Rail Base Material Grade Classification thiab Mechanical Property Adaptation Design
Dab tsi yog qhov sib txawv ntawm cov khoom tseem ceeb qib U71Mn, U75V thiab U78CrV ntawm lub teb chaws tus qauv ntsia?
Qhov sib txawv ntawm qhov sib txawv ntawm peb qib tseem ceeb ntawm lub teb chaws tus qauv tsheb ciav hlau feem ntau yog tshwm sim hauv cov ntsiab lus ntawm cov ntsiab lus tseem ceeb xws li carbon, manganese, vanadium thiab chromium. U71Mn yog qib theem pib nrog cov ntsiab lus carbon ntawm 0.68%-0.78% thiab manganese cov ntsiab lus ntawm 1.10%-1.40%, uas muaj yuav luag tsis muaj vanadium thiab chromium cov ntsiab lus, thiab nws cov qauv tsim tsom mus rau cov khoom siv tshuab yooj yim. U75V nce cov ntsiab lus carbon rau 0.72%-0.82% ntawm lub hauv paus ntawm U71Mn thiab ntxiv 0.04%-0.12% vanadium, uas tuaj yeem tsim cov alloy carbides los txhim kho kev tsheb nqaj hlau. U78CrV yog qib high-end nrog cov ntsiab lus carbon ntawm 0.75% -0.85%, thiab tib lub sijhawm ntxiv 0.30% -0.60% chromium thiab 0.08% -0.15% vanadium. Kev sib xyaw ua ke ntawm ob lub ntsiab lus alloy ntxiv optimizes cov khoom siv. Kev hloov pauv ntawm qhov kev faib ua feem ntawm cov ntsiab lus sib txawv yog ua kom cov khoom siv kho tshuab ntawm txhua qib ntawm kev tsheb nqaj hlau tsim ib qho gradient, hloov mus rau cov kev xav tau ntawm cov kab sib txawv, thiab kev tswj cov ntsiab lus meej ntawm cov ntsiab lus tseem tuaj yeem zam qhov tsis xws ntawm cov ntsia hlau los ntawm qhov tsis sib xws.
Vim li cas siab -vanadium thiab siab- cov khoom siv carbon cov qib nyiam rau cov hlau hauv qab ntawm txoj kab hauv hnyav - cov kab tsheb?
Rails nyob rau hauv hnyav- cov kab thauj khoom dais cov yam ntxwv ntawm lub nra hnyav thiab rov ua dua, thiab siab -vanadium thiab siab- cov pa roj carbon monoxide feem ntau yog vim lawv cov khoom siv zoo heev los hloov kho rau kev ua haujlwm hnyav. Cov ntsiab lus carbon siab tuaj yeem txhim kho lub zog tensile thiab hardness ntawm txoj kev tsheb ciav hlau, txhim kho txoj kev tsheb ciav hlau muaj peev xwm tiv taus cov yas deformation thiab tiv taus qaug zog, thiab zam kev nyuaj siab thiab deformation ntawm lub taub hau tsheb ciav hlau hauv qab hnyav. Vanadium carbide tsim los ntawm kev sib xyaw ntawm vanadium thiab carbon tuaj yeem ua kom zoo dua cov tsheb ciav hlau, txhim kho qhov hnav tsis kam thiab qaug zog ntawm cov khoom siv, thiab txo cov kev tsheb ciav hlau lub taub hau coj los ntawm kev rov ua dua ntawm hnyav - tsheb ciav hlau. Lub zog tawm los thiab lub zog tensile ntawm cov ntsia hlau nrog siab -vanadium thiab siab - cov pa roj carbon qib siab ntau dua li cov qib theem pib, uas tuaj yeem cuam tshuam cov kev ntxhov siab hauv zos los ntawm hnyav hnyav thiab txo qhov tshwm sim ntawm cov kab nrib pleb. In addition, the internal structure of such material rails is denser and the impact toughness is better, which can cope with the frequent wheel-rail impact of heavy-haul lines, extend the service cycle of rails and reduce the frequency of maintenance and replacement.
Dab tsi yog qhov sib txawv ntawm cov khoom siv ntawm cov qauv thoob ntiaj teb UIC60 rail thiab lub teb chaws tus qauv U75V rail?
Cov kev ua tau zoo ntawm cov tub ntxhais kawm sib txawv ntawm UIC60 rail thiab lub teb chaws tus qauv U75V rail yog xav txog peb qhov tseem ceeb: tensile zog, hardness tis thiab hnav tsis kam. Lub zog tensile ntawm UIC60 rail yog hais txog 880-980MPa, me ntsis qis dua 950-1050MPa ntawm lub teb chaws tus qauv U75V, thiab nws tsim tsom ntau dua rau cov yas thiab toughness ntawm cov khoom es tsis muaj zog heev. Nyob rau hauv cov nqe lus ntawm hardness tis, qhov hardness ntawm UIC60 rail lub taub hau yog 280-320HB, thiab lub hardness hloov ntawm rail lub taub hau mus rau rail web yog ntau maj mam; Lub hardness ntawm lub teb chaws tus qauv U75V rail lub taub hau yog 300-350HB, thiab lub hardness yog concentrated nyob rau hauv ua hauj lwm nto ntawm lub tsheb ciav hlau lub taub hau nrog zoo hnav tsis kam. Nyob rau hauv cov nqe lus ntawm hnav tsis kam, lub teb chaws tus qauv U75V muaj 15% -20% siab hnav tsis kam ntawm lub tsheb ciav hlau lub taub hau tshaj UIC60 vim yog ntxiv ntawm vanadium, uas yog tsim nyog rau loj qag hnyav loads, thaum UIC60 muaj zog tiv thaiv qaug zog tawg propagation thiab yog haum rau high-frequency thiab nruab nrab-load European kab ua hauj lwm tej yam kev mob. Qhov kev ua tau zoo sib txawv ntawm ob lub hauv paus pib los ntawm kev faib ua feem ntawm cov khoom siv, ob qho tib si yog kom phim cov kab kev siv raws li lawv cov qauv.
