Pickling thiab Passivation ntawm Stainless Hlau

Stainless hlau yog ib qho ntawm cov ntaub ntawv teev tseg tshaj plaws hauv ntiaj teb - siv hauv kev lag luam xws li kev ua zaub mov thiab tshuaj rau roj thiab roj thiab cov vaj tsev facades. Nws cov yam ntxwv txhais yog corrosion kuj, uas tsis yog los ntawm tej hlau nws tus kheej, tab sis los ntawm ib tug nyias, pob tshab txheej ntawm chromium oxide (Cr₂O₃) ntawm nws nto, feem ntau tsuas yog 1-5 nanometers tuab.

Cov txheej txheem passive no yog vim li cas stainless hlau tsis xeb nyob rau hauv ib txwm muaj. Tab sis vuam, kev kho cua sov, kev siv tshuab, thiab kev sib kis tuaj yeem ua rau puas tsuaj los yog ua kom puas. Qhov ntawd yog qhov twgpicklingthiabpassivationtuaj rau hauv. Cov txheej txheem kev kho saum npoo ntawm ob qho no yog qhov tseem ceeb rau kev kho thiab txhim kho corrosion ntawm stainless hlau tom qab fabrication.

Pickling and Passivation of Stainless Steel

Phau ntawv qhia no piav qhia tias txhua tus txheej txheem yog dab tsi, lawv ua haujlwm li cas, thaum twg siv lawv, thiab cov qauv twg tswj hwm lawv - sau kom muaj txiaj ntsig txawm tias koj yog tus kws tshaj lij metallurgist lossis ntsib cov ntsiab lus no thawj zaug.

Kev Pom Kev Pom Zoo: Cov hlau tsis huv uas zoo nkaus li huv ntawm qhov muag liab qab tsis tas yuav muaj corrosion-resistant. Tsis pom cov hlau tsis huv, chromium- thaj chaw depleted, thiab micro- nplai oxide txheej tuaj yeem txo qhov ua tau zoo. Pickling thiab passivation daws cov kev hem thawj uas tsis pom.

Picklingyog cov txheej txheem tshuaj lom neeg saum npoo uas tshem tawm cov nplai, qhov kub thiab txias, oxides, dawb hlau, thiab lwm yam kab mob ntawm cov hlau tsis huv siv cov kua qaub. Nws yog feem ntau siv tom qab vuam, kub- dov, annealing, lossis ib qho txheej txheem thermal uas tawm cov txheej txheem oxide tsis muaj xim - feem ntau hu uakub tintlos yogweld nplai- nyob rau saum npoo hlau.

Pickling of Stainless Steel

Hauv cov ntsiab lus yooj yim: xav txog kev khaws cov tshuaj sib sib zog nqus uas tshem tawm txhua yam tsis xav tau los ntawm cov hlau nto, tawm hauv cov tshuaj lom neeg, nplais -dawb substrate npaj rau passivation lossis kev pabcuam ncaj qha.

Weld tshav kub tint thiab nplai:Xiav, kub, xim av, los yog dub oxide txheej tshwm sim los ntawm vuam cua sov. Cov cheeb tsam no yog chromium-depleted thiab corrosion- nquag.

Dawb hlau thiab embedded hlau hais:Los ntawm cov cuab yeej txiav, sib tsoo, lossis tuav - cov no ua raws li qhov chaw pib corrosion.

Mill scale:Thick hlau oxide txheej tsim thaum kub dov los yog annealing ntawm steel zeb.

Sensitized grain ciam teb:HAZ-induced chromium depletion zones raug tshem tawm ib nrab los ntawm kev tawg ntawm qhov chaw cuam tshuam.

Qhov feem ntau pickling tov rau stainless hlau yog sib tov ntawmNitric acid (HNO ₃)thiabHydrofluoric acid (HF). Cov kua qaub no ua haujlwm sib koom ua ke:

HF:Tawm tsam thiab dissolves hlau oxides thiab chromium-depleted txheej. Nws yog heev txhoj puab heev thiab ua tau zoo ntawm kev tawg scale.

HNO ₃:Oxidizes yaj cov hlau ions, tiv thaiv lawv re-deposition rau saum npoo, thiab pib re-passivation ntawm lub substrate ntxuav.

Cov tshuaj tiv thaiv tshem tawm feem ntau 1-50 µm ntawm cov khoom siv saum npoo av, tshem tawm cov kab mob kis tau zoo thiab nthuav tawm cov tshiab, chromium- nplua nuj stainless hlau nto hauv qab.

