Ob leeg316 ib 321yog austenitic stainless hlau nrog roughly tib chromium (16-18%) thiab nickel (10-14%) cov ntsiab lus. Qhov sib txawv los mus rau ib qho kev sib ntxiv ntawm txhua qhov:
316L muaj 2.0-3.0% molybdenum. Qhov molybdenum yog dab tsi muab 316L nws tsis kam rau pitting thiab crevice corrosion nyob rau hauv ib puag ncig chloride. Nws tseem yog dab tsi ua rau 316L kim dua 321 hauv ntau lub khw.
321 muaj titanium, ntxiv ntawm qhov tsawg kawg nkaus ntawm 5 x C% (cov ntsiab lus carbon). Cov titanium txuas cov pa roj carbon monoxide li titanium carbide, tiv thaiv chromium carbide nag lossis daus ntawm cov ciam teb thaum cov hlau kub ntawm 425 thiab 900 degrees Celsius. Qhov no yog hu ua stabilization, thiab nws yog vim li cas 321 tuaj yeem ua haujlwm ntawm qhov kub thiab txias qhov twg 316L, txawm tias nws qis - carbon daim ntawv, pib tawm tsam.
Cov Khoom Muag Khoom
Bar & Rod
Phaj & Ntawv
Coil & Sawb
Tube & Tube
Haum: Flange, Tee, Luj Tshib, Reducer thiab lwm yam.
Forging: Nplhaib, Ncej, Vajvoog, Thaiv thiab lwm yam.
| Element | 316L (%) | 321 (%) |
|---|---|---|
| Chromium | 16.0 - 18.0 | 17.0 - 19.0 |
| Nickel | 10.0 - 14.0 | 9.0 - 12.0 |
| Molybdenum | 2.0 - 3.0 | -- |
| Titanium | -- | 5 x C min, 0.70 max |
| Cov pa roj carbon | 0.035 max | 0.08 max |
| Manganese | max 2.00 Nws | max 2.00 Nws |
| Silicon | 0.75 max | 0.75 max |
| Phosphorus | 0.045 max | 0.045 max |
| Sulfur | 0.030 max | 0.030 max |
Corrosion resistance: qhov twg 316L khwv tau nws cov nqi
Yog tias koj qhov chaw pabcuam muaj cov tshuaj chlorides, 316L yog qhov kev xaiv zoo dua. Cov ntsiab lus molybdenum nce qhov sib npaug sib npaug ntawm tus lej (PREN) mus rau ib puag ncig 22-25, piv rau li 17-19 rau 321. Hauv cov ntsiab lus siv tau, qhov no txhais tau tias 316L resists pitting hauv dej hiav txwv, dej brackish, thiab cov txheej txheem chloride-cov kabmob hauv zos uas 321 yuav pib tawm tsam.
Qhov tseem ceeb pitting kub (CPT) qhia zaj dab neeg hauv cov lej. Hauv tus qauv 3.5% NaCl tov rau ASTM G150,316LFeem ntau qhia CPT nyob ib ncig ntawm 25-30 degrees Celsius. Rau 321, CPT yog ze rau 15-20 degrees. Nyob rau hauv lub ntiaj teb Gulf seawater ntawm 35 degrees Celsius thiab salinity siab, tsis yog qib zoo tagnrho rau kev sib cuag dej hiav txwv ncaj qha (uas yog qhov twg super duplex qib zoo li SAF 2507 lossis 254 SMO tuaj), tab sis 316L yuav muaj sia nyob thaj tsam txaws thiab huab cua raug ntev dua 321.
Kev ntxhov siab corrosion cracking (SCC) yog lwm hom tsis ua hauj lwm tsim nyog hais. Ob qib no raug rau cov tshuaj chloride SCC siab tshaj 60 degrees Celsius hauv cov tshuaj chloride-cov kabmob ib puag ncig. 316L tsis txhais tau tias ua tau zoo tshaj 321 ntawm no. Yog tias koj qhov kev pabcuam kub siab tshaj 60 degrees hauv ib puag ncig chloride thiab koj tsis tuaj yeem tshem tawm cov chlorides, koj yuav tsum tau saib cov qib duplex lossis super austenitic, tsis xaiv ntawm ob qho no.
Qhov twg321tuav nws tus kheej yog nyob rau hauv oxidizing acid ib puag ncig ntawm siab kub. Sulfuric acid nyob rau hauv nruab nrab concentrations, nitric acid kev pab, thiab tej yam petrochemical txheej txheem kwj qhov kub yog qhov tseem ceeb kev sib tw es chloride nres. Lub titanium stabilization tiv thaiv intergranular corrosion nyob rau hauv lub tshav kub- cuam tshuam thaj chaw tom qab vuam, uas tseem ceeb hauv cov kev pab cuam acid qhov twg grain ciam teb nres yog thawj tsis ua hauj lwm mechanism.
