904L yog ib qho uas tsis muaj kev ruaj ntseg qis carbon siab alloy austenitic stainless hlau.Qhov sib ntxiv ntawm tooj liab rau qib no ua rau nws zoo heev tiv thaiv kom muaj zog txo cov acids, tshwj xeeb tshaj yog sulfuric acid.Nws kuj tseem tiv taus chloride nres - ob qho tib si pitting / crevice corrosion thiab kev ntxhov siab corrosion tawg.
Qib no tsis yog-sib nqus nyob rau hauv tag nrho cov mob thiab muaj zoo weldability thiab formability.Cov qauv austenitic kuj muab cov qib no zoo heev toughness, txawm mus rau cryogenic kub.
904L muaj cov ntsiab lus tseem ceeb ntawm cov khoom xyaw nqi siab nickel thiab molybdenum.Ntau daim ntawv thov uas qib no yav dhau los ua tau zoo tam sim no tuaj yeem ua tiav ntawm tus nqi qis dua los ntawm duplex stainless hlau 2205 (S31803 lossis S32205), yog li nws siv tsawg dua yav dhau los.
Cov khoom tseem ceeb
Cov khoom no tau teev tseg rau cov khoom lag luam tiaj tus (phaj, ntawv thiab coil) hauv ASTM B625.Zoo sib xws tab sis tsis tas yuav zoo ib yam khoom yog teev rau lwm yam khoom xws li yeeb nkab, raj thiab bar hauv lawv cov specifications.
Kev sib xyaw
Table 1.Kev sib xyaw ua ke rau 904L qib ntawm stainless hlau.
| Qib | C | Mn | Si | P | S | Cr | Mo | Ni | Cu | |
| 904l ua | min. max. | - 0.020 ib | - 2.00 Nws | - 1.00 Nws | - 0.045 ib | - 0.035 ib | 19.0 Nws 23.0 Nws | 4.0 5.0 | 23.0 Nws 28.0 Nws | 1.0 2.0 |
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Mechanical Properties
Rooj 2.Mechanical zog ntawm 904L qib stainless hlau.
| Qib | Tensile zog (MPa) min | Yield zog 0.2% Pov thawj (MPa) min | Elongation (% hauv 50mm) min | Hardness | |
| Rockwell B (HWV B) | Brinell (HB) | ||||
| 904l ua | 490 ib | 220 | 35 | 70-90 UAS | - |
| Rockwell Hardness tus nqi ntau yog raug nkaus xwb;lwm yam nuj nqis yog teev txwv. | |||||
Lub cev muaj zog
Table 3.Cov khoom siv lub cev zoo rau 904L qib stainless hlau.
| Qib | Qhov ntom | Elastic Modulus | Qhov nruab nrab Co-eff ntawm Thermal Expansion (µm/m/°C) | Thermal conductivity | Kev kub ceev 0-100 ° C | Elec Resistivity | |||
| 0-100 ° C | 0-315 ° C | 0-538 ° C | Ntawm 20 ° C | Ntawm 500 ° C | |||||
| 904l ua | 8000 | 200 | 15 | - | - | 13 | - | 500 | 850 |
Qib Specification piv
Table 4.Qib specifications rau 904L qib stainless hlau.
| Qib | UNS No | Laus British | Euronorm | Swedish SS | Japanese JIS | ||
| BS | En | No | Lub npe | ||||
| 904l ua | n08904 ua | 9 04s13 | - | 1.4539 ib | X1NiCrMoCuN25-20-5 | 2562 ib | - |
| Cov kev sib piv no tsuas yog kwv yees xwb.Daim ntawv teev npe yog npaj raws li kev sib piv ntawm cov khoom siv zoo sib xwstsis yograws li lub sij hawm ntawm kev sib cog lus sib npaug.Yog tias qhov sib npaug tiag tiag xav tau thawj cov ntsiab lus yuav tsum tau sab laj. | |||||||
Cov qhab nia xaiv tau
Table 5.Muaj peev xwm hloov qib rau 904L stainless hlau.
