409 Stainless Hlau (UNS S40900): Qhov tseem ceeb Automotive Exhaust Alloy

 

Dab tsi yog qhov yooj yim muaj pes tsawg leeg, cov yam ntxwv tseem ceeb, thiab kev lag luam tseem ceeb ntawm 409 stainless hlau?
Cov hlau no yog ferritic stainless hlau nrog cov ntsiab lus chromium tsawg (10.5-11.75%), ruaj khov nrog titanium (feem ntau yog 6 npaug ntawm cov ntsiab lus carbon). Nws qib qis chromium ua rau nws raug nqi, thaum titanium stabilization muab kev tiv thaiv rau intergranular corrosion. Nws cov yam ntxwv tseem ceeb yog kev tiv thaiv zoo heev rau oxidation thiab corrosion los ntawm automotive pa gases thiab condensates. Nws txoj kev siv tseem ceeb yog nyob rau hauv kev lag luam tsheb rau cov khoom siv hluav taws xob, los ntawm qhov kub kawg mus rau tailpipe. Nws kuj muaj nyob rau hauv cov khoom siv ua liaj ua teb, cov khoom siv hluav taws xob, thiab cov khoom siv hluav taws xob.

Vim li cas 409 thiaj li zoo- haum rau cov tsheb siv hluav taws xob siv piv rau lwm cov qib stainless?
409 yog engineered rau lub luag hauj lwm no. Nws tiv taus oxidation ntawm qhov kub thiab txias tau ntsib hauv cov tshuab pa (txog ~ 700℃intermittently). Lub titanium stabilization tiv thaiv "weld decay," tso cai rau cov khoom yuav tsum tau welded thaum lub sij hawm sib dhos yam tsis muaj qhov tsis zoo ntawm corrosion kuj ntawm lub vuam. Nws cov qauv ferritic muab cov thermal qaug zog zoo rau cov cua sov / cua txias ntawm lub tsheb. Qhov tseem ceeb, nws muab qhov kev ua tau zoo ntawm tus nqi qis dua npib tsib xee- muaj cov qib austenitic zoo li 304, uas yog qhov tseem ceeb rau siab - ntim pib tsim.

Nws qhov kev ua tau zoo thiab kev siv sib txawv li cas ntawm qhov kub kawg thiab qhov txias kawg ntawm qhov tso pa tawm?
Nyob rau hauv qhov kub kub nyob ze ntawm lub cav (manifold, downpipe), qhov kub siab tshaj plaws, 409 tej zaum yuav siv tau tab sis qee zaum hloov mus rau siab dua -qib ferritics xws li 439 lossis 441 kom zoo dua oxidation tsis kam. Nws daim ntawv thov feem ntau thiab zoo tshaj plaws yog nyob rau hauv "txias kawg": mufflers, resonators, tailpipes, thiab catalytic converter vaj tsev. Ntawm no, qhov kub thiab txias yog qis dua, thiab nws tsis kam tiv thaiv corrosion los ntawm acidic condensates (tsim thaum lub tso cua txias) yog cov cuab yeej tseem ceeb. Nws tus nqi qis ua rau nws zoo meej rau cov khoom loj, pom tau.

Yuav ua li cas manufacturers yuav tsum paub txog vuam thiab fabricating 409 stainless hlau?
409 yog suav tias yog nkag tau yooj yim weldable siv ntau txoj kev xws li GTAW (TIG) thiab GMAW (MIG). Nws cov titanium-stabilized chemistry yog zam txim thiab pab tswj corrosion kuj nyob rau hauv weld cheeb tsam. Txheem ER409 lossis ER409Cb muab cov hlau siv. Txhawm rau kom tau txais txiaj ntsig zoo tshaj plaws, kev ntxuav kom raug thiab tiv thaiv roj tau raug pom zoo. Nws muaj zoo formability rau dov thiab dabtsi yog khoov rau hauv cov yeeb nkab complex. Cov neeg tsim khoom txaus siab rau nws qhov sib xws thiab kev ntseeg siab hauv siab - qhov chaw tsim khoom ceev.

Dab tsi yog qhov tseem ceeb rau kev siv txuas ntxiv thiab yav tom ntej ntawm 409 hauv kev tsim tsheb?
Cov tsav tsheb tseem ceeb yog tus nqi, kev ua raws cai, thiab kev hloov pauv ntawm cov khoom siv. Automakers ntsib tus nqi siab, thiab 409 tseem yog cov kev siv nyiaj tsis zoo tshaj plaws uas ua tau raws li kev ua neej nyob thiab kev tiv thaiv emissions. Cov kev cai ib puag ncig thawb kom ntev ntev ntawm cov khoom siv hluav taws xob txuas ntxiv mus rau kev tswj hwm stainless hla aluminized steel. Tsis tas li ntawd, kev txhim kho tsis tu ncua tau ua rau txhim kho cov qauv ntawm 409 nrog kev txhim kho siab - qhov kub thiab txias, ua kom nws muaj feem cuam tshuam rau tom ntej - tiam tso tawm rau ob qho tib si combustion thiab hybrid tsheb.