Stainless hlau thiab Hastelloy steel tsum chaw tsim tshuaj paus,tiv tauj pebkom tau txais kev tsocai dawb thiab qauv!
Stainless hlau - Hlau-raws li, Chromium- txhais
Stainless hlauyog ib tsev neeg ntawm cov hlau -raws li (Fe) alloys txhais los ntawm qhov tsawg kawg nkaus chromium cov ntsiab lus ntawm10.5% los ntawm huab hwm coj(ISO 15510) Qhov chaw chromium no ua rau muaj qhov tsis pom, tus kheej - kho cov yeeb yaj kiab tsis zoo ntawm chromium oxide (Cr₂O₃) rau saum npoo - cov txheej txheem tom qab nws cov corrosion kuj. Yog tsis muaj zaj duab xis no, stainless hlau yuav corrode zoo li carbon hlau.
Cov qib siab tshaj plaws uas tau teev tseg hauv cov txheej txheem piping yog:304/304L(lub hom phiaj dav dav, 18% Cr / 8% Ni),316/316L(ntxiv 2-3% Mo rau kev txhim kho cov tshuaj chloride),317L(siab dua Mo, 3-4%), thiabwb 2205(22% Cr / 5% Ni / 3% Mo - siab zog thiab chloride kuj ua ke).
Hastelloy - Nickel-Raws li, Engineered for Aggression
Hastelloyyog lub npe lag luam sau npe rau ntau cov nickel{0}}raws li superalloys tsim los ntawm Haynes International. Tsis zoo li stainless hlau, lub hauv paus hlau yognickel (>50% yog '), tsis yog hlau. Qhov sib txawv tseem ceeb no muab rau Hastelloy qhov zoo sib txawv ntawm kev tiv thaiv corrosion - npib tsib xee matrix nws tus kheej yog cov resistant rau ob qho tib si oxidising thiab txo ib puag ncig, augmented los ntawm siab molybdenum (14-16%) thiab chromium ntxiv.
Cov qib feem ntau hauv cov txheej txheem chemical piping yogHastelloy C-276(UNS N10276) thiabHastelloy C-22(UNS N06022). Ob leeg raug cais raws li Corrosion Resistant Alloys (CRA) - lub sij hawm kev lag luam rau alloys xaiv tshwj xeeb rau huab cua corrosion ib puag ncig es tsis yog txhua yam kev ua haujlwm.
Chemical Composition: Dab tsi yog Hauv Txhua Alloy?
| Element | 316L Stainless hlau | TIAB SA 2205 | Hastelloy C-276 | Hastelloy C-22 | Muaj nuj nqi |
|---|---|---|---|---|---|
| Fe (Hlau) | Qhov nyiaj tshuav (~ 63%) | Qhov nyiaj tshuav (~ 69%) | 4–7% | 2–6% | Base hlau |
| Ni (Nickel) | 10–14% | 4.5–6.5% | Qhov nyiaj tshuav (~ 57%) | Qhov nyiaj tshuav (~ 56%) | Matrix corrosion kuj; austenite stability |
| Cr (Chromium) | 16–18% | 21–23% | 14.5–16.5% | 20–22.5% | Passive zaj duab xis tsim; oxidation tsis kam |
| Molybdenum (zeeg) | 2–3% | 3–3.5% | 15–17% | 12.5–14.5% | Pitting & crevice corrosion kuj; txo PREN qhov sib txawv |
| W (tungsten) | - | - | 3–4.5% | 2.5–3.5% | Txhim kho pitting tsis kam; localized corrosion kuj |
| Manganese (Mn) | Tsawg dua lossis sib npaug li 2% | Tsawg dua lossis sib npaug li 2% | Tsawg dua lossis sib npaug li 1% | Tsawg dua los yog sib npaug li 0.5% | Deoxidation |
| C (Carbon) | Tsawg dua lossis sib npaug li 0.03% (L qib) | Tsawg dua lossis sib npaug li 0.03% | Tsawg dua lossis sib npaug li 0.01% | Tsawg dua lossis sib npaug li 0.01% | Tsawg C tiv thaiv rhiab heev thaum vuam |
| Cobalt (zeeg) | - | - | Tsawg dua lossis sib npaug li 2.5% | Tsawg dua lossis sib npaug li 2.5% | Siab -temp stability |
Mechanical Properties Sib piv