Table 1: Pickling Methods rau Stainless Hlau - Sib piv ntawm Cov Ntsiab Cai

Txoj kev	Cov Tshuaj Tseem Ceeb	Kub	Sijhawm tiv tauj	Zoo tshaj rau
Acid da dej / Immersion Pickling	HNO₃ (10–25%) + HF (1–5%)	20-60 degree	10–60 feeb	Daim ntawv, coil, complex qhov chaw
Pickling muab tshuaj txhuam	HNO₃ + HF hauv gel/paste daim ntawv	Ambient	30-120 feeb	Welds, ntawm -site, thaj chaw hauv cheeb tsam
Electrolytic Pickling	H₂SO₄ los yog cov kua qaub sib xyaw + DC tam sim no	40-70 degree	1–10 feeb	Siab- ntim, nruam nruam
Txau Pickling	HNO₃ + HF (diluted)	30-60 degree	5–30 feeb	Loj tiaj tus, tso tsheb hlau luam
Citric Acid Pickling (mob)	Citric acid (5-10%)	50-65 degree	20–60 feeb	Lub teeb scale tshem tawm, eco-tus phooj ywg

Lub sij hawm sib cuag thiab qhov kub thiab txias sib txawv los ntawm qib alloy, ntsuas qhov hnyav, thiab acid concentration. Ib txwm sim ntawm daim coupon ua ntej puv - daim ntawv teev npe. Cov ntaub ntawv raws li kev lag luam- qauv kev coj ua raws li EN ISO 15730 thiab cov txheej txheem kev lag luam.

Passivationyog ib qho tshuaj kho qhov chaw kho mob uas txhim kho lossis kho lub ntuj tsim, tus kheej - kho chromium oxide (Cr₂O₃) passive zaj duab xis ntawm stainless hlau. Tsis zoo li pickling, passivation tsis tshem tawm cov hlau tseem ceeb. Instead, it creates optimal chemical conditions for the chromium in the alloy to preferentially oxidize at the surface, forming a denser, more uniform, and more protective passive layer.

Passivation of Stainless Steel

Hauv cov ntsiab lus yooj yim: yog tias pickling yog qhov sib sib zog nqus huv, passivation yog txheej tiv thaiv tom qab siv. Nws yog cov txheej txheem uas tau muab stainless hlau nws tus yam ntxwv corrosion kuj nyob rau hauv kev pab cuam.

Thaum cov hlau tsis muaj cov pa oxygen (hauv huab cua lossis yaj hauv dej), chromium nyob rau hauv cov alloy reacts nyiam nrog oxygen los ua Cr₂O₃ - zaj duab xis passive. Zaj movie no yog:

Kev kho tus kheej- kho: Yog khawb lossis puas thaum muaj oxygen, nws hloov kho nws tus kheej hauv vib nas this mus rau teev.

Nyias heev: Tsuas yog 1-5 nanometers, tseem muaj txiaj ntsig zoo ntawm kev thaiv kev tawm tsam corrosive.

Chromium-enriched: Qhov saum npoo Cr: Fe piv nyob rau hauv ib tug zoo passivated txheej yog ho siab tshaj nyob rau hauv tej alloy.

Adherent thiab tsis yog - ntxeem tau: Nws tsim ib qho kev thaiv tag nrho ntawm cov hlau thiab nws ib puag ncig.

Ob lub hauv paus tshuaj yog siv rau passivation, txhua tus muaj qhov zoo sib xws:

Nitric Acid Passivation:Cov txheej txheem ib txwm muaj, teev los ntawm ASTM A967 Hom II-VIII. Ua tau zoo thiab nrawm, tab sis tsim cov pa phem nitrous oxide (NOₓ) fumes thiab yuav tsum tau ceev faj tswj cov dej ntws.

Citric Acid Passivation:Ib txoj kev tshiab, ib puag ncig nyiam (ASTM A967 Hom I). Biodegradable, qis toxicity, tsis muaj NOₓ emissions. Sib npaug zoo rau feem ntau qib thiab tam sim no tau txais dav hauv cov khoom noj, tshuaj, thiab kev lag luam semiconductor.

