Cov khoom sib txawv thiab cov xwm txheej siv tau ntawm National Standard thiab Foreign Standard Rails
Dab tsi yog cov khoom tseem ceeb ntawm lub teb chaws tus qauv rails?
Cov ntaub ntawv tseem ceeb ntawm lub teb chaws tus qauv yog U71Mn thiab U75V. U71Mn muaj cov ntsiab lus carbon ntawm 0.65%{19}}0.76% thiab manganese cov ntsiab lus ntawm 1.10%{20}}1.50%, nrog lub zog zoo thiab tawv. U75V muaj cov ntsiab lus carbon ntawm 0.70%-0.80% thiab muaj 0.04%-0.12% vanadium, nws qhov kev ua tau zoo yog txhim kho los ntawm microalloying technology. Cov ntsiab lus phosphorus thiab sulfur ntawm ob cov ntaub ntawv raug tswj tsawg dua lossis sib npaug li 0.030% kom ntseeg tau tias kev ua haujlwm ruaj khov. U71Mn tau siv dav hauv kev tsheb ciav hlau zoo tib yam, thaum U75V yog qhov tsim nyog rau kev tsheb ciav hlau hnyav thiab qee qhov kev tsheb ciav hlau ceev. Lawv cov khoom xaiv nruj me ntsis phim cov kev xav tau ntawm cov kab sib txawv kom ntseeg tau tias kev ruaj ntseg ntawm lub hauv paus khiav.
Dab tsi yog cov yam ntxwv ntawm cov khoom siv rau txawv teb chaws tus qauv rails?
European standard UIC rails feem ntau siv S355Jr cov khoom, nrog lub zog tawm los ntawm ntau dua lossis sib npaug ntawm 355MPa thiab cov ntsiab lus carbon tsawg dua lossis sib npaug li 0.22%, uas nws qhov txiaj ntsig zoo tshaj plaws yog weldability zoo heev, haum rau Europe txoj kev tsheb ciav hlau ntom ntom. Asmeskas tus qauv AREMA rails txais cov khoom siv xws li AAR M102 Qib 115, nrog lub zog tensile ntawm Ntau dua lossis sib npaug rau 790MPa, tsom rau kev txhim kho kev qaug zog. Lavxias tus qauv GOST R 51685 rails ntxiv cov ntsiab lus hlau xws li chromium thiab npib tsib xee, nrog rau qhov tsis tshua muaj siab -kub toughness. Cov ntaub ntawv no txhua tus ua kom zoo tshaj qhov sib piv ntawm cov alloy kom hloov mus rau txoj kev tsheb ciav hlau ua haujlwm nyob rau hauv lawv cheeb tsam. Cov qauv tsim ntawm cov khoom siv txawv teb chaws yog ua kom haum rau cov kev xav tau tiag tiag xws li lub nra hnyav thiab kev nyab xeeb ntawm cov kab hauv zos.
Cov khoom sib txawv li cas cuam tshuam rau kev ua tau zoo ntawm cov ntsia hlau?
Lub zog tensile ntawm lub teb chaws tus qauv U75V rails tuaj yeem ncav cuag tshaj 980MPa, deb tshaj 510-680MPa ntawm European S355Jr, uas tuaj yeem tiv taus lub log zoo dua -rail siab thaum hnyav- tsheb thauj mus los. Nyob rau hauv lub sij hawm ntev - lub sij hawm cyclic loading, lub neej qaug zog ntawm American AAR M102 Qib 115 rails yog 20%-30% siab dua li lub teb chaws tus qauv U71Mn. Alloy ntsiab nyob rau hauv cov khoom yog tus yuam sij rau lub zog sib txawv; cov ntsiab lus xws li vanadium thiab chromium tuaj yeem txhim kho hardness thiab hnav tsis kam ntawm hlau. Hnyav- cov kab tsheb yuav tsum xaiv cov ntaub ntawv muaj zog kom txo qis deformation, thaum cov kab zoo tib yam tuaj yeem sib npaug zog thiab tus nqi. Cov khoom siv lub zog ncaj qha txiav txim siab qhov kev txwv ntawm kev thauj khoom thiab kev pabcuam lub neej ntawm cov ntsia hlau, uas yog qhov tseem ceeb ntawm kev tsim kab.
Dab tsi yog qhov sib txawv ntawm cov txheej txheem vuam rau cov khoom sib txawv?
Lub teb chaws tus qauv U71Mn rails feem ntau siv lub taub qab vuam, nrog rau qhov kub thiab txias tswj ntawm 800-900℃thiab qhov kev ntxhov siab ntawm 100-120MPa los xyuas kom meej tias lub zog ntawm cov welded sib koom ua ke zoo ib yam nrog lub hauv paus hlau. Vim nws cov weldability zoo, European S355Jr tuaj yeem siv cov roj siv yooj yim dua vuam, nrog rau qhov kub thiab txias ntawm 1200-1300℃thiab ua haujlwm ntau dua. American AAR M102 Qib 115 yuav tsum tau siv cov electrodes tshwj xeeb uas muaj npib tsib xee thiab molybdenum los xyuas kom meej qhov toughness thiab lub zog sib txuam ntawm kev sib koom ua ke. Kev xaiv cov txheej txheem vuam yuav tsum hloov mus rau cov tshuaj muaj pes tsawg leeg ntawm cov khoom kom tsis txhob muaj qhov tsis xws luag. Lub hom phiaj tseem ceeb ntawm cov txheej txheem vuam sib txawv yog txhawm rau tshem tawm cov teeb meem sib koom ua ke los ntawm cov khoom sib txawv thiab xyuas kom muaj kev ncaj ncees.
Yuav ua li cas xaiv cov khoom hloov mus rau qhov chaw ua haujlwm sib txawv?
Rau kev tsheb ciav hlau nyob rau hauv siab - qhov kub thiab txias ntawm thaj chaw suab puam, lub teb chaws tus qauv cua sov- cov kab hluav taws xob uas muaj chromium thiab molybdenum feem ntau raug xaiv los tiv thaiv deformation los ntawm thermal expansion thiab contraction. Hauv cov cheeb tsam txias, cov txheej txheem txawv teb chaws uas muaj cov npib tsib xee yog qhov nyiam kom tsis txhob muaj qhov kub tsawg - qhov kub thiab txias tawg. Hnyav- kev tsheb ciav hlau yuav tsum muaj siab -lub zog thiab hnav- cov ntaub ntawv tiv taus, xws li lub teb chaws tus qauv U75V thiab American AAR M102 Qib 115. Cov kev tsheb ciav hlau nruab nrab tuaj yeem xaiv U71Mn cov khoom siv nrog cov nqi siab dua kom sib npaug ntawm kev ua haujlwm thiab tus nqi. Kev xaiv cov khoom siv yuav tsum ua tib zoo xav txog tej yam ib puag ncig xws li qhov kub thiab txias, thauj khoom, thiab kev thauj mus los ntau zaus kom ua tiav qhov kev hloov pauv ntawm kev khiav thiab ib puag ncig.