1. Lub luag haujlwm ntawm bolt hardness nyob rau hauv kev siv railway yog dab tsi, thiab hardness ntsuas li cas?
Bolt hardness yog ib qho kev ntsuas ntawm lub ntsia liaj qhov rooj tsis kam rau deformation (xws li, khoov, khawb) nyob rau hauv load- tseem ceeb heev rau kev tiv thaiv lub siab thiab kev co ntawm cov tsheb ciav hlau hla. Cov bolts nyuaj (piv txwv li, chav kawm 10.9 alloy steel) tiv taus hnav thiab shear rog zoo dua, ua rau lawv haum rau qhov siab -load. Txawm li cas los xij, bolts uas nyuaj dhau los ua nkig thiab ua rau tawg, yog li hardness yuav tsum sib npaug nrog toughness.
Hardness yog ntsuas los ntawm covRockwell hardness test-ib txoj hauv kev uas lub pob zeb diamond lossis steel indenter raug nias rau hauv lub ntsia liaj qhov rooj nto nrog lub zog paub. Qhov tob ntawm qhov indentation txiav txim siab tus nqi hardness (xws li, HRC 30–35 rau chav kawm 8.8 bolts, HRC 35–40 rau chav kawm 10.9 bolts). Cov neeg tsim khoom sim txhua pawg ntawm cov bolts kom ntseeg tau tias qhov tawv tawv poob rau hauv qhov kev teev tseg rau lawv qib. Cov tsheb ciav hlau tseem pom -cov bolts thaum lub sijhawm xa khoom kom paub meej tias qhov tawv tawv, vim qhov tsis yog qhov nyuaj tuaj yeem ua rau ua tsis tiav ntxov.
2. Cov kev tsheb ciav hlau ua haujlwm li cas hauv cov cheeb tsam uas muaj qhov kub thiab txias, thiab cov khoom siv twg zoo tshaj?
Kev kub ntxhov ntau zaus (piv txwv li, hnub- hmo ntuj viav vias hauv cov suab puam lossis kev hloov raws caij nyoog) ua rau cov tsheb ciav hlau nthuav dav thiab cog lus, uas tuaj yeem xoob cov txiv ntoo lossis ua rau lub tshuab ntxhua khaub ncaws puas yog tias cov khoom tsis hloov pauv. Hlau ntxhua khaub ncaws (xws li, carbon steel) yog nruj thiab tej zaum yuav tawg yog hais tias expansion/contraction yog heev, thaum uas tsis yog -hlau ntxhua khaub ncaws (xws li, roj hmab) tuaj yeem degrade los ntawm rov stretching.
Cov ntaub ntawv zoo tshaj plaws rau thaj chaw zoo li nocaij nplooj ntoos hlav steel washerslos yogstainless hlau washers. Lub caij nplooj ntoos hlav steel yog elastic- nws nthuav dav thiab cog lus nrog kev hloov pauv kub yam tsis muaj kev tawg, tswj kev siab ntawm cov txiv ntoo. Stainless hlau tsis muaj thermal expansion (nws hloov me me nrog qhov kub thiab txias) thiab tiv thaiv corrosion los ntawm noo noo uas feem ntau nrog kub viav vias. Cov neeg ua haujlwm kuj tsis txhob siv cov yas lossis roj hmab ntxhua hauv cov chaw no, vim lawv degrade sai dua. Los ntawm kev xaiv cov khoom tsim nyog, cov tshuab ntxhua khaub ncaws tseem siv tau txawm tias qhov kub thiab txias tsis tu ncua.
3. Cov railway bolts puas tuaj yeem rov ua dua tom qab lawv siv tsis tau lawm, thiab cov txheej txheem rov ua dua yog dab tsi?
Yog lawm, feem ntau cov railway bolts tuaj yeem rov ua dua, vim lawv tau ua los ntawm cov hlau ferrous (carbon steel, alloy steel, stainless hlau) uas tuaj yeem siv tau zoo heev. Cov txheej txheem rov ua dua muaj peb kauj ruam tseem ceeb:
Sau thiab sorting: Cov bolts uas siv tsis tau raug sau los ntawm cov chaw saib xyuas thiab txheeb los ntawm cov khoom siv (xws li carbon steel vs. stainless hlau) los tiv thaiv kev sib kis.
Kev ntxuav thiab kev npaj: Cov ntsia hlau raug ntxuav kom tshem tawm xeb, pleev xim, lossis roj siv cov khoom sib tsoo, cov kuab tshuaj, lossis cov dej siab siab -. Txhua yam tsis yog-cov khoom hlau (piv txwv li, nylon ntxig rau hauv cov txiv ntoo xauv) raug tshem tawm.