Kev lag luam Trend: Citric acid passivation yog sai sai tshem tawm nitric acid nyob rau hauv ib puag ncig tswj chaw. Kev tshawb fawb xyoo 2022 los ntawm ASTM A967 pawg kws tshaj lij tau pom tias citric acid passivation tam sim no suav txog ntau dua 45% ntawm cov lus qhia tshiab passivation hauv cov khoom noj thiab tshuaj.

Table 2: Pom zoo Passivation Parameters los ntawm Stainless Hlau Qib (ib ASTM A967 / ASTM A380)

SS Qib / Tsev Neeg	Txoj kev Passivation	Acid Concentration	Kub thiab sijhawm	Sau ntawv
304 / 304L	Nitric Acid (ASTM A967 Hom II)	20–25% HNO₃	49 degree, 20 feeb	Txheem qib; nruab nrab passivation
316 / 316L	Nitric Acid (Tib II) los yog Citric (Hom I)	20-25% HNO₃ lossis 4-10% citric	49 degree, 20-30 feeb	Mo cov ntsiab lus pab re-passivation
316L (ultra- qis C)	Citric Acid (nyiam dua)	4-10% yog '	60 degree, 30 feeb	Tsawg-carbon; citric eco-zoo dua
321 / 347 (kwv yees)	Nitric Acid (Tib II)	20–25% HNO₃	54 degree, 30 feeb	Nb/Ti stabilized; ntev da dej
TIAB SA 2205	Nitric Acid (Hom VI)	20–25% HNO₃	54 degree, 20 feeb	Txheeb xyuas ferrite / austenite tshuav nyiaj li cas
Super Duplex 2507	Nitric Acid (Hom VI)	20–25% HNO₃	54 degree, 30 feeb	Siab Cr / Mo; muaj zog passivation
17-4 PHN	Nitric Acid (Tib III)	20–25% HNO₃	49 degree, 30 feeb	Martensitic PH; H2 embrittlement risk
410/420 (martensitic)	Nitric Acid (Tib II)	20–45% HNO₃	54 degree, 30 feeb	Risk ntawm pitting yog hais tias tsis raug rinsed

Parameters sawv cev rau tej yam kev mob pib. Cov txheej txheem tiag tiag yuav tsum tsim nyog raws li tus qauv siv tau. Nco ntsoov sab laj cov ntaub ntawv cov ntaub ntawv thiab txheeb xyuas nrog cov kev xeem passivation zoo. HNO₃=nitric acid; citric=citric acid tov.

Cov ntsiab lus 'pickling' thiab 'passivation' feem ntau tsis meej pem los yog siv sib pauv - tsis raug. Lawv yog cov txheej txheem sib txawv nrog cov txheej txheem sib txawv, sib txawv chemistry, thiab cov txiaj ntsig sib txawv. Cov lus sib piv hauv qab no yog ib qho ntawm cov cuab yeej siv tseem ceeb tshaj plaws hauv phau ntawv qhia no.

Table 3: Pickling vs. Passivation - Ua tiav Sab-los ntawm-Side Comparison

Yam ntxwv	Pickling	Passivation
Lub Hom Phiaj	Tshem tawm nplai, oxides, dawb hlau, HAZ discoloration	Rov qab / txhim kho cov txheej txheem Cr₂O₃
Mechanism	Chemical dissolution ntawm cov kab mob saum npoo	Xaiv oxidation ntawm chromium ntawm qhov chaw
Tshuaj siv	HNO₃ + HF, H₂SO₄ (aggressive acids)	HNO₃ (nruab nrab) lossis citric acid (mob)
Kev tshem tawm nto	Tshem tawm 1-50 µm ntawm cov khoom nto	Tshem tawm<1 µm; no significant metal removal
Thaum siv	Tom qab welding, kub sib sau, los yog annealing	Tom qab machining, pickling, los yog lub teeb kis kab mob
Ib ntus	Ib txwm ua ua ntej passivation (yog tias ob qho tib si xav tau)	Kauj ruam kawg; ua tom qab ntxuav thiab pickling
Kev tshwm sim	Ntxuav, nplai -dawb, matte lossis ci ntsa iab	Chromium-enriched, corrosion{1}}resistant passive zaj duab xis
Ntsiab Standard	EN ISO 15730, ASTM A380 Kev Tswj Xyuas Kev Tswj Xyuas	Txuj: ASTM A967, ASTM A380, AMS 2700
Yuav Siv Tau Ib Leeg?	Yog, rau scale/oxide tshem tawm xwb	Yog, rau lub teeb paug los yog tom qab machining

Ob qho txheej txheem feem ntau ua raws li ntawm tib lub fabrication. Pickling ib txwm yog thawj kauj ruam thaum ob qho tib si xav tau. Passivation tuaj yeem ua tau ib leeg thaum tsuas yog xav tau kev kho lub teeb saum npoo av (xws li, tom qab siv lub tshuab lossis lub teeb paug tsis muaj cua sov).

