Qhov cuam tshuam Toughness ntawm Track Spikes thiab lawv hloov mus rau Dynamic Loads hauv Hloov Chaw
Yuav ua li cas dynamic cuam tshuam loads nyob rau hauv lub hloov chaw txawv ntawm cov nyob rau hauv ib tug zoo tib yam kab, thiab yog vim li cas yuav tsum tau ntau dua toughness yuam rau spikes?
Hloov chaw muaj cov xwm txheej tshwj xeeb xws li kev hloov tsheb ciav hlau, kev cuam tshuam ntawm lub log flange, thiab taw tes tshuab ua haujlwm; lub amplitude ntawm dynamic cuam tshuam loads yog 3-5 npaug ntawm cov kab zoo tib yam, nrog rau ntau yam cuam tshuam pulses. Spikes ntawm cov kab zoo tib yam feem ntau dais cov khoom zoo li qub thiab qis- zaus vibrations, thaum hloov spikes ua rau muaj kev cuam tshuam loj heev hauv milliseconds. Kev cuam tshuam tsis txaus ua rau cov pob txha tawg (tsis yog qaug zog tawg) nyob rau hauv cov kev cuam tshuam ib ntus-qhov kev tsis txaus siab tam sim no cuam tshuam rau kev hloov geometry, ua rau muaj kev sib tsoo tsheb.
Daim ntawv puas zoo li cas tshwm sim nyob rau hauv kev hloov spikes nrog tsis txaus cuam tshuam toughness?
Daim ntawv ib txwm yog "ib qho-lub sij hawm brittle fracture," characterized by flat, crystalline fracture deg tsis pom tseeb qaug zog striations. Kev puas tsuaj feem ntau tshwm sim ntawm thaj chaw hloov pauv ntawm lub shank thiab lub taub hau, lossis ze rau qhov sib cuam tshuam ntawm tus neeg sawv cev thiab cov ntsia hlau loj. Qhov kev puas tsuaj no feem ntau tshwm sim sai li sai tau thaum cov tsheb ciav hlau hla qhov hloov pauv, tsis muaj kev ceeb toom ua ntej. Tsis zoo li qaug zog pob txha nyob rau hauv cov kab zoo tib yam spikes, brittle fracture yog tshwm sim los ntawm kev cuam tshuam lub zog ntau tshaj qhov spike lub toughness txwv; post- tawg, qhov ntsia hlau tam sim poob lub peev xwm thauj khoom, ua rau muaj kev phom sij ntau dua.
Yuav ua li cas txhawm rau txhim kho qhov cuam tshuam ntawm qhov toughness los ntawm kev xaiv cov khoom siv thiab kev kho cua sov?
Cov khoom siv- ntse, qis- carbon alloy steel (piv txwv li, 20MnTiB) hloov cov nruab nrab zoo tib yam - carbon steel- cov pa roj carbon tsawg ua kom cov matrix toughness, thaum alloying ntsiab txhim khu lub zog. Kev kho cua sov txais yuav "quenching thiab tempering + deg hardening" ua ke: quenching thiab siab -kub tempering daim ntawv tawv tempered sorbite nyob rau hauv cov tub ntxhais, thaum nto hardening txhim kho shank nto hardness thiab hnav tsis kam. Qhov no "nyuaj sab nrauv, tawv core" microstructure ua rau spikes los tiv thaiv hnav thiab tiv thaiv kev cuam tshuam ib ntus, ua rau muaj kev cuam tshuam loj heev.
Suav thiab thoob ntiaj teb cov qauv sib txawv li cas rau qhov yuav tsum muaj zog toughness rau kev hloov- tshwj xeeb spikes?
Suav cov qauv tau teev tseg tias qhov cuam tshuam toughness (Akv tus nqi) ntawm kev hloov- tshwj xeeb spikes yuav tsum tsis pub tsawg dua 40J ntawm chav sov thiab 27J ntawm -20℃. Cov txheej txheem thoob ntiaj teb zoo li BS EN 14662 tsim cov kev cai nruj dua: Akv Ntau dua lossis sib npaug ntawm 50J ntawm chav sov thiab Ntau dua lossis sib npaug rau 35J ntawm -40 degree, nrog ntau yam kev ntsuas cuam tshuam yuav tsum tsis txhob cuam tshuam ib leeg. Qee cov qauv thoob ntiaj teb kuj tseem hais txog qhov tsawg kawg nkaus pob txha toughness (KIC) tus nqi los tiv thaiv kev tawg sai sai txawm tias muaj qhov tsis xws luag.
Yuav ua li cas txiav txim siab ua ntej ntawm -qhov chaw seb puas muaj kev cuam tshuam qhov hnyav raws li cov qauv siv cov kev sim yooj yim?
Hauv -qhov chaw, ib qho yooj yim "poob qhov hnyav qhov kev sim" tuaj yeem siv rau kev sim ntsuas. Txhim kho qhov ntsia hlau loj hauv lub xeev kev teeb tsa tiag tiag, poob ib qho hnyav ntawm qhov siab uas tau xaiv los cuam tshuam rau saum toj kawg nkaus, thiab saib xyuas kev puas tsuaj. Qhov me me deformation yam tsis muaj pob txha qhia tau tias muaj peev xwm cuam tshuam toughness; brittle fracture qhia tias tsis ua hauj lwm. Tsis tas li ntawd, txheeb xyuas cov pob txha tawg: ib qho chaw fibrous nrog cov yas deformation qhia tau hais tias zoo toughness, thaum lub smooth, crystalline nto qhia tias tsis txaus toughness.