Fastenersyog ib hom ntawm cov khoom siv kho tshuab dav siv rau kev sib txuas ceev. Fasteners yog dav siv nyob rau hauv ntau yam lag luam, nrog rau cov tshuab, khoom siv, tsheb, railways, thiab lwm yam. Nws cov yam ntxwv yog ntau yam specifications, ntau yam kev ua tau zoo thiab kev siv, thiab qib siab ntawm standardization, serialization, thiab generalization. Thaum lub fastener tsis ua haujlwm, nws tuaj yeem muaj qhov tshwm sim loj. Yog li ntawd, nws yog ib qho tsim nyog los ntxiv dag zog rau kev tsom xam ntawm qhov ua rau lub fastener tsis ua hauj lwm thiab nrhiav kev txhim kho cov kev ntsuas. Raws li nws txoj kev nkag siab ntawm kev paub fastener, Xiaorui xav qhia rau txhua tus neeg:
1. Nto quenching tawg
Nto quenching cracks hais txog cov kab nrib pleb uas tshwm sim thaum lub sij hawm quenching txheej txheem los yog thaum lub sij hawm chav tsev kub txheej txheem tom qab quenching, qhov kawg ntawm uas kuj hu ua aging tawg. Thaum lub sij hawm quenching txheej txheem, thaum qhov kev ntxhov siab uas tsim los ntawm quenching yog ntau dua li lub zog ntawm cov khoom nws tus kheej thiab tshaj cov yas deformation txwv, nws yuav ua rau cov khoom tawg. Quenching cov kab nrib pleb feem ntau tshwm sim sai tom qab qhov pib ntawm martensitic transformation, thiab kev faib ntawm cov kab nrib pleb tsis ua raws li qee yam qauv. Txawm li cas los xij, lawv feem ntau ua rau ntawm cov ces kaum ntse thiab kev hloov pauv tam sim ntawd hauv ntu ntu ntawm lub workpiece. Quenching kab nrib pleb tshwm sim los ntawm ceev ceev nyob rau hauv lub martensitic transformation cheeb tsam yog feem ntau transgranular thiab muaj ncaj kab nrib pleb uas tsis muaj ceg nyob ib ncig ntawm lawv.
Cov kab nrib pleb uas tshwm sim los ntawm qhov kub siab quenching cua sov yog faib raws cov nplej, nrog cov ntse ntse thiab nplua tawg kawg thiab cov yam ntxwv overheating. Cov koob ntxhib zoo li martensite tuaj yeem pom hauv cov qauv hlau, thiab eutectic lossis angular carbides tuaj yeem pom hauv cov cuab yeej hlau. High carbon steel workpieces nrog decarburization nto yog feem ntau ua rau kev sib tsoo network tom qab quenching. Qhov no yog vim hais tias lub ntim nthuav dav ntawm decarburization txheej thaum lub sij hawm quenching thiab txias yog me dua li ntawm qhov chaw uas tsis yog decarburized, thiab cov khoom nto yog rub thiab tawg mus rau hauv ib lub network zoo vim qhov nthuav ntawm qhov chaw. quenching cov kab nrib pleb ntawm qhov chaw tuaj yeem ua rau tam sim ntawd ntsia liaj qhov rooj tawg, thiab qhov chaw ntawm cov pob txha no nyob ntawm qhov chaw.
2. Torque tshaj qhov txwv
Torque tswb feem ntau tshwm sim thaum lub sij hawm sib dhos txheej txheem ntawmboltsuas tswj torque los ntawm lub kaum sab xis txoj kev.
Cov hom kev ua tsis tiav thiab yog vim li cas rau tshaj qhov txwv torque ntawm fasteners suav nrog:
(1) Tom qab sib dhos, qhov kawg torque ntawm cov khoom yog siab dua li kev tswj hwm sab saud lossis qis dua qhov kev tswj qis. Yog vim li cas yog qhov sib dhos torque tswj ntau yam ntawm cov khoom tsis tsim nyog, tshwm sim raws li kev teeb tsa kev tswj hwm me me dhau lawm, thiab kev tswj hwm kev hloov pauv nce lossis nqis.
(2) Tsis yog ua ntej nruj rau lub kaum sab xis preset, torque ncav cuag lub tswb txwv sab saud. Yog vim li cas yog qhov kev sib txhuam coefficient ntawm cov khoom lawv tus kheej tshaj qhov txwv sab sauv, kev sib txhuam coefficient ntawm cov khoom ntau tshaj qhov txwv sab sauv, thiab kev cuam tshuam ntawm cov khoom ua rau muaj kev nce ntxiv hauv kev sib dhos torque.
(3) Kev teeb tsa ib txwm, torque qis txwv lub tswb. Yog vim li cas yog tias qhov kev sib txhuam coefficient ntawm nws tus kheej tshaj qhov qis qis los yog qhov sib txhuam coefficient ntawm qhov haum tshaj qhov qis qis, thiab qhov haum torque ntawm qhov yog ntau dua qhov pib torque (piv txwv li kev siv torque loj heev) thaum screwing nyob rau hauv, uas yog feem ntau nyob rau hauv nruj nreem kaw.