Nyob rau hauv fabricated assemblies - tshwj xeeb welded Cheebtsam xws li cov hlab ntsha siab, piping systems, thiab heat exchangers - ob qho tib si pickling thiab passivation yog feem ntau yuav tsum tau. Qhov tseeb ua ntu zus yog ib txwm:

Kauj ruam 1 - Ua ntej- ntxuav:Tshem tawm tag nrho cov kab mob, roj, roj, thiab cov khoom xoob siv alkaline degreasing los yog hnyav ntxuav. Cov kauj ruam no tiv thaiv tus da dej pickling los ntawm kev sib kis.

Kauj Ruam 2 - Yaug:Cov dej huv huv (zoo dua deionized) kom tshem tawm cov tshuaj ntxuav.

Kauj ruam 3 - Pickling:Siv cov tshuaj pickling (immersion, muab tshuaj txhuam, los yog tshuaj tsuag) rau lub sijhawm thiab qhov kub thiab txias. Tshem tawm cov nplai, qhov kub thiab txias, thiab tsis muaj hlau.

Kauj Ruam 4 - Yaug kom huv si:Kauj ruam tseem ceeb. Cov kua qaub seem - tshwj xeeb tshaj yog HF - yuav txuas ntxiv tawm tsam cov hlau thiab ua rau qhov chaw puas yog tias tsis tshem tawm tag nrho. Siv ntau theem yaug.

Kauj ruam 5 - Passivation:Siv cov kua qaub passivating (nitric lossis citric) ntawm qhov teev tseg, qhov kub thiab txias, thiab lub sijhawm rau qib alloy.

Kauj ruam 6 - Thaum kawg yaug thiab qhuav:Deionized dej yaug tom qab cua los yog nitrogen kom qhuav. Kev kis kab mob - tsis pub kom qhuav kom tsis txhob muaj dej staining.

Kauj ruam 7 - Kev pov thawj zoo:Kev sim nrog txoj kev tsim nyog (tooj liab sulfate, dej so, ntsuas av) kom paub meej tias kev kho mob ua tiav.

SAFETY CEEB TOOM: Hydrofluoric acid (HF), siv nyob rau hauv pickling, yog heev txaus ntshai. Nws nkag mus rau ntawm daim tawv nqaij yam tsis muaj qhov mob tam sim ntawd thiab tuaj yeem ua rau lub cev toxicity thiab mob plawv. Kov nkaus xwb nrog PPE tag nrho suav nrog cov hnab looj tes nitrile, cov ntaub thaiv npog ntsej muag, thiab cov kua qaub- tiv taus. HF tshuaj tua kab mob (calcium gluconate gel) yuav tsum muaj tam sim ntawd ntawm qhov chaw ua haujlwm. Tsis txhob ua haujlwm nrog HF cov kev daws teeb meem ib leeg.

Ib qho kev kho mob los yog kev kho mob passivation tsuas yog zoo li nws qhov kev txheeb xyuas. Muaj ntau txoj hauv kev ntsuas tus qauv muaj, xws li los ntawm kev kuaj pom yooj yim thiab tshuaj lom neeg mus rau sophisticated electrochemical thiab kev tsom xam cov txheej txheem.

Table 4: Passivation thiab Pickling Quality Verification Tests

Txoj Kev Xeem	Txuj	Dab tsi Nws Pom	Pass Criterion
Kev Ntsuas Dej	ASTM A380 Cov Lus Qhia Tshwj Xeeb	Deg paug / roj	Cov nplooj ntawv dej uniformly (tsis muaj beading)
Copper Sulfate Test	ASTM A380 Cov Lus Qhia Tshwj Xeeb	Dawb hlau ntawm SS nto	Tsis muaj tooj liab deposition tom qab 6 min
High Humidity Test	ASTM A967 Cov Lus Qhia Tshwj Xeeb	General passivation zoo	Tsis muaj xeb tom qab 24 teev ntawm 98% RH, 35 degree
Ntsej Tsuag Test	ASTM B117	Corrosion kuj ntawm zaj duab xis	Tsis muaj xeb liab tom qab 24-200 h (qib- tshwj xeeb)
Ferroxyl Test	Sab hauv / labs	Dawb hlau / hlau paug	Tsis muaj xim xiav tshuaj tiv thaiv
Electrochemical Potentiostat	ASTM G5	Passive tam sim no ceev	Ipass <10 µA / cm² (qhov pib raug)
XPS / AES Surface Analysis	Lab txuj	Cr: Fe ratio ntawm qhov chaw	Cr: Fe piv> 1.0 (enriched Cr txheej)

