Failure Analysis and Prevention Strategies for Rail Transit Cheebtsam
Dab tsi yog hom kev ua tsis tau zoo thiab cov yam ntxwv tseem ceeb ntawm cov tsheb ciav hlau thauj mus los?
Hom kev ua haujlwm tsis zoo ntawm cov tsheb ciav hlau thauj mus los feem ntau suav nrog kev qaug zog tsis ua haujlwm, corrosion tsis ua haujlwm, hnav tsis ua haujlwm, thiab deformation tsis ua haujlwm. Txhua hom muaj cov yam ntxwv tseem ceeb. Kev qaug zog tsis ua hauj lwm yog hom feem ntau. Nws cov yam ntxwv tseem ceeb yog qhov tshwm sim ntawm micro- tawg ntawm cov khoom siv. Raws li tus naj npawb ntawm kev thauj mus los nce, cov kab nrib pleb maj mam nthuav, nws thiaj li ua rau cov khoom tawg. Piv txwv xws li qaug zog tawg ntawm elastic rail clips, kab nrib pleb nyob rau hauv fishplates, thiab tawg ntawm welded rail pob qij txha. Qhov no feem ntau tshwm sim nyob rau hauv cov cheeb tsam ntawm kev nyuaj siab. Cov yam ntxwv tseem ceeb ntawm corrosion tsis ua hauj lwm yog cov tsos ntawm xeb me ntsis, pitting, thiab corrosion pits ntawm cov khoom nto. Hauv cov xwm txheej hnyav, qhov no ua rau thinning ntawm cov khoom thiab txo qis zog. Piv txwv muaj xws li bolt corrosion thiab stripping, taug qab spike corrosion thiab rub{10}} tawm, thiab fishplate corrosion thiab puas. Qhov no feem ntau tshwm sim nyob rau hauv ib puag ncig corrosive xws li av noo thiab ntsev tsuag. Cov yam ntxwv tseem ceeb ntawm kev hnav tsis ua haujlwm yog hnav thiab ua kom puas ntawm qhov chaw sib cuag ntawm cov khoom, ua rau kom muaj qhov deformation thiab tsis haum. Piv txwv xws li hnav rau ntawm qhov chaw clamping ntawm cov phaj siab, hnav ntawm cov ntaub thaiv kev tsheb ciav hlau, thiab hnav ntawm qhov chaw sib cuag ntawm cov phaj phaj. Qhov no feem ntau tshwm sim hauv cov cheeb tsam uas muaj kev sib txhuam tsis tu ncua thiab kev ntxhov siab tsis sib xws. Cov yam ntxwv tseem ceeb ntawm deformation tsis ua hauj lwm yog tias cov khoom poob lawv qhov qub, nthuav tawm khoov, sib tw, los yog kev deformation mus tas li, xws li khoov cov kab nrib pleb, deformed elastic clips, thiab kev deformation mus tas li ntawm cov ntaub qhwv. Qhov no feem ntau tshwm sim los ntawm kev thauj khoom ntau dhau, kev teeb tsa tsis raug, lossis cov khoom siv tsis txaus.
Dab tsi yog cov txheej txheem tseem ceeb thiab cov txheej txheem tseem ceeb rau kev txheeb xyuas qhov tsis ua haujlwm?
Cov txheej txheem tseem ceeb ntawm kev tsom xam tsis ua hauj lwm muaj plaub kauj ruam: "kev soj ntsuam qhov tshwm sim ua tsis tiav- ua tsis tiav ua rau kev tshawb nrhiav- tsis ua hauj lwm kev tshuaj ntsuam xyuas- kev ntsuas kev tiv thaiv," kom ntseeg tau qhov tseeb thiab kev tshuaj xyuas. Ua ntej, kev soj ntsuam tsis ua hauj lwm cuam tshuam nrog kev soj ntsuam qhov zoo li, qhov ntev, thiab qhov tsis xws luag ntawm cov khoom tsis ua tiav siv lub qhov muag liab qab, lub iav tsom iav, lossis cov cuab yeej kuaj kev tshaj lij. Qhov chaw, morphology, thiab qhov hnyav ntawm qhov tsis ua haujlwm raug kaw, thiab hom kev ua tsis tiav (xws li, tawg, corrosion, hnav) raug txheeb xyuas. Qhov thib ob, kev ua tsis tiav ua rau kev tshawb nrhiav suav nrog kev tshuaj xyuas ntau qhov ntev, suav nrog cov khoom siv, kev tsim khoom, kev