1. ASTM B574 UNS N06022 yog dab tsi, thiab nws cov ntsiab lus chromium siab npaum li cas pab tau zoo tshaj plaws hauv oxidizing acid ib puag ncig?
Teb:
ASTM B574 UNS N06022, feem ntau hu ua Hastelloy C-22, yog npib tsib xee-chromium-molybdenum alloy nrog tungsten tseem ceeb ntxiv, tsim kom muaj kev tiv thaiv tshwj xeeb rau oxidizing thiab txo cov kua qaub. Round bars tsim rau ASTM B574 los ntawm cov hlau no tau teev tseg rau cov kev xav tau tshaj plaws ntawm kev siv tshuaj lom neeg, tshwj xeeb tshaj yog qhov chaw oxidizing predominate.
Tshuaj muaj pes tsawg leeg (A ASTM B574):
| Element | Qhov hnyav% |
|---|---|
| Nickel (Ni) | Tshuav |
| Chromium (Cr) | 20.0 - 22.5 |
| Molybdenum (hli) | 12.5 - 14.5 |
| Tungsten (W) | 2.5 - 3.5 |
| Hlau (Fe) | 2.0 - 6.0 |
| Cobalt (zeeg) | Tsawg dua lossis sib npaug li 2.5 |
| Cov pa roj carbon (C) | Tsawg dua lossis sib npaug li 0.015 |
| Silicon (Si) | Tsawg dua lossis sib npaug li 0.08 |
| Manganese (Mn) | Tsawg dua los yog sib npaug li 0.50 |
| Vanadium (V) | Tsawg dua lossis sib npaug li 0.35 |
Cov yam ntxwv tseem ceeb ntawm Compositional:
High Chromium (20-22.5%):
Muab kev tiv thaiv tshwj xeeb rau oxidizing acids (nitric acid, ferric ions, cupric ions).
Ua kom ruaj khov, tiv thaiv Cr₂O₃ oxide zaj duab xis.
Qhov tseem ceeb tshaj C-276 (14.5-16.5%), ua C-22 qhov kev xaiv zoo tshaj plaws rau oxidizing ib puag ncig.
Molybdenum (12.5-14.5%):
Muab kev tiv thaiv zoo heev los txo cov kua qaub (hydrochloric, sulfuric).
Txhim khu kev tiv thaiv rau localized corrosion (pitting, crevice corrosion).
Tungsten Ntxiv (2.5-3.5%):
Muab cov tshuaj tiv thaiv kom muaj zog.
Txhim khu kev tiv thaiv rau cheeb tsam corrosion, tshwj xeeb tshaj yog nyob rau hauv ib puag ncig chloride.
Txhim kho siab -qhov kub thiab txias.
Ultra-Cov pa roj carbon tsawg (tsawg dua lossis sib npaug rau 0.015%):
Minimizes carbide nag lossis daus thaum vuam.
Qhov tseem ceeb rau kev tswj xyuas qhov sib txawv corrosion kuj nyob rau hauv raws li -welded mob.
Hlau tswj (2-6%):
Sib npaug cov nqi thiab kev ua haujlwm.
Muab cov tshuaj tiv thaiv kom muaj zog.
Vim li cas C-22 Excels hauv Oxidizing Ib puag ncig:
Cov ntsiab lus chromium siab (20-22.5%) muab C-22 qhov txiaj ntsig zoo hauv oxidizing acids xws li nitric acid, qhov chaw ruaj khov chromium oxide zaj duab xis yog qhov tseem ceeb rau kev tiv thaiv. Qhov no ua rau C-22 qhov kev xaiv zoo tshaj plaws ntawm C-tsev neeg alloys thaum ib puag ncig feem ntau oxidizing lossis hloov pauv ntawm oxidizing thiab txo cov mob.