Cov cim tseem ceeb twg yog tsom rau hauv kev ntsuas kev ua tau zoo ntawm kev tsheb nqaj hlau hlau?
Kev ntsuas kev ua tau zoo ntawm kev tsheb nqaj hlau hlau yuav tsum tau tsom mus rau tsib qhov ntsuas tseem ceeb: lub zog tensile, lub zog tawm los, elongation, cuam tshuam toughness thiab hardness, los txiav txim siab seb cov khoom puas ua tau raws li tus qauv. Lub zog tensile thiab lub zog tawm los ncaj qha cuam tshuam txog kev tsheb ciav hlau lub peev xwm los tiv thaiv tensile kev nyuaj siab thiab cov yas deformation, uas yog lub hauv paus ntawm kev tsheb nqaj hlau muaj peev xwm. Cov txiaj ntsig kev xeem yuav tsum ua raws li tus qauv ntu ntawm cov qib sib thooj, thiab qhov sib txawv yuav tsum tsis pub tshaj ± 50MPa. Elongation qhia txog cov plasticity ntawm txoj kev tsheb ciav hlau, thiab cov qauv tsim nyog yuav tsum muaj ntau dua lossis sib npaug li 10% kom ntseeg tau tias txoj kev tsheb ciav hlau yuav tsis raug puas tsuaj los ntawm kev thauj khoom. Kev ntsuas qhov hnyav yog tsom rau kev hloov pauv ntawm txoj kev tsheb ciav hlau mus rau qis - qhov kub thiab txias ua haujlwm, sim ntawm -20℃lossis -40℃, thiab lub zog cuam tshuam yuav tsum muaj ntau dua lossis sib npaug li 30J txhawm rau tiv thaiv kev tawg ntawm txoj kev tsheb ciav hlau hauv qhov chaw qis qis. Kev xeem Hardness feem ntau yog rau qhov chaw ua haujlwm ntawm lub taub hau tsheb ciav hlau, siv Brinell lossis Rockwell hardness txoj kev los xyuas kom meej tias qhov hardness ua tau raws li tus qauv thiab kev faib khoom sib xws, tsis txhob hnav ntau dhau los ntawm qhov tsis txaus hauv zos hardness. Tag nrho tsib qhov ntsuas yuav tsum dhau qhov kev xeem, thiab txhua qhov ntsuas tsis tsim nyog raug txiav txim siab tias tsis tsim nyog hauv paus hlau thiab raug txwv tsis pub muab tso rau hauv kev tsim khoom.
Vim li cas cov khoom tsim ntawm high - tsheb ciav hlau ceev yuav tsum tau coj mus rau hauv tus account ob lub zog siab thiab tsis tshua muaj kev ntxhov siab?
High- cov tsheb ciav hlau ceev tau muaj siab- zaus thiab siab - lub log nrawm- kev tsheb nqaj hlau cuam tshuam thaum lub sijhawm ua haujlwm, thiab cov khoom tsim los suav nrog ob qho tib si lub zog siab thiab tsis tshua muaj kev ntxhov siab hauv lub cev yog qhov yuav tsum tau ua kom muaj kev nyab xeeb thiab kev nyab xeeb. Lub zog siab ua rau txoj kev tsheb ciav hlau los tiv thaiv lub zog thauj khoom thiab kev sib cuag kev ntxhov siab los ntawm kev siab - tsheb ciav hlau ceev, zam kev deformation ntawm yas, corrugation thiab lwm yam kab mob ntawm lub taub hau tsheb ciav hlau, thiab xyuas kom cov kabmob muaj peev xwm thiab hnav tsis kam ntawm txoj kev tsheb ciav hlau. Tsis tshua muaj kev ntxhov siab sab hauv tuaj yeem tiv thaiv kev tsheb ciav hlau los ntawm kev sib tsoo thiab deforming thaum lub sijhawm tsim khoom, tso thiab kev pabcuam, thiab xyuas kom meej qhov ncaj thiab du ntawm txoj kev tsheb ciav hlau. Qhov yuav tsum tau muaj siab - cov kab ceev rau kev khiav smoothness yog ntau dua li cov kab - ceev, thiab me me deformations yuav cuam tshuam rau kev khiav tsheb ciav hlau. Yog tias qhov kev ntxhov siab sab hauv ntawm txoj kev tsheb ciav hlau siab dhau lawm, txawm tias lub zog ua tau raws li tus qauv, cov kab nrib pleb sab hauv yuav raug tsim nyob rau hauv lub sij hawm ntev - vibration load, thiab cov kab nrib pleb yuav yooj yim ua rau kev puas tsuaj thiab kev nyab xeeb. Cov khoom tsim uas siv ob qho tib si tuaj yeem ua rau siab - kev tsheb ciav hlau ceev tsis tsuas yog muaj peev xwm txaus, tab sis tseem muaj kev ruaj ntseg ntawm cov qauv, txo cov nqi kho tom qab thiab hloov mus rau kev ua haujlwm siab ntawm - tsheb ciav hlau ceev.