Alloy C-276 nickel alloy Corrosion Resistance
Alloy C-276 npib tsib xee alloy phaj yog ib qho ntawm cov khoom siv tiv thaiv corrosion zoo tshaj plaws uas ua tau zoo heev hauv ob qho tib si oxidizing thiab txo qhov chaw. Nws tiv taus chloride kev nyuaj siab corrosion cracking, pitting, crevice thiab dav corrosion. Cov hlau kuj tseem tiv taus carbide nag lossis daus thaum lub sijhawm vuam ua kom nws siv tau rau hauv qhov xwm txheej zoo li-welded.
Hauv kev siv tshuaj lom neeg, cov hlau muaj qhov tshwj xeeb tiv thaiv sulfuric, hydrochloric, formic, acetic thiab phosphoric acids. Alloy C-276 npib tsib xee alloy phaj ua tau zoo nyob rau hauv ib puag ncig uas muaj cov kua qaub chlorides, cov kuab tshuaj thiab acetic anhydride, Cov hlau yog ib qho ntawm ob peb qib uas tiv taus cov roj chlorine ntub dej, cov tshuaj hypochlorite thiab chlorine dioxide.
Alloy C-276 npib tsib xee alloy phaj yog tiv taus siab rau cov ntsiab lus ntawm oxidizing ntsev xws li hlau thiab tooj liab chloride. Nws kuj ua tau zoo nyob rau hauv dej hiav txwv, tshwj xeeb tshaj yog nyob rau hauv crevice tej yam kev mob uas lwm yam nquag siv alloys xws li stainless hlau, Alloy 400 thiab Alloy 625 tsis.
Cov kev ua haujlwm ntawm flue gas desulfurization systems muaj qhov nyuaj rau cov khoom siv tiv thaiv corrosion. Scrubber cawv thiab roj condensates feem ntau muaj chlorides. Alloy C-276 npib tsib xee alloy phaj npib tsib xee alloy phaj tau pom tias tiv taus cov tshuaj chloride ntau dua li lwm qib ua ntej qhov pib ntawm qhov chaw xeb hauv cov tshuab no.
Alloy C-276 npib tsib xee alloy phaj yog siv dav hauv kev rov qab los thiab ua cov roj ntsha qaub uas muaj hydrogen sulfide nrog rau carbon dioxide thiab chlorides. Cov pa roj carbon thiab alloy steels tsis tuaj yeem tiv taus qhov chaw corrosive. Lawv raug ua tsis tiav los ntawm sulfide kev ntxhov siab tawg lossis kev ntxhov siab corrosion tawg. Cov nplua nuj chemistry ntawm Alloy C-276 npib tsib xee alloy phaj ua rau nws resistant rau qaub ib puag ncig txawm nyob rau hauv kub kub nyob rau hauv qhov tob tob.
Corrosion Tests * hauv Hydrogen Fluoride Gas.
Test Duration, 36 Teev. Kub 932-1112 degree F (500-600 degree)
| KHOOM | Corrosion tus nqi, mpy (mm/a) | Cov lus pom |
|---|---|---|
| Alloy C-276 | 0.3 (0.01) | Iridescent tarnish zaj duab xis |
| Alloy 600 | 0.7 (0.02) | Iridescent tarnish zaj duab xis |
| Nickel 200 | 9 (0.23) | Zaj duab xis dub |
| Nickel 201 | 14 (0.36) | Zaj duab xis dub |
| Alloy 400 | 13 (0.33) | Adherent tsaus zaj duab xis |
| Alloy K-500 | 16 (0.41) | Adherent tsaus zaj duab xis |
| 70/30 Tooj-Nickel | 16 (0.41) | Adherent tsaus zaj duab xis |
* 7 lb HF ib teev twg ntawm 4 psig tau dhau los ntawm chav kuaj qhov cub rau hydroflourination ntawm hlau oxides
Corrosion-resistance ntawm npib tsib xee alloys nyob rau hauv plaub 24- teev kev ntsuam xyuas hauv boiling acetic acid
| Alloy | Ni | Cr | Mo | W | Nb | N | PREN |
|---|---|---|---|---|---|---|---|
| 316 Stainless hlau | 12 | 17 | 2.2 | — | — | — | 20.4 |
| 317 Stainless hlau | 13 | 18 | 3.8 | — | — | — | 23.7 |
| alloy 825 | 42 | 21.5 | 3 | — | — | — | 26.0 |
| Alloy G-3 | 44 | 22 | 7 | — | — | — | 32.5 |
| Alloy 25-6MO | 25 | 20 | 6.5 | — | — | 0.20 | 35.8 |
| alloy 625 | 62 | 22 | 9 | — | 3.5 | — | 40.8 |
| Alloy C-276 | 58 | 16 | 16 | 3.5 | — | — | 45.2 |
| alloy 622 | 60 | 20.5 | 14 | 3.5 | — | — | 46.8 |
| alloy 686 | 58 | 20.5 | 16.3 | 3.5 | — | — | 50.8 |
* (Pren)=feem pua CR ntxiv rau 1.5 (feem pua Mo plus feem pua W ntxiv rau feem pua Nb) ntxiv rau 30 (feem pua N)
Maximum Pitting lossis Crevice Attack, mils (MM), hauv FGD Scrubber Slurrya
| Alloy | Quencher | Absorber | Absorber Qhov hluav taws xob |
Qhov hluav taws xob Cov kav dej |
Bypass Cov kav dej |
|---|---|---|---|---|---|
| 316L Stainless hlau | 22 (0.56) | 21 (0.53) | 35 (0.89)b | 35 (0.89)b | 12 (0.30) |
| 317LM Stainless hlau | 20 (0.51) | 22 (0.56) | 29 (0.74) | 33 (0.84) | 29 (0.74) |
| alloy 825 | 15 (0.38) | 33 (0.84) | 39 (0.99) | 50 (1.27)b | 10 (0.25) |
| alloy 625 | <2 (<0.05) | 10 (0.25) | 11 (0.28) | 7 (0.18) | tsis muaj |
| Alloy C-276 | tsis muaj | tsis muaj | <2 (<0.05) | tsis muaj | tsis muaj |
a6-hli raug ntawm 126 degree F (62 degree), pH 5.5, 5000 ppm chlorides
bPerforated.