Sib piv rau Lwm C-Tsev Neeg Alloys:
| Alloy | UNS | Cr% | Mo% | W % | Lub zog tseem ceeb |
|---|---|---|---|---|---|
| C-22 | N06022 | 20-22.5 | 12.5-14.5 | 2.5-3.5 | Qhov zoo tshaj plaws oxidizing kuj, ntau yam |
| C-276 | N10276 | 14.5-16.5 | 15-17 | 3-4.5 | Universal, tsim cov ntaub ntawv |
| C-2000 | N06200 | 22-24 | 15-17 | - | Qhov zoo tshaj plaws sulfuric acid kuj (nrog Cu) |
| C-4 | N06455 | 14-18 | 14-17 | - | Siab thermal stability |
| 625 | N06625 | 20-23 | 8-10 | - | Siab zog, dej hiav txwv |
2. Dab tsi yog cov ntawv thov tseem ceeb rau ASTM B574 UNS N06022 round bars hauv kev lag luam tshuaj lom neeg, tshuaj, thiab tswj kev ua qias tuaj?
Teb:
ASTM B574 UNS N06022 round bars tau teev tseg rau daim ntawv thov uas yuav tsum tau tshwj xeeb tsis kam rau oxidizing acids thiab sib xyaw ib puag ncig. Cov ntsiab lus siab chromium ua rau cov hlau no tshwj xeeb tshaj yog muaj txiaj ntsig nyob qhov twg oxidizing tej yam kev mob.
Kev Siv Tshuaj Siv Tshuaj:
Kev Pabcuam Nitric Acid:
Kev Ua Haujlwm: Cov khoom xyaw hauv cov nroj tsuag nitric acid, kev ua haujlwm pickling, thiab cov txheej txheem nitration.
Vim li cas C-22 Bars: High chromium (20-22.5%) muab tshwj xeeb tsis kam rau oxidizing nitric acid ntawm txhua qhov ntau.
Cov Cheebtsam: Twj shafts, valve stems, agitator shafts, fasteners, heat exchanger Cheebtsam.
Oxidizing Chloride Ib puag ncig:
Muaj nuj nqi: Cov khoom xyaw hauv cov txheej txheem nrog cov tshuaj chlorides thiab oxidizing hom (bleach nroj tsuag, pulp thiab ntawv).
Vim li cas C-22 Bars: High chromium resists oxidizing tej yam kev mob; molybdenum thiab tungsten tiv thaiv chloride pitting.
Cov khoom xyaw nquag: Tov khoom shafts, scraper hniav, fasteners.
Mixed Acid Service:
Muaj nuj nqi: Cov khoom xyaw hauv cov txheej txheem cuam tshuam nrog kev sib xyaw ntawm oxidizing thiab txo cov kua qaub.
Vim li cas C-22 Bars: Qhov sib npaug sib npaug ua haujlwm hloov pauv tau zoo heev.
Cov Cheebtsam: Reactor agitator shafts, valve Cheebtsam, instrumentation.
Flue Gas Desulfurization (FGD) Systems:
Muaj nuj nqi: Cov khoom xyaw hauv cov tshuaj txhuam hniav tuav cov tshuaj chlorides, fluorides, thiab oxidizing tej yam kev mob.
Vim li cas C-22 Bars: Kev tiv thaiv zoo heev rau kev txhim kho hauv cheeb tsam hauv cheeb tsam chloride aggressive.
Cov Cheebtsam: Cov tshuaj tsuag nozzles, agitator shafts, txhawb cov qauv, fasteners.
Pharmaceutical Industry Applications:
API Synthesis Reactor Cheebtsam:
Muaj nuj nqi: Agitator shafts, baffle kev txhawb nqa, thiab ntsuas hauv nitration reactors.
Vim li cas C-22 Bars: Resistant aggressive nitrating acids; tiv thaiv cov hlau tsis huv.
High -Purity Water Systems:
Kev Ua Haujlwm: Cov Cheebtsam hauv WFI (Dej rau Txhaj) cov tshuab nrog cov tshuaj tua kab mob oxidizing.
Vim li cas C-22 Bars: Kev tiv thaiv zoo rau ozone, hydrogen peroxide, thiab lwm yam tshuaj tua kab mob.
Daim Ntawv Thov Kev Tiv Thaiv Kev Ua Txhaum Cai:
Waste Incineration Systems:
Muaj nuj nqi: Cheebtsam nyob rau hauv lub kaw lus tuav corrosive combustion khoom.