| Khoom | 316L (ntxiv) | TIAB SA 2205 | Hastelloy C-276 (ntxiv) | Hastelloy C-22 (ntxiv) |
|---|---|---|---|---|
| Tensile zog (UTS) | 485-690 MPa | 620-900 MPa | 690-800 MPa | 690-795 MPa |
| Lub zog muaj zog (0.2%) | 170-310 MPa | 450-530 MPa | 280-350 MPa | 310-380 MPa |
| Elongation | 40% | 25% | 40–50% | 45–55% |
| Hardness | ~79 PAB | ~ 28 HRC max | ~ 90 PAB | ~ 100 PAB |
| Max Service Temp. | 870℃(oxidizing cua) | 300℃(limited) | 1,040 degree | 1,093 degree |
| Cryogenic Service | ✔ Zoo heev (FCC qauv) | Txwv tsis pub | ✔ Zoo heev (FCC qauv) | ✔ Zoo heev |
| Weldability | Zoo heev - tsis muaj PWHT | Zoo (ferrite tswj tseem ceeb) | Zoo - tsis xav tau PWHT | Zoo - tsis xav tau PWHT |
| Ua haujlwm -Hardening Rate | Siab | Nruab nrab | Siab | Siab |
| Machineability | Ncaj ncees (ua haujlwm- tawv) | Nyuaj | Nyuaj - yuav tsum muaj cov cuab yeej carbide | Nyuaj |
FAQ
Q: Dab tsi yog qhov txawv ntawm stainless hlau thiab Hastelloy?
Stainless steel is iron-based with ≥10.5% chromium, Hastelloy is nickel-based with >50% npib tsib xee. Qhov no ua rau Hastelloy tiv taus ntau dua los txo cov kua qaub thiab chlorides, tab sis tus nqi 6-10 × ntau dua 316L.
Q: Thaum twg kuv yuav tsum siv Hastelloy C-276 hloov 316L stainless hlau?
Use C-276 when: Cl⁻ >200 ppm ntawm elevated temp, HCl los yog H₂SO₄ tam sim no, ntub H₂S / qaub roj kev pab cuam, sib xyaw oxidising / txo cov xwm txheej (xws li, FGD), lossis 316L tau ua tsis tiav los ntawm pitting / SCC.
Q: Dab tsi yog PREN ntawm Hastelloy C-276 vs 316L stainless hlau?
316L: PREN ≈ 24. Hastelloy C-276: PREN ≈ 72. C-276's pitting resistance yog ze li ntawm 3 × siab dua, tseem ceeb heev rau cov cheeb tsam uas muaj cov tshuaj chloride.
Q: Puas yog Hastelloy muaj zog dua stainless hlau?
Thaum ambient temps, C-276 thiab 316L muaj zog zoo sib xws (~690 MPa UTS). Hastelloy qhov kom zoo dua yog siab -kev ua haujlwm kub - tuav lub zog rau 1,040℃vs 316L's 870℃. Duplex 2205 yeej muaj zog tawm los ntau dua li ob qho tib si.
Q: Cov qib sib txawv ntawm Hastelloy yog dab tsi?
C-276- feem ntau, tag nrho - nyob ib ncig ntawm corrosion kuj,C-22- zoo dua hauv oxidising acids (HNO₃),B-3- HCl tus kws tshaj lij, tsis yog rau oxidizing media,X- siab -temp gas turbines.
Q: Puas yog Hastelloy xeb?
No. Its >50% npib tsib xee puag tiv thaiv corrosion yam tsis muaj kev cia siab ib leeg rau ib zaj duab xis passive. Kev tiv thaiv kab mob chloride SCC thiab HIC. Tsuas yog yooj yim rau cov kub concentrated oxidising acids (xws li, HNO₃ + HF), qhov twg C-22 ua tau zoo dua.
Q: Puas tuaj yeem stainless hlau hloov Hastelloy kom txuag tau nqi?
Yes - 316L handles most general service. Upgrade to Hastelloy only when corrosion data shows >0.1 hli / xyoo nres ntawm stainless. Super duplex 2507 (PREN 43) yog tus nqi -kev xaiv nruab nrab zoo.
Q: Dab tsi cov qauv npog Hastelloy yeeb nkab khoom?
ASTM B622 / SB-622 (seamless), ASTM B619 / SB-619 (welded yeeb nkab), ASTM B626 / SB-626 (kub exchanger raj). Dimensions rau ASME B36.19 / B36.10. Qhia UNS tus lej (N10276 rau C-276, N06022 rau C-22).
