439 vs 441 Stainless hlau: Advanced Ferritics rau Exhaust Systems

 

Dab tsi yog cov tshuaj muaj pes tsawg leeg, cov yam ntxwv tseem ceeb, thiab kev siv ntawm 439 thiab 441 stainless hlau?
Ob leeg yog ib feem ntawm cov tiam tshiab ntawm ferritic exhaust steels. Qib 439 (UNS S43900) muaj txog 17-19% Cr thiab ruaj khov nrog titanium. Qib 441 (feem ntau UNS S44100) muaj qhov zoo sib xws tab sis feem ntau suav nrog me me ntxiv ntawm niobium (~ 0.3-0.6%) thiab tej zaum yuav muaj cov ntsiab lus chromium siab dua me ntsis. Lub niobium muab kev ruaj khov ntxiv thiab txhim kho qhov kub thiab txias. Lawv cov yam ntxwv tseem ceeb yog kev ua haujlwm zoo heev rau cov pa roj carbon monoxide, zoo thermal qaug zog zog, thiab zoo weldability. Lawv yog siv rau tag nrho cov pa system, los ntawm manifolds thiab catalytic converter plhaub rau mufflers thiab tailpipes, hloov cov qib qub xws li 409.

Micro-Alloying nrog niobium hauv 441 li cas los txhim kho nws cov kev ua tau zoo hauv cov ntawv siv kub- kawg?
Niobium tsim cov carbides ruaj khov thiab nitrides. Nyob rau hauv 441, qhov no muab kev tiv thaiv superior rau siab - kub "sagging" los yog deformation nyob rau hauv load piv rau 439. Qhov no yog ib qho tseem ceeb heev rau cov pa manifolds thiab downpipes uas muaj huab cua kub. Lub niobium kuj tseem ua kom zoo dua cov qauv nplej, txhim kho toughness thiab qaug zog tiv thaiv thaum lub sij hawm thermal voj voog ntawm lub tso pa tawm. Rau cov chaw tsim khoom tsim lub teeb yuag, nyias- cov khoom siv phab ntsa uas yuav tsum tiv taus qhov kub siab dua los ntawm cov tshuab niaj hnub no, 441 muaj cov txiaj ntsig tseem ceeb.

Puas muaj qhov sib txawv tseem ceeb hauv kev tsim khoom lossis tus nqi ntawm 439 thiab 441?
Ob qib yog tsim los rau zoo formability thiab weldability nyob rau hauv siab - ceev automotive ntau lawm kab. Vuam ob qho tib si yog ncaj nraim nrog cov txheej txheem txheej txheem. Tus nqi sib txawv feem ntau yog tsawg, vim qhov sib ntxiv ntawm niobium hauv 441 yog me me. Qhov kev xaiv feem ntau yog tsav los ntawm kev tshwj xeeb OEM engineering specifications thiab cov kev ua tau zoo ntawm cov khoom tshwj xeeb qhov chaw nyob hauv qhov tso pa tawm. Qee cov tuam txhab tsim qauv ntawm 441 rau nws lub hnab ntawv ua haujlwm me ntsis thoob plaws ob qhov kub thiab txias kawg.

Dab tsi yog qhov kev lag luam tam sim no hais txog kev siv cov qib no hauv kev tsim tsheb?
Cov qauv no muaj zog rau cov qib ferritic ruaj khov (439, 441, thiab zoo sib xws) rau tag nrho cov tshuab pa. Lawv tab tom hloov 409 nyob rau hauv txias kawg thiab tau nce ntxiv rau qhov kub kawg uas 409 tsis txaus. Qhov kev hloov pauv no yog tsav los ntawm lub sijhawm lav ntev dua, lub cav kub siab dua, thiab kev xav tau sib dua - lub cev hnyav. Siv ib leeg, qib weldable zoo li 441 rau tag nrho cov kab ke ua haujlwm yooj yim rau kev tsim khoom thiab cov khoom muag, thaum muab cov kav ntev uas yuav tsum tau ua kom tau raws li qhov kev siv hluav taws xob nruj nruj.

Yuav ua li cas tus engineer lossis tus neeg yuav khoom txiav txim siab ntawm kev qhia 439 lossis 441 rau ib feem?
Qhov kev txiav txim siab yuav tsum yog nyob ntawm qhov ntsuas qhov siab tshaj plaws ntawm kev ua haujlwm thiab cov khoom siv thauj khoom nws dais. Rau cov khoom kub tshaj plaws (manifolds, downpipes) lossis rau cov qauv tsim thawb cov kev txwv ntawm nyias- phab ntsa kev tsim kho, qhia 441 rau nws qhov siab dua - qhov kub thiab txias. Rau cov txheej txheem txias- kawg cov khoom (mufflers, tailpipes) lossis tus nqi- cov ntawv siv tau yooj yim uas qhov kev ua haujlwm kub siab tshaj plaws tsis tseem ceeb, 439 muab kev pabcuam zoo heev. Kev sab laj cov ntaub ntawv cov ntaub ntawv los ntawm cov mills muaj npe nrov thiab tshuaj xyuas cov neeg sib tw benchmarking yog cov kauj ruam tseem ceeb hauv kev xaiv.