Vim li cas C-22 Bars: Resistant complex mixs of acids at high temperatures.
Kev kho dej khib nyiab:
Kev Ua Haujlwm: Cov khoom siv hauv cov tshuab nrog oxidizing biocides (chlorine, chlorine dioxide).
Vim li cas C-22 Bars: High chromium muab kev tiv thaiv rau oxidizing biocides.
Lwm yam kev siv:
| Kev lag luam | Daim ntawv thov | Cheebtsam Machined los ntawm Bar |
|---|---|---|
| Nuclear Roj Processing | Cov kev daws teeb meem | HNO ₃/HF mix |
| Hlau Refining | Acid leaching nrog oxidizers | Pump shafts, agitators |
| Pulp thiab ntawv | Bleach cog khoom siv | Mixer shafts, fasteners |
| Mining | Siab oxidation hlab ntsha | Agitator Cheebtsam |
Tej Cheebtsam Machined los ntawm C-22 Round Bars:
| Cheebtsam | Bar Size Range | Machining kev ua haujlwm |
|---|---|---|
| Pump Shafts | 0.5" - 10" diam | Tig, sib tsoo, keyway txiav |
| Valve Stems | 0.25" - 6" diam | Tig, threading, sib tsoo |
| Fasteners | 0.125" - 4" diam | Xov dov / txiav, taub hau |
| Thermowells | 0.5" - 3" diam | Qhov tob qhov drilling, tig |
| Agitator Ncej | 1" - 12" diam | Tig, keyway txiav |
| Scraper Hniav | Flat bar machined los ntawm puag ncig | Milling, sib tsoo |
Case Study: Nitric Acid Plant Valve Stems
Ib tsob nroj nitric acid tau ntsib kev xeb sai ntawm 316L stainless hlau valve stems hauv 67% HNO₃ ntawm qhov kub siab. Stems yuav tsum tau hloov txhua 3-4 lub hlis. Hloov stems machined los ntawm ASTM B574 UNS N06022 puag ncig tuav txuas ntxiv kev pab cuam lub neej tshaj 5 xyoos, nrog tsawg kawg corrosion pom. Cov ntsiab lus siab chromium muab qhov tsim nyog oxidizing tsis kam.
3. Dab tsi machining yam ntxwv yog tshwj xeeb rau ASTM B574 UNS N06022 puag ncig tuav, thiab cov khw yuav ua li cas txhim kho qhov tsis zoo rau kev tsim khoom zoo?
Teb:
Machining ASTM B574 UNS N06022 round bars nthuav tawm cov teeb meem ntawm nickel-chromium- molybdenum alloys, tab sis nws cov khoom sib npaug tso cai rau kev ua tiav nrog cov txheej txheem tsim nyog. Cov ntsiab lus siab chromium muab qee cov txiaj ntsig hauv kev tsim nti piv rau siab dua - molybdenum alloys.
Kev txiav txim siab txog kev coj tus cwj pwm:
Nruab nrab mus rau siab zog:
Annealed tensile zog: 100-110 ksi (690-760 MPa) raug.
Yuav tsum muaj cov cuab yeej siv tshuab nruj thiab siab dua txiav quab yuam.
Yield zog: 45-55 ksi raug.
Ua Haujlwm Hardening:
Ua hauj lwm hardens thaum lub sij hawm machining, feem ntau ntawm nickel alloys.
Tsawg nruj dua li siab -molybdenum alloys.
Qhov cuam tshuam: Yuav tsum txiav hauv qab ua haujlwm- txheej tawv tawv; zam kev txiav lub teeb.
Tsawg Thermal conductivity:
Thaum tshav kub kub generated ntawm tej cheeb tsam nyob twj ywm concentrated.
Ua rau cov cuab yeej siab kub, ua kom cov cuab yeej siv nrawm nrawm.
Qhov cuam tshuam: Yuav tsum tau ua kom txias thiab cua sov- cov ntaub ntawv tiv taus.
Chip Tsim:
Ua tau tawv tab sis tswj tau chips.
Kev tswj cov nti zoo dua li qee qhov siab -molybdenum alloys.