High -kev ua haujlwm kub: rooj plaub rau 321
Qhov no yog qhov uas 321 muaj qhov tseeb, ntsuas tau zoo. ASME Boiler thiab Pressure Vessel Code (Section VIII, Division 1) tso cai rau 321 rau kev pabcuam kub txog 816 degrees Celsius. Rau 316L, txoj cai txwv hauv kev pabcuam txuas ntxiv yog nyob ib puag ncig 450 degrees Celsius, txawm hais tias kev pabcuam cuam tshuam rau 425 degrees yog qhov ntau.
Qhov laj thawj yog carbide nag lossis daus. Txawm tias muaj cov ntsiab lus carbon tsawg ntawm 316L, lub sijhawm ntev tshaj li 425 degrees tso cai rau chromium carbides tsim ntawm cov ciam teb, depleting thaj chaw uas nyob ib sab ntawm chromium thiab tsim ib txoj hauv kev rau intergranular corrosion thaum hlau yog tom qab raug corrosive xov xwm. Lub titanium hauv 321 tiv thaiv qhov no los ntawm kev nyiam ua titanium carbide, tawm hauv cov chromium hauv kev daws.
Cov ntawv thov tiag tiag qhov twg 321 yog txoj cai hu:
- Cov pa hluav taws xob thiab manifolds ua haujlwm ntawm 600-800 degrees
- Thaum tshav kub kub exchanger raj hauv catalytic cracker units
- Cov khoom siv hluav taws xob thiab cov khoom siv hluav taws xob hluav taws xob
- Kev nthuav dav pob qij txha thiab lub hauv siab hauv siab -kub ducting
- Aerospace pa paug thiab afterburner Cheebtsam
Vuam thiab fabrication: 316L yog ntau zam txim
Ob qib yog weldable los ntawm cov txheej txheem austenitic: GTAW (TIG), GMAW (MIG), SMAW (stick), thiab SAW. Tab sis kev paub fabrication txawv.
316L yog qib yooj yim rau kev ua haujlwm nrog hauv khw lossis chaw teeb tsa. Cov ntsiab lus carbon tsawg txhais tau tias koj tuaj yeem txuas nws yam tsis muaj kev txhawj xeeb txog kev hnov mob hauv tshav kub- thaj chaw cuam tshuam, thiab koj tsis tas yuav xa tawm -weld tov annealing los kho corrosion kuj. Filler hlau xaiv yog ncaj nraim: ER316L rau feem ntau daim ntaub ntawv, los yog ER316LSi yog tias koj xav tau zoo wetting thiab ib tug smoother hlaws profile.
321 xav tau kev saib xyuas ntxiv. Cov titanium uas ruaj khov qib kuj cuam tshuam rau lub pas dej ua ke. Titanium muaj kev sib raug zoo rau cov pa oxygen, thiab nyob rau hauv lub pas dej molten weld nws tuaj yeem tsim cov titanium oxide inclusions uas tshwm sim li slag-zoo li qhov tsis xws luag yog shielding gas coverage tsis nruj. ER347 muab tub lim (niobium-stabilized) feem ntau siv tsis yog ER321 vim li no. Niobium muab tib txoj haujlwm ruaj khov yam tsis muaj qhov nyuaj vuam uas titanium qhia.
Rau cov yeeb nkab - mus rau - yeeb nkab pob tw welds ib ASME B16.9, ob qib weld zoo nrog cov txheej txheem tsim nyog. Qhov teeb meem tshwm sim ntau dua nyob rau hauv txoj kev weldments nrog ntau qhov kev hla, nruj kev sib koom ua ke, los yog kev sib txuas ntawm qhov chaw uas cua thiab paug yog yam tseem ceeb. Yog tias koj qhov fabrication muaj ntau qhov chaw vuam lossis qhov chaw ua haujlwm, 316L yuav ua rau koj cov welder tsis mob taub hau.
Formability zoo ib yam ntawm ob qib. Ob leeg tuaj yeem khoov, flared, thiab nthuav dav siv cov txheej txheem austenitic forming txheej txheem . 321 tuaj yeem nyuaj me ntsis rau txias - daim ntawv vim yog titanium carbonitride particles ua rau kev ua haujlwm hardening, tab sis qhov sib txawv me me rau feem ntau cov yeeb nkab thiab cov ntawv thov haum.