teeb tsa, kev ua haujlwm ib puag ncig, thiab kev thauj khoom. Qhov no suav nrog kev tshuaj xyuas seb cov khoom puas ua tau raws li cov qauv, seb cov txheej txheem tsim khoom puas yog tus qauv, seb puas muaj kev sib txawv ntawm kev teeb tsa, seb puas muaj kev cuam tshuam ib puag ncig, thiab seb cov khoom puas dhau qhov txwv. Tom qab ntawd, tsis ua hauj lwm mechanism tsom xam, ua ke nrog cov ntaub ntawv xeem (xws li kev ntsuam xyuas cov cuab yeej cuab tam, kev tshuaj ntsuam metallographic, thiab tsis yog{10}}kev kuaj kev puas tsuaj), qhia meej txog lub hauv paus ua rau tsis ua hauj lwm. Piv txwv li, qaug zog tsis ua hauj lwm yog vim muaj kev ntxhov siab ua rau tawg tawm, thaum corrosion tsis ua hauj lwm yog vim electrochemical corrosion ua rau cov khoom siv. Thaum kawg, kev tiv thaiv kev tiv thaiv yog tsim, tsom rau cov hauv paus ntsiab lus nrog cov tswv yim tshwj xeeb hauv kev xaiv xws li kev xaiv, txheej txheem, kev teeb tsa, thiab kev saib xyuas kom tsis txhob muaj qhov tsis zoo sib xws. Cov txheej txheem tseem ceeb suav nrog kev tshuaj xyuas metallographic, tsis yog{14}} kuaj kev puas tsuaj (ultrasonic, magnetic particle), kev ntsuas cov cuab yeej cuab tam, thiab kev kuaj ib puag ncig corrosion, muab cov hauv paus kev tshawb fawb rau kev soj ntsuam tsis ua haujlwm.
Yuav ua li cas tiv thaiv qaug zog tsis ua hauj lwm ntawm cov khoom los ntawm cov khoom optimization?
Cov khoom siv optimization tuaj yeem txhim kho qhov qaug zog ntawm cov khoom thiab tiv thaiv kev qaug zog tsis ua haujlwm. Lub hauv paus tseem ceeb yog xaiv qhov siab - lub zog, siab - toughness, thiab qaug zog - cov ntaub ntawv resistant, thaum optimizing lub sab hauv ntawm cov khoom. Ua ntej, xaiv cov khoom tsim nyog rau cov kab thauj khoom. Hnyav-load thiab siab- cov kab nrawm yuav tsum siab - lub zog hlau alloy, xws li siv 60Si2MnA caij nplooj ntoos hlav steel rau lub caij nplooj ntoos hlav clips, 40Cr alloy steel rau fishplates, thiab U75V siab- lub zog steel rails los txhim kho qhov qaug zog txwv ntawm cov khoom. Thib ob, ua kom zoo dua cov txheej txheem smelting ntawm cov khoom kom txo tau cov impurities sab hauv, kev sib cais, thiab microcracks, ua kom lub cev tsis sib xws thiab txhim kho kev qaug zog. Piv txwv li, cov txheej txheem refining tuaj yeem txo cov sulfur thiab phosphorus cov ntsiab lus hauv cov hlau, tiv thaiv kev ntxhov siab. Thib peb, tsom kev kho cua sov ntawm cov khoom tseem ceeb heev. Piv txwv li, lub caij nplooj ntoos hlav clips tau quenching ua raws li qhov nruab nrab - qhov kub thiab txias, thiab cov phaj ntses tau ua kom zoo li qub los ntawm tempering los ua kom cov nplej zoo dua qub, txhim kho microstructure, thiab txhim kho cov tawv nqaij thiab qaug zog. Tsis tas li ntawd, ntxiv cov ntsiab lus alloying (xws li chromium, manganese, thiab vanadium) rau cov khoom tuaj yeem ua rau nws lub zog thiab tawv, ua rau lub neej qaug zog. Nyob rau tib lub sijhawm, kev kuaj xyuas kom zoo yog qhov tseem ceeb los xyuas kom meej cov khoom ua tau raws li cov lus qhia tshwj xeeb, tiv thaiv kev qaug zog tsis ua haujlwm ntawm nws qhov chaw.
Dab tsi yog qee qhov kev tiv thaiv kev tiv thaiv rau kev tiv thaiv tsis ua haujlwm los ntawm ib puag ncig?