Qhov cuam tshuam: Chip breakers tseem tseem ceeb.
Ua -Up Edge (BUE):
Nruab nrab nyiam rau cov khoom siv vuam mus rau txiav ntug.
Qhov cuam tshuam: Cov cuab yeej ntse, nrawm nrawm / pub, thiab cov khoom ua kom txias yog qhov tseem ceeb.
Optimization Strategies:
Kev xaiv cuab yeej:
| Kev ua haujlwm | Pom zoo cov cuab yeej siv | Geometry |
|---|---|---|
| Tig (rough) | Carbide (C-2 qib), coated (TiAlN / AlTiN) | Zoo rake, ntse ntug, chip breaker |
| Tig (tiav) | Carbide, cermet rau kev ua tiav zoo | Wiper inserts, ntse ntug |
| Milling | Carbide, siab - feed cutters | Zoo geometry |
| Drilling | Carbide, cobalt HSS rau qhov me me | Split point, coolant los ntawm |
| Tapping | Daim ntawv kais nyiam; txiav kais tau txais | Ntsej muag, zoo -lubricated |
| Xov | Xov milling lossis ib zaug -point | Ntau lub teeb hla |
Txiav Parameters:
| Kev ua haujlwm | Ceev (SFM) | Pub (IPR) | Qhov tob ntawm Txiav |
|---|---|---|---|
| Tig (rough) | 50-90 | 0.008-0.015 | 0.050-0.150" |
| Tig (tiav) | 70-110 | 0.003-0.008 | 0.010-0.030" |
| Milling | 50-90 | 0.002-0.005 PIB | 0.020-0.100" |
| Drilling | 25-45 | 0.002-0.005 PAB | Peck lub voj voog |
| Tapping (form) | 10-20 | Matches xov suab | N/A |
Coolant thiab Lubrication:
Dej nyab qhov tseem ceeb; siab -siab los ntawm- cov cuab yeej muaj txiaj ntsig.
Siv dej- cov kua dej ua kua dej nrog EP additives.
Rau tapping thiab threading, xav txog tshwj xeeb tapping compounds.
Ua kom tiav cov dej txias kom tswj tau cov cua sov thiab dej ntws tawm.
Toolpath Strategies:
Ua kom muaj kev sib koom tes tas li yog tias ua tau.
Tsis txhob nyob hauv tsev lossis rub.
Climb milling nyiam los txo cov haujlwm hardening.
Xav txog kev ua haujlwm siab -milling rau roughing.
Kev ua haujlwm:
Rigid teeb tseem ceeb.
Hydraulic los yog precision mechanical chucks.
Txhawb nqa ntev ntev nrog kev so ruaj khov.
Surface Finish Capabilities:
| Kev ua haujlwm | Hom Achievable tiav |
|---|---|
| Rough tig | 63-125 Ib |
| Ua kom tiav | 16-32 Ib |
| Precision tig | 8-16 Ib |
| Sib tsoo | 4-8 Ib |
Common Challenges thiab Solutions:
| Kev sib tw | Kev daws |
|---|---|
| Cov cuab yeej hnav | Optimize ceev, coated carbides, txaus txias |
| Qhov chaw tsis zoo | Ua kom ceev, txo cov khoom noj, cov cuab yeej ntse |
| Chip tswj | Chip breaker inserts, siab -pressure coolant |
| Ua hauj lwm hardening | Khaws cov khoom noj, zam kev txiav lub teeb |
| Kev vibration | Ua kom rigidity, txo overhang |
Qhov zoo tshaj qhov siab dua -Molybdenum Alloys:
C-22 cov ntsiab lus qis dua me ntsis ntawm molybdenum (12.5-14.5% vs . 15-17% hauv C-276) tuaj yeem muab kev ua haujlwm zoo dua qub thaum tswj kev ua haujlwm zoo corrosion. Qhov no ua rau nws yog ib qho kev xaiv zoo rau cov khoom siv uas yuav tsum tau siv cov machining.
4. Dab tsi yog kev tswj hwm thiab ntawv pov thawj uas yuav tsum tau siv rau ASTM B574 UNS N06022 round bars rau cov ntawv thov tseem ceeb?