| Qib | Vim li cas nws thiaj yuav raug xaiv los ntawm 904L |
| 316l ua | Lwm tus nqi qis dua, tab sis nrog qis dua corrosion kuj. |
| 6 ib mo | Yuav tsum muaj kev tiv thaiv ntau dua rau pitting thiab crevice corrosion kuj. |
| 2205 | Ib qho zoo sib xws corrosion kuj, nrog rau 2205 muaj zog dua txhua yam, thiab ntawm tus nqi qis rau 904L.(2205 tsis haum rau qhov kub siab tshaj 300 ° C.) |
| Super duplex | Yuav tsum muaj kev tiv thaiv corrosion siab dua, ua ke nrog lub zog siab dua 904L. |
Corrosion Resistance
Txawm hais tias Ameslikas tsim rau nws cov tsis kam mus rau sulfuric acid nws kuj muaj kev tiv thaiv siab heev rau ntau qhov chaw ib puag ncig.PRE ntawm 35 qhia tias cov khoom muaj kev tiv thaiv zoo rau cov dej hiav txwv sov thiab lwm qhov chaw muaj chloride siab.Cov ntsiab lus siab nickel ua rau muaj kev tiv thaiv zoo dua rau kev ntxhov siab corrosion tawg dua li cov qib austenitic tus qauv.Tooj liab ntxiv tsis kam mus rau sulfuric thiab lwm yam kev txo cov kua qaub, tshwj xeeb tshaj yog nyob rau hauv qhov hnyav heev "mid concentration" ntau yam.
Nyob rau hauv feem ntau ib puag ncig 904L muaj kev ua haujlwm corrosion nruab nrab ntawm tus qauv austenitic qib 316L thiab cov alloyed 6% molybdenum thiab zoo sib xws "super austenitic" qib.
Hauv kev txhoj puab heev nitric acid 904L muaj kev tiv thaiv tsawg dua li molybdenum-dawb qib xws li 304L thiab 310L.
Rau siab tshaj plaws kev ntxhov siab corrosion cracking kuj nyob rau hauv ib qho tseem ceeb ib puag ncig cov hlau yuav tsum tau kho tom qab txias ua hauj lwm.
Thaum tshav kub kub Resistance
Kev tiv thaiv zoo rau oxidation, tab sis zoo li lwm cov qib alloyed heev raug kev txom nyem los ntawm cov txheej txheem tsis ruaj khov ( nag lossis daus ntawm nkig theem xws li sigma ) ntawm qhov kub siab.904L yuav tsum tsis txhob siv siab tshaj li 400 ° C.
Kev kho cua sov
Kev Kho Hniav (Annealing) - kub rau 1090-1175 ° C thiab txias sai.Qib no tsis tuaj yeem hardened los ntawm kev kho cua sov.
Vuam
904L tuaj yeem ua tiav welded los ntawm txhua txoj hauv kev.Kev saib xyuas yuav tsum tau ua raws li qib no solidifies tag nrho austenitic, yog li cuam tshuam rau kub tawg, tshwj xeeb tshaj yog nyob rau hauv constrained weldments.Tsis siv cov cua sov ua ntej yuav tsum tau siv thiab feem ntau tom qab kev kho cua sov kuj tsis tas yuav tsum tau ua.AS 1554.6 ua ntej tsim nyog Qib 904L rods thiab electrodes rau vuam ntawm 904L.
Fabrication
904L yog purity siab, tsis tshua muaj sulfur qib, thiab xws li yuav tsis tshuab zoo.Txawm li cas los xij, qib no tuaj yeem raug machined siv cov txheej txheem txheej txheem.
Khoov mus rau ib lub vojvoog me me yog npaj txhij.Feem ntau qhov no yog ua kom txias.Tom qab annealing feem ntau tsis tas yuav tsum tau, txawm hais tias nws yuav tsum tau txiav txim siab yog tias fabrication yuav tsum tau siv nyob rau hauv ib puag ncig uas muaj kev nyuaj siab corrosion cracking mob hnyav.
Daim ntawv thov
Cov ntawv thov ib txwm muaj xws li:
• Kev cog qoob loo rau sulfuric, phosphoric thiab acetic acids
• Pulp thiab ntawv ua
• Cheebtsam hauv cov pa roj txhuam cov nroj tsuag
• Cov khoom siv cua txias dej hiav txwv
• Roj refinery Cheebtsam
• Hlau nyob rau hauv electrostatic precipitators