304 vs 304L Stainless Hlau: Qhov sib txawv thiab kev siv

2025-04-16 IB

Qib 304 thiab 304L stainless steels qeb ntawm cov khoom siv nrov tshaj plaws austenitic, khoom plig rau lawv cov kev tiv thaiv corrosion zoo thiab yoog raws. Kev xaiv qhov yog txhais tau tias nkag siab hloov maj mam-tab sis tseem ceeb-qhov sib txawv hauv chemistry thiab kev ua tau zoo. Phau ntawv qhia no ua raws li cov qauv uas paub zoo-kev sib xyaw, cov khoom, weldability, kev siv, thiab tus nqi-thaum muab cov kev xav tshiab los pab koj xaiv qhov kev paub. 304vs304l ua

Chemical Composition ntawm 304 thiab 304L Stainless hlau

304 Stainless hlau
- Cov pa roj carbon (C): 0.08%
- Chromium (Cr): 18-20%
- Nickel (Ni): 8-10.5%
304L Stainless hlau
- Cov pa roj carbon (C): 0.03%
- Chromium (Cr): 18-20%
- Nickel (Ni): 8-12%

Qhov sib txawv ntawm qhov sib txawv yog cov ntsiab lus carbon. Nrog nws cov trimmed-down carbon, 304L tiv thaiv kev tsim ntawm chromium carbides ntawm grain ciam teb thaum vuam, khaws cia nws tsis kam mus rau intergranular corrosion. (Xav txog 304 raws li tus kws tsim lub cev-bulking ntawm cov pa roj carbon-thaum 304L yog tus kws qhia yoga, lean thiab hloov pauv hauv thaj chaw muaj kev kub ntxhov.)

Kev sib piv ntawm lub cev thiab cov cuab yeej cuab tam

Khoom	304	304l ua	Nws txhais li cas
Tensile zog (MPa)	520–750	485–690	304 rub marginally nyuaj, tab sis ob qho tib si ntau tshaj qhov xav tau
Yield zog (MPa)	205–215	~ 170–200	Ntug me me rau 304 rau kev siv cov khoom siv thauj khoom
Elongation (%)	≥ 40	≥ 40	Zoo stretchability nyob rau hauv ob qho tib si rau complex txoj kev
Hardness (Brinell)	~ 70–90	~ 65–85	Yuav luag zoo ib yam hauv kev siv
Corrosion Resistance	Zoo heev (zoo ib puag ncig)	Superior nyob rau hauv welded seem	304L ci tom qab vuam yam tsis muaj kev kho cua sov ntxiv

Weldability thiab Fabrication

Weldability
Ob qho tib si alloys tau yooj yim welded nrog cov txheej txheem pa. Txawm li cas los xij, 304L cov pa roj carbon tsawg txhais tau tias koj tuaj yeem hla tom qab vuam annealing - txuag lub sijhawm thiab lub zog.

Machineability
Austenitic stainless hlau zoo li ua haujlwm hnyav. Txhawm rau tiv thaiv kev sib tsoo thiab cov cuab yeej ua ntej hnav, siv cov npoo ntse ntse, tus nqi noj nruab nrab, thiab lubrication txaus. Lub me ntsis softer 304L yuav muab ib tug smoother tiav nyob rau hauv zoo tib yam mob.

Kev siv ntawm 304 thiab 304L Stainless Steels

304 Stainless hlau

Kev lag luam hauv chav ua noj dab dej, cookware, thiab khoom noj khoom haus
Kho kom zoo nkauj architectural nta (piv txwv li, railings, cladding)
Cia cov hlab ntsha thiab nruab nrab kub siab tanks

304L Stainless hlau

Chemical processing thiab petrochemical piping (nrog weld seams)
Thaum tshav kub kub exchangers thiab condensers (tseem ceeb weld kev ncaj ncees)
Pharmaceutical thiab mis nyuj kev lag luam tso tsheb hlau luam (ntau zaus weld refurbishments)

Nqi thiab Muaj

Nqi
Cia siab tias 304L yuav nqa tus nqi qis-feem ntau 3-7% siab dua-xav txog nws cov txiaj ntsig qis-carbon hauv cov khoom sib dhos. Ntawm kev txiav txim loj, qhov sib txawv tuaj yeem ntxiv, yog li muab nws tso rau hauv koj cov peev nyiaj.

Muaj
Ob qib yog staples nyob rau hauv cov khoom siv hlau: nplooj ntawv, daim hlau, tuav, tubing, thiab lwm yam nyob rau hauv ntau qhov ntev. Lub sij hawm ua tus qauv luv luv, tab sis rau cov ntawv tshwj xeeb lossis cov ntu tuab, npaj ua ntej.

Xaus

Qib 304 thiab 304L sib koom ua ke ntawm cov pob txha zoo ntawm corrosion kuj thiab formability. Koj qhov kev txiav txim siab hinges ntawm vuam xav tau thiab cov kev pab cuam: xaiv 304L thaum txo qis tom qab vuam kev kho cua sov thiab ua kom qhov vuam-zone corrosion kuj tseem ceeb; xaiv rau 304 yog tias koj xav tau me ntsis ntxiv lub zog rau cov khoom siv dav dav. Nrog rau kev hloov pauv kev koom nrog thev naus laus zis thiab kev txhawb nqa kev ruaj ntseg, ob qho tib si alloys yuav nyob twj ywm ua haujlwm thoob plaws kev lag luam rau xyoo tom ntej.