ob qho kev qhia tseem ceeb:

Qhov cua zoo heev:Lub tank pickling yuav tsum tau muab ntim rau hauv lub fume hood los yog nruab nrog ib tug cross-flow scrubber system kom ntes HF thiab NOₓ fumes tso tawm thaum cua sov thiab xaim nkag.

Secondary ntim rau lub rhaub flange:Lub PTFE sheath nws tus kheej yog tshuaj inert, tab sis cov hluav taws xob kev twb kev txuas flange (feem ntau yog ib tug PTFE-encapsulated hlau txiav) yuav tsum tau tiv thaiv los ntawm cov kua qaub los yog spillage. Ib lub khob ntim khoom thib ob lossis cov ntaub thaiv npog yog ntsia ib ncig ntawm lub flange. Yog hais tias lub da dej puas dhau los lossis lub tshuab rhaub tau muab tshem tawm thaum tseem nyob hauv dej, cov kua qaub uas ntws tawm sab nraud ntawm lub plhaub tau ntes tau hauv qhov ntim thiab muaj kev nyab xeeb rov qab mus rau hauv lub tank lossis mus rau qhov dej nruab nrab. Qhov no tiv thaiv cov neeg ua haujlwm raug thiab cov khoom puas tsuaj.

Tsis tas li ntawd, txhua qhov kev saib xyuas ntawm lub rhaub lossis cov kab pickling yuav tsum tau ua tsuas yog tom qab lub rhaub tau txias thiab lub tank tau ntws los yog nruab nrab. Cov ntaub ntawv kaw tseg / tagout thiab cov khoom siv tiv thaiv tus kheej muaj kua qaub (PPE) yog qhov yuav tsum tau ua.

Lub PTFE rhaub ua ib qho me me tab sis tseem ceeb

Nyob rau hauv high-speed stainless hlau xaim pickling kab, PTFE immersion rhaub feem ntau yog ib feem ntawm kaum ob. Txawm li cas los xij nws lub luag haujlwm tseem ceeb. Yog tsis muaj kev ntseeg siab, tsis muaj paug tsis muaj cua sov, lub da dej pickling tsis tuaj yeem tswj hwm nws qhov kub thiab txias, ua rau kev tshem tawm tsis sib xws thiab tsis lees txais cov hlau. Nrog lub tshuab hluav taws xob hlau-sheathed, qhov kev pheej hmoo ntawm kev sib kis ntawm qhov chaw yuav kov yeej lub hom phiaj ntawm pickling - los ua ib qho chaw huv, tsis muaj zog.

Lub PTFE rhaub ua haujlwm ntsiag to, feem ntau tau ntau xyoo, nyob rau hauv cov tshuaj phem tshaj plaws uas tau ntsib hauv kev ua cov hlau. Nws cov khoom tsis yog-stick tiv thaiv sludge tsub zuj zuj, thiab nws cov hluav taws xob rwb thaiv tsev tseem nyob zoo txawm tias tsis tu ncua raug rau cov kua qaub kua qaub. Kev tshuaj xyuas ib ntus (kev kuaj megger thiab kev kuaj pom pom kev puas tsuaj) thiab hloov cov gaskets ntawm lub flange tsuas yog cov haujlwm uas yuav tsum tau ua.

Xaus: Lub Purity ntawm tshav kub txhais tau qhov zoo ntawm cov hlau

PTFE immersion rhaub yog qhov tseem ceeb, tshuaj tiv thaiv kab mob, thiab tsis muaj kab mob rau cov cua sov rau pickling stainless hlau hlau. Nws ua kom muaj qhov tsis muaj qhov tsis zoo, tsis sib xws ntawm qhov chaw rau cov ntawv thov xav tau tshaj plaws -los ntawm kev phais phais mus rau lub dav hlau cable. Qhov zoo ntawm cov hlau tseem ceeb ntawm lub neej pib tsis yog los ntawm kev kos duab tuag lossis lub qhov cub tawg, tab sis nrog lub purity ntawm cov cua sov hauv nws chav da dej. Los ntawm kev xaiv lub tshuab cua sov PTFE nrog cov ntaub ntawv sau tseg thiab txhim kho nws nrog qhov tsim nyog thib ob ntim thiab qhov cua, cov kws tshaj lij nto moo tuaj yeem ua tiav zoo ib yam, muaj txiaj ntsig zoo thaum tiv thaiv cov khoom lag luam thiab kev nyab xeeb ntawm tus neeg teb xov tooj. Nyob rau hauv lub ntiaj teb corrosive ntawm HF-HNO₃ pickling, PTFE lub rhaub tsis yog ib qho kev xaiv xwb- nws yog tus qauv txhim khu kev qha xwb.