Teb:
ASTM B574 UNS N06022 round bars rau cov ntawv thov tseem ceeb yuav tsum muaj kev tswj xyuas zoo thiab ua tiav daim ntawv pov thawj kom ntseeg tau tias cov khoom siv ruaj khov, tiv thaiv corrosion, thiab ntev - lub sij hawm cia siab. Cov kev cai no feem ntau tshaj cov qauv ASTM specifications.
Tswj Specifications:
| Txuj | Title | Daim ntawv thov |
|---|---|---|
| ASTM B574 | Nickel Alloy pas nrig, Bar, thiab Hlau | Cov khoom tseem ceeb specification |
| ASTM B880 Cov Lus Qhia Tshwj Xeeb | General Requirements rau Nickel Alloy Qws, Bar, thiab Hlau | Cov kev xav tau ntxiv |
| ASME Section II, Part B | SIB-574 | ASME Boiler & Pressure Vessel Code |
| NACE MR0175/ISO 15156 | Petroleum thiab natural gas industries | Cov kev pabcuam qaub |
| TIAB SA 400 | German technical standard | High -kev siv kub |
Cov ntaub ntawv pov thawj yuav tsum muaj:
Mill Test Report (MTR):
Certified tshuaj ntsuam xyuas ib lub tshav kub.
Kev txheeb xyuas cov cuab yeej cuab tam (tensile, yield, elongation).
Kev kho cua sov daim ntawv pov thawj.
Traceability los ntawm yaj mus rau tiav bar.
Thaum tshav kub kub Traceability:
Txhua bar cim nrog tus lej kub.
Daim ntawv qhia ntawm cov tuav rau cov cua sov tshwj xeeb khaws cia.
Positive Material Identification (PMI):
Feem ntau xav tau rau cov ntawv thov tseem ceeb.
Txheeb xyuas qib ntawm txhua qhov bar (100% kev soj ntsuam ntau).
X-ray fluorescence (XRF) lossis optical emission spectroscopy (OES).
Chemical Composition Verification (ASTM B574):
| Element | Kev xav tau (%) |
|---|---|
| Nickel | Tshuav |
| Chromium | 20.0 - 22.5 |
| Molybdenum | 12.5 - 14.5 |
| Tungsten | 2.5 - 3.5 |
| Hlau | 2.0 - 6.0 |
| Cobalt | Tsawg dua lossis sib npaug li 2.5 |
| Cov pa roj carbon | Tsawg dua lossis sib npaug li 0.015 |
| Silicon | Tsawg dua lossis sib npaug li 0.08 |
| Manganese | Tsawg dua los yog sib npaug li 0.50 |
| Vanadium | Tsawg dua lossis sib npaug li 0.35 |
Mechanical Property Verification:
| Khoom | Annealed Requirement |
|---|---|
| Tensile zog | 100 ksi (690 MPa) min |
| Yield zog (0.2% offset) | 45 ksi (310 MPa) min |
| Elongation | 45% min |
Tsis yog -Kev Tshawb Fawb Kev Ua Phem (NDE):
| Txoj kev | Daim ntawv thov | Lub Hom Phiaj |
|---|---|---|
| Kev kuaj ultrasonic (UT) | Loj diameters, kev siv tseem ceeb | Inclusions, voids, tawg |
| Eddy Current Testing (ET) | Cov kab me me, kev tshuaj xyuas saum npoo | Nto seams, laps, tawg |
| Cov kua dej Penetrant (PT) | Bar xaus, xav tias thaj chaw | Nto tawg, laps |
| Visual Examination (VT) | 100% ntawm bar nto | Surface defects, finish quality |
Dimensional soj ntsuam:
| Parameter | Kev kam rau siab (rau ASTM B574) | Kev ntsuas ntsuas |
|---|---|---|
| Txoj kab uas hla | +0.000", -0.005" to -0.020" (loj nyob ntawm) | Micrometer, calipers |
| Ntev | +0.125" rau +0.250", -0" | Daim kab xev ntsuas |
| Kev ncaj | 1/8 "hauv 3 ko taw (tseem) | Straightedge, feeler gauge |
| Nto tiav | Raws li tau teev tseg (feem ntau 63-125 Ra) | Kev pom, profileometer |
| Ovality | Nyob rau hauv txoj kab uas hla kam rau ua | Calipers, micrometer |
Kev kuaj Corrosion:
ASTM G28 Txoj Kev A:
Lub hom phiaj: Tshawb xyuas qhov cuam tshuam rau intergranular corrosion.