Rau pob tw-weld fittings (lub luj tshib, tees, reducers ib ASME B16.9 thiab B16.28), ob qib yog muaj los ntawm cov khoom muag feem ntau. Txawm li cas los xij, 316L fittings feem ntau yuav muaj nyob rau hauv Tshuag, thaum 321 fittings yuav tsum tau txiav txim nrog lub sij hawm ntev dua, tshwj xeeb tshaj yog nyob rau hauv qhov loj me los yog tsis yog - cov txheej txheem.
| Specification | 316L | 321 |
|---|---|---|
| ASTM / ASME (US) | A312 TP316L / A403 WP316L / A182 F316L | A312 TP321 / A403 WP321 / A182 F321 |
| EN (Tebchaws Europe) | 1.4404 | 1.4541 |
| JIS (Nyiv) | SUS 316L | SUS 321 |
| GOST (Russia/CIS) | 03Ch17N14M 2 | 08 Tx18N10T |
| GB (Tuam Tshoj) | 022Cr17Ni12Mo2 | 06Cr18Ni11 Ti |
Cov lus qhia txog kev yuav khoom uas txuag nyiaj thiab tsis txhob muaj teeb meem
Tshawb xyuas daim ntawv pov thawj zeb xeem rau titanium cov ntsiab lus ntawm 321 xaj.Qee lub mills tsim 321 nrog titanium ntawm qhov tsawg kawg nkaus (5 x carbon). Yog tias cov pa roj carbon nyob rau ntawm qhov siab kawg ntawm qhov ntau (0.06-0.08%), titanium yuav tsum yog tsawg kawg yog 0.30-0.40%. Yog hais tias titanium yog marginal thiab cov pa roj carbon ntau, lub stabilization yuav tsis zoo. Nug rau kev suav: Ti / (4 x C) yuav tsum siab dua 1.0 kom ruaj khov tag nrho.
Qhia qhov kev xa khoom.316L yeeb nkab feem ntau yog muab rau hauv cov kev daws teeb meem -annealed mob. 321 tuaj yeem muab annealed lossis stabilized-annealed. Lub stabilized-annealed mob (tuav ntawm 900-950 degrees rau 1-2 teev) maximizes titanium carbide tsim thiab txhim kho intergranular corrosion kuj. Yog tias koj daim ntawv thov cuam tshuam nrog vuam ua raws li kev pabcuam corrosive, qhia kom ruaj khov-annealed.
Tsis txhob xav tias 316L thiab 321 tuaj yeem hloov pauv tau rau cov lej- raws li daim ntawv thov.Yog tias tus qauv tsim tau ua tiav rau 316L (nrog nws qhov tshwj xeeb tso cai rau kev ntxhov siab ntawm ASME Tshooj II, Ntu D), hloov 321 yuav tsum rov ua dua -xyuas cov txiaj ntsig kev ntxhov siab ntawm qhov ntsuas kub. Nyob rau ntawm 400 degrees, 321 muaj ib tug me ntsis qis tso cai kev nyuaj siab tshaj 316L. Ntawm 600 degrees, 321 yog siab dua vim 316L tsis yog code- ntsuas ntawm qhov ntsuas kub txhua.
Rau pob tw -weld fittings, xyuas cov qhab nias.Fittings yuav tsum tau cim nrog qib, tus lej xov tooj cua sov, thiab cov chaw tsim khoom lub cim ntawm ASME B16.9. WP316L thiab WP321 fittings zoo tib yam. Yog tias koj lub tsev khaws khoom muaj ob qho tib si, xim coding lossis cais cia yog qhov tseem ceeb. Peb tau pom cov haujlwm uas 321 fittings tau teeb tsa hauv 316L system thiab rov ua dua, pom tsuas yog thaum qib tsis raug ua tsis tiav ntxov.
Order khoom ntxiv rau 321 tej yaam num.Vim tias 321 tsis tshua muaj Tshuag, rov xaj ib qho me me nruab nrab ntawm - qhov project tuaj yeem txhais tau 6- lub lis piam tos. Order 5-10% ntxiv, tshwj xeeb tshaj yog rau qhov loj me lossis cov sijhawm teem sijhawm. Tus nqi nqa ntawm cov nyiaj seem 321 yog qis dua li qhov kev pheej hmoo ntawm kev ua haujlwm luv luv.
Xaus
Kev xaiv ntawm 316L thiab 321 tsis tshua nyuaj thaum koj tau txhais cov kev pabcuam kom meej. Qhov teeb meem yog tias ntau tus neeg yuav khoom mus txog qhov kev txiav txim siab yam tsis tas ua tus yam ntxwv ntawm ib puag ncig, ua txhaum cai rau qib lawv ib txwm siv. Uas ua hauj lwm kom txog thaum nws tsis.
Yog tias koj tab tom teev cov yeeb nkab rau ib txoj haujlwm tshiab, siv lub sijhawm los sau cov haujlwm kub, cov tshuaj chloride raug, acid concentration, thiab tsim lub neej. Plaub qhov kev ntsuas no yuav qhia koj qib twg koj xav tau kev ntseeg siab dua li cov lus sib piv. Thiab yog tias koj xav tau kev pab los ntawm qib twg, nrog rau tag nrho cov ntawv pov thawj zeb thiab kev xa khoom thoob ntiaj teb, peb nqa 316L thiab 321 hauv seamless thiab welded cov ntaub ntawv, nrog rau kev sib tw pob tw -weld fittings thiab flanges ib ASME B16.9, B16.11, thiab B16.5.