Kev xaiv xeem nyob ntawm qhov yuav tsum tau ua kom zoo thiab cov qauv siv tau. ASTM A967 qhia txog kev lees paub rau cov av noo, dej raus dej, thiab tshuaj tsuag ntsev. Kev ntsuam xyuas tooj liab sulfate thiab dej tawg yog lub khw muag khoom tshaj plaws - kuaj hauv pem teb. XPS/AES yog tshwj tseg rau R&D lossis siab - daim ntawv thov tseem ceeb.

Kev ua raws li cov qauv lees paub tsis yog xaiv tau nyob rau hauv feem ntau kev lag luam - nws yog ib qho kev cog lus, kev tswj hwm, thiab kev xav tau zoo. Cov lus hauv qab no qhia txog cov qauv uas tau tshaj tawm thoob plaws ntiaj teb.

Table 5: Cov qauv tseem ceeb thoob ntiaj teb rau Stainless Hlau Pickling thiab Passivation

Txuj	Muab Lub Cev	Scope	Cov txheej txheem siv tau
ASTM A380 / A380M ASTM	ASTM Intl.	Ntxuav, descaling, passivation ntawm SS khoom	Pickling + Passivation
ASTM A967 / A967M Kev Cai	ASTM Intl.	Kev kho tshuaj lom neeg rau SS qhov chaw (Types I-VIII)	Passivation (citric thiab nitric)
TIAB SA 2700	SAE UAS	Passivation ntawm corrosion{0}}resistant steels (aerospace)	Passivation
TS EN ISO 15730 Kev Tswj Xyuas Kev Nyab Xeeb	ISO / CEN	Electropolishing thiab tshuaj polishing ntawm SS	Pickling, electropolishing
ASTM B912 Cov Lus Qhia Tshwj Xeeb	ASTM Intl.	Passivation ntawm SS siv electropolishing	Electrolytic passivation
EHEDG Txoj Cai	EHEDG	Hygienic tsim thiab kho deg rau zaub mov/pharma	Pickling + Passivation
NWS M-630	Standards Norway	Cov ntaub ntawv cov ntaub ntawv rau Norwegian roj & roj	Khoom + nto specs
NACE SP0169	NACE Intl.	Tswj kev tiv thaiv sab nraud ntawm cov kav dej	Cov ntsiab lus tiv thaiv corrosion

Cov qauv raug kho tsis tu ncua. Nco ntsoov xyuas tias koj tab tom hais txog tsab ntawv tam sim no. ASTM A967 tau hloov kho tshiab tshaj plaws hauv xyoo 2021 kom suav nrog cov hloov tshiab citric acid passivation hom. AMS 2700 yog thawj aerospace passivation specification hauv North America.

Pickling thiab passivation tsis txwv rau kev lag luam tshwj xeeb. Lawv yog cov qauv kev coj ua thoob plaws txhua qhov haujlwm uas siv cov hlau tsis muaj steel hauv kev thov:

Industry Applications of Stainless Steel

Khoom noj khoom haus thiab dej haus

Cov khoom siv tu cev (lub tank, conveyors, piping) yuav tsum ua tau raws li EHEDG thiab FDA cov qauv rau kev huv huv. Cov hlau dawb lossis nplai hauv cov zaub mov-cov chaw sib cuag tuaj yeem ua rau cov khoom sib kis thiab cov kab mob adhesion. Citric acid passivation yog txoj kev nyiam vim nws cov zaub mov -kev nyab xeeb chemistry. Surface Ra qhov tseem ceeb hauv qab 0.8 µm feem ntau yuav tsum tau ua, ua tiav los ntawm kev sib xyaw nrog cov khoom siv electropolishing.