Ib puag ncig: Boiling ferric sulfate-sulfuric acid.
Txais: Corrosion rate Tsawg dua lossis sib npaug li 0.5 hli / xyoo raug.
ASTM G28 Txoj Kev B:
Lub hom phiaj: Ntsuam xyuas kev tiv thaiv corrosion.
ASTM G48 (Pitting kuj):
Lub hom phiaj: Ntsuam xyuas kev tiv thaiv pitting corrosion.
Ib puag ncig: Ferric chloride tov.
Yam yuav tsum tau muaj: Tsis muaj pitting ntawm 25℃rau 24 teev.
Kev kuaj tshwj xeeb rau cov ntawv thov tseem ceeb:
| Kuaj | Lub hom phiaj | Yam yuav tsum tau muaj |
|---|---|---|
| Loj Loj | Txheeb xyuas cov txheej txheem microstructure | ASTM 5-8 rau ASTM E112 |
| Inclusion Rating | Kev ntsuas kev huv | Raws li ASTM E45 |
| Kev Tshawb Fawb Hardness | Txheeb xyuas qhov sib xws | Tsis pub dhau qhov txwv |
| Microstructural Examination | Txheeb xyuas cov theem kom raug | Tsis muaj kev puas tsuaj los nag |
| NWS TM0177 | Sulfide kev nyuaj siab tawg | Rau kev pabcuam qaub |
| Kev ntsuam xyuas cuam tshuam | Xyuas kom toughness | Charpy V-notch ntawm qhov ntsuas kub |
Cov ntaub ntawv pob:
| Cov ntaub ntawv | Cov ntsiab lus |
|---|---|
| Certified Mill Test Report | Chemistry, mechanicals, kho cua sov |
| NDE Reports | UT, ET, PT cov txiaj ntsig |
| Dimensional Inspection Report | Ntsuas qhov ntev |
| PMI Report | Kev txheeb xyuas qib |
| Corrosion Test Reports | ASTM G28, G48 cov ntsiab lus |
| NACE ua raws | Yog muaj |
| Daim Ntawv Pov Thawj Ua Raws Cai | Specification ua raws |
Cov Lus Cog Tseg:
ASTM B574
Qib (UNS N06022)
Loj (inch × ntev)
Kub naj npawb
Tus neeg tsim khoom lub npe
Lub teb chaws ntawm keeb kwm
5. Yuav ua li cas cov ntsiab lus siab chromium ntawm UNS N06022 txhim kho nws cov kev ua tau zoo hauv oxidizing ib puag ncig, thiab cov kev txwv ntawm alloy yog dab tsi?
Teb:
Lub ntsiab lus ntawm UNS N06022 (C-22) yog nws cov ntsiab lus chromium siab (20-22.5%), uas ua rau muaj txiaj ntsig zoo hauv oxidizing ib puag ncig piv rau lwm yam C-tsev neeg alloys. Kev nkag siab txog qhov zoo thiab cov kev txwv yog qhov tseem ceeb rau kev xaiv cov khoom tsim nyog.
Mechanism ntawm Chromium Enhancement:
Oxidizing Acid Resistance:
Chromium tsim ib qho ruaj khov, tiv thaiv Cr₂O₃ oxide zaj duab xis rau ntawm qhov chaw.
Cov yeeb yaj kiab no yog qhov tseem ceeb rau kev tiv thaiv oxidizing acids zoo li nitric acid.
Cov ntsiab lus chromium siab dua ua rau muaj kev ruaj khov dua, tiv thaiv zaj duab xis ntau dua.
Critical Pitting Kub (CPT):
Cov chromium siab dua ua rau qhov tseem ceeb pitting kub hauv qhov chaw chloride.