Ib puag ncig yam tseem ceeb (humidity, ntsev tsuag, kub kub, thiab huab cua txias) yog qhov tseem ceeb ua rau cov khoom tsis ua hauj lwm. Cov phiaj xwm kev tiv thaiv yuav tsum tau tsim los ntawm cov yam ntxwv tshwj xeeb ntawm txhua qhov chaw. Rau cov av noo thiab ntsev tsuag corrosive ib puag ncig, lub tswv yim tseem ceeb yog siv los tiv thaiv - kho corrosion. Cheebtsam xws li lub caij nplooj ntoos hlav clips, bolts, thiab taug qab spikes yuav tsum tau kub -dip galvanizing los yog Dacromet txheej los txhim kho corrosion kuj. Nyob rau tib lub sijhawm, txhim kho cov dej ntws los tiv thaiv cov dej los nag thiab tsis tu ncua ntxuav cov ntsev thiab cov khib nyiab los ntawm cov khoom siv los txo cov adhesion ntawm corrosive media. Rau siab - qhov kub thiab txias ib puag ncig, xaiv siab - cov ntaub ntawv kub resistant, xws li siab - kub hloov roj hmab rau rail pads, los tiv thaiv cov khoom softening thiab aging. Txhim kho txoj kev ua pa kom txo qis qhov kub ntawm qhov chaw thiab tsis tu ncua tshuaj xyuas cov khoom rau kev laus, hloov tam sim ntawd. Rau qhov chaw txias heev, xaiv qis- kub resistant thiab cov ntaub ntawv tawv los tiv thaiv khaub thuas- tawg tawg, xws li qis- kub resistant caij nplooj ntoos hlav steel rau lub caij nplooj ntoos hlav clips thiab siab -toughness alloy steel rau khiav spikes. Tshem cov daus thiab dej khov los ntawm txoj kev taug kev los tiv thaiv kev sib tsoo thiab kev xeb ntawm cov khoom, thiab tsis tu ncua tshuaj xyuas cov khoom rau kev puas tsuaj. Tsis tas li ntawd, nyob rau hauv ib puag ncig tshwj xeeb (xws li cov chaw ua lag luam tshuaj lom neeg thiab thaj chaw ntug hiav txwv), tshwj xeeb los tiv thaiv- xeb, siab{19}} kub tiv taus, thiab qis- qhov kub thiab txias tuaj yeem siv los txhim kho ib puag ncig kev hloov pauv thiab tiv thaiv tsis ua haujlwm.
Peb tuaj yeem txo qhov tshwm sim ntawm cov khoom tsis ua haujlwm los ntawm kev ntxiv dag zog rau kev tswj xyuas?
Kev txhim kho kev tswj xyuas kev ruaj ntseg yog qhov tseem ceeb los txo qhov tshwm sim ntawm cov khoom tsis ua haujlwm. Lub hauv paus tseem ceeb ntawm txoj hauv kev no yog tsim kom muaj kev saib xyuas ntawm "kev tshuaj xyuas tsis tu ncua, kev saib xyuas raws sijhawm, thiab hloov pauv thaum ntxov" kom ua tiav kev tswj hwm lub neej tag nrho. Ua ntej, yuav tsum tsim ib txoj kev tshuaj ntsuam xyuas niaj hnub, qhia txog lub voj voog tshuaj ntsuam thiab cov khoom raws li cov khoom siv lub neej thiab taug qab cov xwm txheej ua haujlwm. Piv txwv li, lub caij nplooj ntoos hlav clips thiab bolts yuav tsum tau soj ntsuam txhua txhua 6 lub hlis, thiab rail welded pob qij txha txhua 12 lub hlis. Tsis yog-kev kuaj kev puas tsuaj thiab kev soj ntsuam qhov muag yuav tsum tau siv los txheeb xyuas qhov muaj feem cuam tshuam tsis zoo. Qhov thib ob, kev ua haujlwm tu lub sijhawm yuav tsum tau ua tiav, nruj nreem xoob bolts thiab lub caij nplooj ntoos hlav clips, kho me ntsis corroded los yog hnav qhov chaw, thiab optimizing khiav dej thiab tu kom txo tau tej yam tsis ua hauj lwm. Thib peb, yuav tsum tsim kom muaj ib qho kev hloov khoom siv. Raws li cov khoom siv lub neej ntev thiab kev soj ntsuam xyuas, cov khoom mus txog lawv qhov kev laus yuav tsum tau hloov thaum ntxov. Piv txwv li, lub caij nplooj ntoos hlav clips tom qab 8-10 xyoo ntawm kev siv thiab rail pads tom qab 5-7 xyoo ntawm kev siv, txawm tias tsis pom tseeb tsis ua hauj lwm, yuav tsum tau hloov nyob rau hauv batch kom tsis txhob tam sim ntawd poob lawm. Tsis tas li ntawd, peb yuav ntxiv dag zog rau kev cob qhia cov neeg ua haujlwm tu, txhim kho lawv cov kev txawj ntse, thiab xyuas kom meej tias cov kev sim thiab kev ua haujlwm tau ua tiav raws li tus qauv. Nyob rau tib lub sijhawm, peb yuav tsim cov ntaub ntawv txij nkawm los sau cov kev teeb tsa, kev sim, kev saib xyuas thiab hloov cov khoom seem, kom ua tiav kev taug qab, ntxiv txo qhov tshwm sim ntawm qhov tsis ua haujlwm thiab xyuas kom lub sijhawm ua haujlwm ruaj khov ntawm kev khiav.