Oxidation tus cwj pwm ntawm cov ntsia hlau thaum sib tsoo txheej txheem
Thaum lub sij hawm kev sib cuam tshuam ntawm cov abrasives thiab cov ntsia hlau, cov yas deformation ntawm cov ntsia hlau tsim kom muaj cua sov, thiab kev sib txhuam ntawm cov khoom siv abrasives thiab cov khoom siv hluav taws xob kuj ua rau cov khoom sib tsoo. Kev sib tsoo ntawm cov hlau ntsia hlau yog ua nyob rau hauv ib puag ncig ntuj, thiab thaum lub sij hawm sib tsoo, cov khoom siv steel hlau yog inevitably oxidized nyob rau hauv lub tshav kub ntawm kev sib tsoo. Muaj kev sib raug zoo ntawm qhov chaw oxidation ntawm steel rails thiab rail burns. Yog li ntawd, nws yog ib qho tsim nyog los kawm txog oxidation tus cwj pwm ntawm txoj kev tsheb ciav hlau thaum lub sij hawm sib tsoo.
Nws tau raug tshaj tawm tias peb hom kev sib tsoo pob zeb nrog lub zog compressive tau npaj, nrog lub zog ntawm 68.90 MPa, 95.2 MPa, thiab 122.7 MPa, feem. Raws li qhov kev txiav txim ntawm kev sib tsoo pob zeb muaj zog, GS-10, GS-12.5, thiab GS-15 yog siv los sawv cev rau peb pawg ntawm cov pob zeb sib tsoo. Rau cov qauv kev tsheb ciav hlau hauv av los ntawm peb pawg ntawm cov pob zeb sib tsoo GS-10, GS-12.5, thiab GS-15, lawv tau sawv cev los ntawm RGS-10, RGS-12.5, thiab RGS-15. Ua kev sib tsoo hauv kev sib tsoo ntawm 700 N, 600 rpm, thiab 30 vib nas this. Txhawm rau kom tau txais cov txiaj ntsig kev sim ntau dua, cov tsheb ciav hlau sib tsoo pob zeb txais yuav tus pin disc hu rau hom. Txheeb xyuas tus cwj pwm oxidation ntawm txoj kev tsheb ciav hlau tom qab sib tsoo.
Qhov saum npoo morphology ntawm av steel rail tau soj ntsuam thiab soj ntsuam siv SM thiab SEM, raws li qhia hauv Fig.1. Cov txiaj ntsig ntawm SM hauv av rail deg qhia tau hais tias raws li kev sib tsoo pob zeb lub zog nce, cov xim ntawm cov av rail deg hloov ntawm xiav thiab daj xim av mus rau thawj xim ntawm txoj kev tsheb ciav hlau. Txoj kev tshawb no los ntawm Lin et al. pom tias thaum qhov sib tsoo kub qis dua 471 ℃, qhov chaw ntawm txoj kev tsheb ciav hlau zoo li qub xim. Thaum qhov sib tsoo kub nyob nruab nrab ntawm 471-600 ℃, lub tsheb ciav hlau pom lub teeb daj daj, thaum lub sij hawm sib tsoo kub ntawm 600-735 ℃, qhov chaw ntawm txoj kev tsheb ciav hlau qhia tau tias muaj kev kub nyhiab. Yog li ntawd, raws li kev hloov xim ntawm cov av hauv av, nws tuaj yeem suav tias yog lub zog ntawm cov pob zeb sib tsoo txo, qhov sib tsoo kub maj mam nce thiab qib ntawm kev tsheb ciav hlau kub nce. EDS tau siv los txheeb xyuas cov ntsiab lus ntawm cov av steel rail nto thiab cov khib nyiab hauv qab. Cov txiaj ntsig tau pom tias nrog kev nce ntawm kev sib tsoo pob zeb lub zog, cov ntsiab lus ntawm O nyob rau saum npoo ntawm txoj kev tsheb nqaj hlau tau txo qis, qhia txog kev txo qis hauv kev sib txuas ntawm Fe thiab O ntawm qhov chaw ntawm txoj kev tsheb ciav hlau, thiab txo qis hauv qib oxidation. ntawm txoj kev tsheb ciav hlau, raws li qhov sib txawv ntawm cov xim hloov ntawm qhov chaw ntawm txoj kev tsheb ciav hlau. Nyob rau tib lub sijhawm, cov ntsiab lus ntawm O lub ntsiab lus ntawm qhov qis ntawm qhov sib tsoo cov khib nyiab kuj txo nrog qhov nce ntawm kev sib tsoo pob zeb. Nws yog ib nqi sau cia hais tias rau saum npoo ntawm steel rail hauv av los ntawm tib lub pob zeb sib tsoo thiab hauv qab ntawm qhov sib tsoo cov khib nyiab, cov ntsiab lus ntawm O cov ntsiab lus nyob rau saum npoo ntawm lub tom kawg yog siab tshaj qhov qub. Thaum lub sij hawm tsim cov khib nyiab, yas deformation tshwm sim thiab kub yog generated vim compression ntawm abrasives; Thaum lub sij hawm cov txheej txheem ntawm cov khib nyiab tawm, cov hauv qab ntawm cov khib nyiab rub tawm tsam pem hauv ntej kawg ntawm cov abrasive thiab generates tshav kub. Yog li ntawd, kev sib xyaw ua ke ntawm cov khib nyiab deformation thiab kev sib txhuam kub ua rau ntau dua ntawm oxidation nyob rau hauv qab ntawm cov khib nyiab, uas ua rau muaj cov ntsiab lus ntau dua ntawm O.