C-22 feem ntau muaj CPT siab dua C-276 hauv ntau qhov chaw.
Passive Range Extension:
Chromium txuas ntxiv qhov ntau ntawm qhov muaj peev xwm tshaj qhov uas cov hlau tseem nyob tsis tau.
Qhov no txhais tau tias zoo dua tiv thaiv hauv zos corrosion nyob rau hauv ib puag ncig sib xyaw.
Kev ua tau zoo hauv Oxidizing Ib puag ncig:
| Ib puag ncig | C-22 kev ua haujlwm | Sib piv rau C-276 |
|---|---|---|
| Nitric acid (tag nrho cov conc.) | Zoo heev | Zoo heev |
| Ferric chloride hmoov | Zoo heev | Zoo dua |
| Cupric chloride | Zoo heev | Zoo dua |
| Oxidizing chlorides | Zoo heev | Zoo dua |
| Kev sib xyaw acids (oxidizing) | Zoo heev | Zoo dua |
Kev ua tau zoo hauv Kev Tshaj Tawm Tshwj Xeeb:
| Nruab nrab | Nco ntsoov | Kub | Corrosion tus nqi (mpy) |
|---|---|---|---|
| Nitric Acid | 65% | Boiling | <1 |
| Nitric Acid | 70% | 150℃F | <1 |
| Ferric Chloride | 10% | 150℃F | <1 (no pitting) |
| Chlorine Dioxide | Bleach tsob nroj | Txheej txheem | Zoo heev |
Qhov zoo dua lwm cov alloys:
| Alloy | Oxidizing kuj | Txo qhov tsis kam | Localized Corrosion |
|---|---|---|---|
| C-22 | Zoo tshaj plaws ntawm C- tsev neeg | Zoo heev | Zoo heev |
| C-276 | Zoo | Zoo heev | Zoo heev |
| C-2000 | Zoo heev | Qhov zoo tshaj plaws (nrog Cu) | Zoo heev |
| 625 | Zoo heev | Nruab nrab | Zoo |
Kev txwv ntawm C-22:
Sulfuric Acid (Intermediate Concentrations):
Thaum zoo, C-22 tsis yog qhov kev xaiv zoo tshaj plaws rau sulfuric acid hauv 40-60%.
C-2000 (nrog tooj liab) ua tau zoo tshaj C-22 hauv qhov chaw tshwj xeeb no.
High Oxidizing Potentials:
Cov xwm txheej oxidizing heev (ntse nitric acid nrog chromates) yuav nyuaj txawm tias C-22.
Tshwj xeeb alloys (xws li zirconium) tej zaum yuav xav tau rau huab oxidizing tej yam kev mob.
Kub txwv:
Qhov kev pabcuam kub siab tshaj plaws nyob ntawm ib puag ncig.
Tshaj 800℃F, txhua yam khoom txo qis.
Halide txwv:
Thaum zoo heev, tsis tiv thaiv pitting hauv huab cua chloride ib puag ncig ntawm qhov kub siab heev.
Tus nqi:
hwm alloy; kim kim tshaj stainless hlau.
Designer's Checklist:
| Kev txiav txim siab | Kev ua |
|---|---|
| Oxidizing ib puag ncig tam sim no? | C-22 yog qhov kev xaiv zoo dua |
| Sulfuric acid intermediate conc. | Xav txog C-2000 hloov |
| Cov kua qaub sib xyaw? | C-22 kev xaiv zoo heev |
| Chlorides nrog oxidizers? | C-22 yog qhov zoo tagnrho |
| Kub hauv qhov txwv? | Tshawb xyuas rau cov xwm txheej tshwj xeeb |
Case Study: Nitric Acid Cooler Cheebtsam
Ib tsob nroj tshuaj uas tsim tau 65% nitric acid tau ntsib kev xeb ntawm C-276 cov khoom siv hluav taws xob. Corrosion tus nqi ntawm 2-3 mpy tau txais tab sis txwv. Hloov nrog C-22 Cheebtsam txo qhov corrosion mus rau<0.5 mpy, extending service life from 5 years to over 15 years. The higher chromium content provided the necessary improvement in oxidizing acid resistance.