Pharmaceutical thiab Biotech

USP thiab cGMP ib puag ncig xav tau tshwj xeeb huv si, corrosion- tiv taus qhov chaw. ASTM A270 tswj kev huv huv stainless hlau raj specifications. Cov ntaub ntawv pov thawj Passivation (cov ntaub ntawv pov thawj, cov ntawv xeem, cov ntaub ntawv pov thawj) yog qhov yuav tsum tau kuaj xyuas FDA. Ntau qhov chaw tam sim no siv cov tshuab citric acid passivation tshuab los xyuas kom muaj kev tsim tawm thiab cov ntaub ntawv tag nrho.

Roj, Roj, thiab Petrochemical

Offshore thiab qaub-cov ntawv thov kev pabcuam (qhov twg H₂S nyob) xav tau cov chaw uas ua tau raws li NACE MR0175/ISO 15156 hardness thiab microstructure cov cai. Ncej -weld pickling yog yuav tsum tau rau duplex thiab super duplex stainless hlau pipelines kom tshem tawm rhiab heev-nruj HAZ nplai. NORSOK cov qauv hauv Norwegian txoj cai tswjfwm tau sau cov txheej txheem passivation rau tag nrho cov txheej txheem steel hlau.

Architecture thiab kev tsim kho

Sab nrauv stainless hlau facades, handrails, thiab structural ntsiab yog pickled kom tshem tawm zeb nplai thiab vuam discoloration ua ntej zaum kawg xov. Nyob rau hauv marine los yog ntug dej hiav txwv ib puag ncig, passivation yog ib qho tseem ceeb rau316Llos yog qib duplex kom ua tiav qhov kev cia siab 25–50 xyoo kev pabcuam.

Kev Kho Dej thiab Desalination

Stainless hlau thim rov qab osmosis vaj tse, daim nyias nyias thav duab, thiab cov dej chlorinated yuav tsum tau ua kom tag nrho qhov chaw los tiv thaiv pitting corrosion hauv chloride- cov kwj nplua nuj.Super duplex 2507, thaum xaiv kom raug thiab passivated, ua tiav Critical Pitting Temperature (CPT) qhov tseem ceeb tshaj 70℃hauv kev ntsuas tus qauv.

Siv cov da dej da dej - tshwj xeeb yog HNO₃/HF cov khoom sib tov - raug cais raws li cov khib nyiab pov tseg nyob rau hauv feem ntau cov cheeb tsam (EU Directive 2008/98/EC; US EPA RCRA). Kev pov tseg yuav tsum muaj ntawv tso cai cov neeg ua haujlwm pov tseg. Ntau qhov chaw tau nqis peev hauv cov kua qaub rov ua dua tshiab kom txo tau cov nqi pov tseg thiab kev cuam tshuam ib puag ncig.

Hloov pauv thiab Green Chemistry

Kev tswj hwm lub siab (EU REACH, EPA) yog tsav kev hloov pauv ntawm HF-raws li pickling nrog qis- lwm txoj kev phom sij:

Electrolytic pickling:Tshem tawm HF thiab txo HNO₃ concentration. Tsim kom muaj vaj huam sib luag- cov txiaj ntsig zoo rau feem ntau qib.

Citric acid passivation:Biodegradable, tsis muaj NOₓ emissions, tau yooj yim nruab nrab rau cov dej pov tseg tom qab hloov pH.

Electropolishing:Ib txhij polishes thiab passivates; txo qhov roughness ntawm qhov chaw thiab tshem tawm cov txheej txheem hlau uas tsis muaj HF.

Cov Khoom Siv Tiv Thaiv Tus Kheej (PPE) yuav tsum muaj

Yam tsawg kawg nkaus PPE rau kev ua kua qaub (HNO₃/HF systems) yuav tsum muaj xws li: tag nrho -lub ntsej muag acid splash shield, nitrile los yog neoprene chemical-cov hnab looj tes tiv thaiv (ob npaug- txheej pom zoo), acid- tiv thaiv apron thiab khau looj plab hlaub, yuam- cua tshuab cua nrog cov pa roj carbon monoxide thiab cov pa roj carbon monoxide rov qab. (2.5% calcium gluconate gel) nyob rau hauv caj npab ncav cuag.

CEEB TOOM: HF yog ua raws li kev qhia txog qhov pib raws li OSHA Txheej Txheem Kev Tswj Xyuas Kev Nyab Xeeb (PSM) cov cai (29 CFR 1910.119) ntawm qhov ntau dua 1,000 lbs. Cov chaw siv HF cov ntim tseem ceeb yuav tsum tuav tag nrho PSM qhov kev pab cuam suav nrog cov txheej txheem kev soj ntsuam kev phom sij thiab cov phiaj xwm teb xwm txheej ceev.