(a) Tsawg zog sib tsoo pob zeb hauv av steel rail nto (RGS-10)

(b) Nto steel rail av nrog nruab nrab lub zog sib tsoo pob zeb (RGS-12.5)
(c) Siab zog sib tsoo pob zeb hauv av steel rail nto (RGS-15)
Fig. 1. Surface morphology, khib nyiab morphology, thiab EDS tsom xam ntawm steel rails tom qab sib tsoo nrog sib txawv siv ntawm kev sib tsoo pob zeb
Txhawm rau txhawm rau tshawb xyuas cov khoom oxidation nyob rau saum npoo ntawm cov hlau ntsia hlau thiab qhov sib txawv ntawm cov khoom siv oxidation nrog cov qib ntawm kev tsheb ciav hlau kub hnyiab, X-ray photoelectron spectroscopy (XPS) tau siv los txheeb xyuas cov tshuaj hauv lub xeev ntawm cov khoom nyob ze. ntawm av steel rails. Cov txiaj ntsig tau pom hauv Fig.2. Tag nrho spectrum tsom xam cov txiaj ntsig ntawm txoj kev tsheb ciav hlau tom qab sib tsoo nrog qhov sib txawv ntawm cov pob zeb sib tsoo (Fig.2 (a)) qhia tias muaj C1s, O1s, thiab Fe2p peaks nyob rau hauv av rail nto, thiab feem pua ntawm O atoms txo nrog qhov ntsuas kub ntawm qhov chaw tsheb ciav hlau, uas yog raws li cov qauv ntawm EDS tsom xam cov txiaj ntsig ntawm kev tsheb ciav hlau. Vim qhov tseeb tias XPS pom cov ntsiab lus nyob ze ntawm txheej txheej saum npoo (kwv yees li 5 nm) ntawm cov khoom siv, muaj qee qhov sib txawv ntawm hom thiab cov ntsiab lus ntawm cov khoom kuaj pom los ntawm XPS tag nrho spectrum piv rau steel rail substrate. Lub ncov C1s (284.6 eV) feem ntau yog siv los ntsuas qhov sib khi lub zog ntawm lwm cov ntsiab lus. Cov khoom tseem ceeb oxidation nyob rau saum npoo ntawm cov hlau ntsia hlau yog Fe oxide, yog li qhov nqaim spectrum ntawm Fe2p tau txheeb xyuas kom meej. Fig.2 (b) rau (d) qhia qhov nqaim spectrum tsom xam ntawm Fe2p nyob rau saum npoo ntawm steel rails RGS-10, RGS-12.5, thiab RGS-15, raws li. Cov txiaj ntsig tau qhia tias muaj ob lub zog sib txuas ntawm 710.1 eV thiab 712.4 eV, ntaus nqi rau Fe2p3/2; Muaj kev khi lub zog siab kawg ntawm Fe2p1/2 ntawm 723.7 eV thiab 726.1 eV. Satellite ncov ntawm Fe2p3/2 yog ntawm 718.2 eV. Ob lub ncov ntawm 710.1 eV thiab 723.7 eV tuaj yeem raug ntaus nqi los ntawm kev khi lub zog ntawm Fe-O hauv Fe2O3, thaum lub ncov ntawm 712.4 eV thiab 726.1 eV yuav raug ntaus nqi rau lub zog khi ntawm Fe-O hauv FeO. Cov txiaj ntsig tau qhia tias Fe3O4 Fe2O3. Lub caij no, tsis muaj qhov ntsuas siab tshaj plaws tau kuaj pom ntawm 706.8 eV, qhia tias tsis muaj cov ntsiab lus Fe nyob rau hauv av rail nto.

(a) Tag nrho spectrum tsom xam

(b) RGS-10 (xiav)

(c) RGS-12.5 (lub teeb daj)

(d) RGS-15 (thawj xim ntawm steel rail)
Fig.2. XPS tsom xam ntawm cov chaw tsheb ciav hlau nrog qhov sib txawv ntawm qhov kub hnyiab
Qhov feem pua ntawm thaj chaw ncov hauv Fe2p nqaim spectrum qhia tau hais tias los ntawm RGS-10, RGS-12.5 rau RGS-15, thaj tsam ncov feem pua ntawm Fe2 + 2p3 / 2 thiab Fe2 + 2p1 / 2 nce, thaum lub ncov cheeb tsam feem pua ntawm Fe3+ 2p3/2 thiab Fe3 + 2p1/2 txo. Qhov no qhia tau hais tias raws li qib ntawm qhov kub hnyiab ntawm txoj kev tsheb nqaj hlau txo qis, Fe2 + cov ntsiab lus hauv cov khoom oxidation saum npoo nce, thaum Fe3 + cov ntsiab lus txo. Cov khoom sib txawv ntawm cov khoom oxidation ua rau cov xim sib txawv ntawm cov av rail. Qhov siab dua qhov kub ntawm qhov chaw (xiav), cov ntsiab lus ntawm Fe2O3 ntau dua hauv cov oxide; Qhov qis dua ntawm qhov kub hnyiab, cov ntsiab lus ntawm FeO ntau dua.