Qhov sib xyaw ua ke ntawm qhov sib piv ntawm qhov sib piv ntawm cov rail bolts nrog lub sij hawm ntev - lub sij hawm preload tuav ntawm lub fastening system
Vim li cas kev tswj hwm nruj ntawm qhov sib piv ntawm cov khoom siv zog (YSR) xav tau rau kev taug qab bolts, tsis yog tsuas yog nrhiav lub zog tensile siab?
High tensile strength only represents the bolt's fracture limit, while YSR determines its elastic reserve capacity. Track bolts endure long-term alternating vibration loads after tightening; an excessively high YSR (e.g., >0.9) ua rau muaj qhov nqaim heev ntawm kev ua haujlwm, qhov chaw me me lossis cov yas deformation thawb lub ntsia liaj qhov rooj mus rau theem yield, ua rau poob mus tas li. YSR qis heev (piv txwv li,<0.75) means the bolt's tensile strength is underutilized, leading to material waste and excessive elastic deformation. Thus, controlling YSR is key to balancing strength and elasticity and ensuring long-term preload stability.
Dab tsi yog qhov zoo tshaj plaws YSR ntau yam rau kev taug qab bolts nyob rau hauv cov kev pabcuam sib txawv?
Rau cov pa kab bolts, qhov zoo tshaj plaws YSR ntau yam yog0.80-0.85, ntsuas elastic reserves thiab siv cov khoom siv rau nruab nrab vibration loads. Siab- cov kab nrawm nrawm yuav tsum muaj qhov dav dav dua vim muaj kev vibration siab, nrog rau qhov zoo tshaj plaws ntawm0.78-0.82kom tsis txhob muaj zog elasticity los ntawm siab - zaus vibration. Hnyav-haul kab bolts tiv taus cov khoom zoo li qub, yuav tsum muaj zog ntau dua los tiv thaiv cov yas deformation-lawv qhov kev pom zoo yog0.85-0.88, txhim khu kev tiv thaiv overload thaum ua kom elasticity.
Yuav ua li cas hom preload tsis ua hauj lwm tshwm sim nyob rau hauv bolts nrog ib tug ntau heev YSR thaum lub sij hawm kev pab cuam?
Hom tsis ua hauj lwm raug yog"yield-hom preload poob". Nyob rau hauv lub tsheb ciav hlau rov qab cuam tshuam, alternating kev ntxhov siab ntawm lub bolt overlaps nrog thawj preload; Thaum cov kev ntxhov siab sib xyaw ua ke dhau ntawm lub bolt lub zog tawm los, micro-plastic elongation tshwm sim. Qhov no irreversible yas deformation ua rau tsis tu ncua preload decay nyob rau hauv lub sij hawm -txawm tias rov retightening tsis tuaj yeem rov qab pib ua ntej. Thaum kawg, cov bolts ua tsis tiav vim yog cov yas deformation ntau dhau, ua rau cov hlua khi hlua khi - ntau hom kev zais tsis ua haujlwm ntau dua li pob txha, ua rau muaj xwm txheej loj.
Yuav ua li cas "quenching thiab tempering" nyob rau hauv kev kho cua sov precisely tswj lub YSR ntawm khiav bolts?
quenching thiab tempering yog cov txheej txheem tseem ceeb rau YSR tswj. Kho quenching kub thiab tuav lub sij hawm refines tus ntsia liaj qhov rooj tus qauv martensitic, nce tensile zog. Kho tempering kub tswj martensite tempering degree, altering yield zog. Piv txwv li, txhawm rau txo YSR, qhov kub thiab txias tuaj yeem tsim nyog los tsim kom muaj cov qauv tempered sorbite ntau dua, txo cov yield zog nrog me me zog tensile zog. Hauv kev tsim khoom, kev sim orthogonal txiav txim siab cov txheej txheem los xyuas kom meej tias txhua pawg ntawm bolts muaj YSR nyob rau hauv qhov tsim ntau yam.
Yuav ua li cas sai sai tshuaj ntsuam bolts nrog tsis tsim nyog YSR siv torque - lub kaum sab xis nkhaus ntawm -site?
Nyob rau hauv kev ntsuam xyuas bolt nruj, tus tsim nyog YSR bolt nthuav tawm qhov tseeb peb -theem torque-angle nkhaus:"elastic theem - yield theem - ntxiv dag zog", nrog ib tug ruaj khov elastic theem nqes hav thiab ib tug txawv yield plateau. Bolts nrog qhov siab tshaj YSR muaj qhov luv luv elastic theem, yuav luag ncaj qha mus rau theem tawm los uas tsis muaj qhov pom tseeb elastic. Bolts nrog qis qis YSR muaj qhov me me elastic theem txoj kab nqes, nrog rau tus nqi torque ntawm qhov kawg ntawm cov theem elastic deb hauv qab cov qauv tsim. Ntawm -site, portable torque-angle testers tuaj yeem coj cov bolts tuaj; cov khoom siv nrog cov nkhaus txawv txav yuav tsum tau rov ua dua - kev tshuaj xyuas thiab raug txwv tsis pub siv.