Txawm hais tias koj tab tom yuav khoom ua ntej- kho cov khoom tsis muaj steel hlau los yog qhia txog kev kho saum npoo rau cov khoom sib dhos, cov ntawv txheeb xyuas hauv qab no yuav pab xyuas kom koj cov kev xav tau ua tiav:

Buying and Specification Of Stainless Steel Pipe

Qhia tus qauv qhia meej meej:Siv ASTM A967, ASTM A380, lossis AMS 2700 ntawm koj daim duab lossis xaj xaj. Tsis txhob cia siab rau tus neeg muag khoom 'tus qauv kev coj ua.'

Txhais txoj kev xeem:Qhia meej qhov kev kuaj xyuas qhov twg (xws li, tooj liab sulfate, dej so, lossis ntsuas av noo ib ASTM A967) yuav tsum muaj thiab qhov kev lees paub yog dab tsi.

Thov cov ntaub ntawv:Daim ntawv pov thawj passivation qhia txog cov txheej txheem siv, tshuaj lom neeg muaj pes tsawg leeg, lub sijhawm, qhov kub thiab txias, thiab cov txiaj ntsig kev xeem yuav tsum nrog rau txhua qhov khoom xa tuaj.

Paub meej cov ntaub ntawv traceability:Mill test reports (MTRs) yuav tsum txuas mus rau qhov passivated ntau. Cov ntsiab lus carbon (L-qib vs. standard) cuam tshuam rau kev ua haujlwm zoo.

Xav txog qhov chaw pabcuam:Cov qib chloride, qhov kub thiab txias, pH, thiab oxidizing cov neeg ua haujlwm hauv kev pabcuam txhua tus cuam tshuam rau qib passivation zoo. Daim ntawv thov kev tsim vaj tsev ntawm ntug hiav txwv muaj qhov xav tau sib txawv dua li cov tshuaj bioreactor.

Rau nickel alloys:Passivation raws tu qauv txawv heev. Inconel 625 thiab Hastelloy C-276 feem ntau xav tau cov txheej txheem tshwj xeeb uas tsis suav nrog tus qauv ASTM A967. Thov cov ntaub ntawv tshwj xeeb alloy.

Cov Lus Qhia Txog Kev Muag Khoom: Thaum muab cov khoom noj khoom haus thiab cov khoom tsis zoo stainless hlau los ntawm cov mills lossis chaw pabcuam, thov cov ntaub ntawv pov thawj passivation (PPQR) rau koj cov qib tshwj xeeb thiab daim ntawv thov. Cov ntaub ntawv no tau lees paub tias kev kho mob tau raug lees paub ntawm tus neeg sawv cev kuaj daim coupons ua ntej kev tsim khoom, tsis yog xav tias yuav ua haujlwm.

Stainless hlau khwv tau nws lub npe thiab nws cov nqi los ntawm nws cov corrosion kuj. Tab sis qhov kev tawm tsam tsis yog tsis siv neeg. Nws yog tsim nyob rau ntawm qhov chaw - nyob rau hauv ib nanometer- zaj duab xis nyias ntawm chromium oxide uas yuav tsum tau tiv thaiv, rov qab los, thiab xyuas kom meej nyob rau hauv lub fabrication lifecycle.

Pickling tshem tawm qhov vuam, sib sau, thiab tuav tso rau ntawm qhov chaw. Passivation tso rov qab dab tsi ua rau stainless hlau stainless. Ua ke, ob qhov txheej txheem no - txhawb nqa los ntawm cov qauv nruj, txheeb xyuas los ntawm cov kev sim tsim, thiab tswj hwm los ntawm lub luag haujlwm kev nyab xeeb thiab kev coj ua ib puag ncig - yog dab tsi cais cov hlau tsis muaj steel uas kav ntev li kaum xyoo los ntawm ib qho uas ua tsis tiav hauv lub hlis.

Rau engineers, fabricators, thiab procurement cov tub txawg, nkag siab txog pickling thiab passivation tsis yog ib qho khoom kim heev. Nws yog ib qho tseem ceeb uas yuav tsum tau ua kom paub meej, tsim khoom, thiab xa cov khoom siv hlau tsis zoo.