Melting thiab ua: Cov bolts huv si yog yaj nyob rau hauv lub cub tawg ntawm qhov kub thiab txias (1,500-1,600 degree) los ua cov hlau molten, uas yog cam khwb cia rau hauv cov hlau ingots tshiab. Cov ingots no ces dov los yog forged rau hauv cov khoom tshiab-nrog rau cov tshiab railway bolts, steel siv, los yog automotive qhov chaw.
Recycling railway bolts txo cov khib nyiab, txuag cov ntaub ntawv raw (xws li, hlau ore), thiab txo qis zog siv piv rau kev tsim cov bolts tshiab ntawm cov hlau nkauj xwb. Nws yog ib qho kev coj noj coj ua uas tau txais los ntawm ntau txoj kev tsheb ciav hlau thoob ntiaj teb.
4. Dab tsi yog qhov txawv ntawm qib 5 thiab qib 8 railway bolts (imperial standard), thiab thaum twg siv?
Qib 5 thiab qib 8 yog qib imperial zog rau kev tsheb ciav hlau bolts, siv feem ntau hauv Asmeskas thiab Canada (raws li AREMA cov qauv):
Qib 5 bolts: Ua los ntawm nruab nrab- carbon steel tshav kub- kho kom muaj zog tensile ntawm 120,000 psi (827 MPa) thiab lub zog tawm ntawm 92,000 psi (634 MPa). Lawv haum rau cov qauv neeg caij tsheb, kab kab, thiab cov ntoo pw tsaug zog- ntsuas lub zog thiab tus nqi.
Qib 8 bolts: Ua los ntawm cov hlau alloy (nrog chromium thiab molybdenum) cua sov- kho kom lub zog tensile ntawm 150,000 psi (1,034 MPa) thiab lub zog tawm ntawm 130,000 psi (896 MPa). Lawv muaj zog dua, hnav ntau dua- tiv taus, thiab siv hnyav- cov kab thauj khoom thauj, siab - txoj kev tsheb ciav hlau ceev, thiab cov tsheb ciav hlau sib koom ua ke- thaj chaw nrog cov khoom hnyav.
Qib 5 bolts yog feem ntau nyob rau hauv imperial - cov qauv kev tsheb ciav hlau rau kev siv txhua hnub, thaum qib 8 bolts tau tshwj tseg rau cov ntu tseem ceeb uas yuav tsum muaj lub zog siab tshaj plaws. Qib yog cim rau ntawm lub taub hau ntsia liaj qhov rooj (xws li, peb kab rau qib 5, rau kab rau qib 8) kom paub yooj yim.
5. Yuav ua li cas railway ceev tiv thaiv cov khib nyiab los ntawm kev nkag mus rau hauv xov, thiab dab tsi tsim pab nrog qhov no?
Cov khib nyiab (piv txwv li, av, xuab zeb, pob zeb me) nkag mus rau hauv cov txiv ntoo xov tuaj yeem ua rau ntes, stripping, lossis corrosion-yog li cov txiv ntoo hauv tsheb ciav hlau siv cov qauv tshwj xeeb los thaiv cov khib nyiab:
Kaw-end (cap) txiv ntseej: Cov no muaj cov khoom saum toj kawg nkaus uas npog cov ntsia liaj qhov rooj ntawm cov xov, tiv thaiv cov khib nyiab los ntawm kev poob rau hauv cov txiv ntoo. Lawv siv nyob rau hauv cov plua plav los yog qias neeg xws li qhov av lossis cov suab puam.
Flanged txiv ntseej: Cov ua tau - nyob rau hauv flange ua raws li ib tug barrier, thaiv cov khib nyiab los ntawm kev nkag mus rau qhov sib txawv ntawm cov txiv ntseej thiab cov khoom siv khiav.
Xov seals: Qee cov txiv ntoo muaj cov roj hmab los yog ua npuas ncauj foob nyob ib ncig ntawm lub hauv paus uas compresses thaum nruj, tsim kom muaj kev sib khi nruj tiv thaiv cov khib nyiab.
Slotted txiv ntoo nrog cotter pins: Tus pin cotter tsis tsuas yog xauv lub txiv ntoo tab sis tseem npog lub qhov, txo cov khib nyiab nkag.
Cov qauv tsim no txo cov khib nyiab pov tseg, khaws cov xov kom huv thiab xyuas kom cov txiv ntoo tuaj yeem raug tshem tawm yooj yim rau kev saib xyuas. Tsis tas li ntawd, cov neeg ua haujlwm feem ntau txhuam cov txiv ntoo thaum kuaj xyuas kom tshem tau cov khib nyiab xoob.