3. Hydrogen embrittlement
Fasteners yog nquag rau hydrogen embrittlement, uas yog lub ntsiab ua rau fastener puas. Hydrogen embrittlement yog qhov tshwm sim uas hydrogen atoms nkag mus thiab nthuav dav thoob plaws tag nrho cov khoom siv matrix. Thaum hydrogen atoms nkag mus rau hauv cov khoom siv matrix, lattice distortion tshwm sim, cuam tshuam cov thawj lub xeev sib npaug thiab ua rau nws yooj yim rau tawg nyob rau hauv sab nraud rog. Thaum lub load sab nraud yog siv rau lubntsia hlau, hydrogen atoms tsiv mus rau thaj chaw muaj kev ntxhov siab heev, ua rau muaj kev ntxhov siab tseem ceeb ntawm cov ntug ciam teb thiab ua rau tawg ntawm cov khoom siv lead ua ntawm lub fastener. Thaum fasteners muaj hydrogen tseem ceeb ua ntej kev teeb tsa, lawv yuav tawg hauv 24 teev. Nws yog tsis yooj yim sua kom twv seb thaum twg hydrogen yuav tawg tom qab nkag mus rau lub fastener.
4. Kev ntsuas kev txhim kho
4.1 Kev ntsuas los tiv thaiv nto quenching tawg:
(1) Tsim nyog kho qhov sib txawv ntawm qhov induction quencher thiab workpiece, nruj me ntsis xaiv qhov tsim nyog nruab nrab zaus fais fab mov tsis thiab quenching txheej txheem tsis raws li tus txheej txheem yuav tsum tau, xyuas kom meej qhov kub thiab txias ntawm cov khoom ncig, thiab tiv thaiv lub zos kub los ntawm tshaj qhov qub. quenching kub.
(2) Txhim kho cov qauv ntawm cov quenching inductor los ntawm kev hloov cov txheej txheem hla ntu ntu ntawm sab saum toj thiab tus Tsov tus tw kawg ntawm lub inductor mus rau ib qho qauv duab plaub, txo cov cua kub ceev ntawm qhov kawg thiab tus Tsov tus tw inductors, thiab tiv thaiv qhov kawg. thiab tus Tsov tus tw los ntawm cua sov sai heev, dhau ntawm cov txheej txheem tswj qhov kub thiab txias, thiab ua rau kub kub, ua rau tawg.
(3) Txo tus naj npawb ntawm cov hlau nplaum conductive nyob rau hauv quenching hloov chaw ntawm quenching sensor thiab tsim nyog txo cov cua sov hauv cheeb tsam ntawd.
(4) Kev siv lub preheating cua sov cua txias quenching txoj kev los xyuas kom meej cov cua kub ntawm cov khoom.
(5) Ua kom ntev lub sijhawm txias tom qab cua sov nruab nrab.
(6) Siv tus kheej tempering. Ua raws li cov txheej txheem kev tsis sib xws, tsim nyog tswj lub siab, ntws tus nqi, ntsuas kub, thiab lub sijhawm txias ntawm lub quenching coolant. Tom qab tso tseg cov tshuaj tsuag, siv cov hluav taws kub uas seem ntawm cov khoom ua haujlwm kom nce qhov kub ntawm cov txheej txheem hardened, yog li ua tus kheej tempering kom muaj qhov siab tawv thiab hnav tsis kam, ua kom lub sijhawm ruaj khov ntawm cov qauv quenching, thiab txo qhov siab tensile kev nyuaj siab.
4.2 Torque system
Txoj kev tswj torque yog thawj zaug kom nrujntsia liaj qhov roojmus rau ib tug me me torque, feem ntau yog 40% ~ 60% ntawm lub zawm torque (txiav txim siab tom qab cov txheej txheem validation), thiab ces pib los ntawm qhov no taw tes rau zawm lub kaum sab xis tswj txoj kev. Txoj kev no yog ua raws li lub kaum ntse ntse, qhov twg lub ntsia liaj qhov rooj ua rau qee qhov axial elongation thiab lub connector yog compressed. Lub hom phiaj ntawm kev ua qhov no yog kom nruj cov bolts mus rau hauv qhov chaw tiv tauj nruj thiab kov yeej qee qhov tsis muaj axial clamping fort yog tsim los ntawm kev sib hloov kaum. Tom qab xam lub kaum sab xis, qhov cuam tshuam ntawm kev sib txhuam ntawm lub axial clamping quab yuam tsis muaj lawm, yog li nws qhov tseeb yog siab dua li qhov yooj yim torque tswj txoj kev. Lub ntsiab lus tseem ceeb ntawm txoj kev tswj torque yog ntsuas qhov pib ntawm lub kaum sab xis. Thaum lub kaum sab xis tig no tau txiav txim siab, qhov kev nruj nruj nruj tuaj yeem ua tiav.
4.3 Kev tiv thaiv kev tiv thaiv rau hydrogen embrittlement
(1) Ib txwm electroplating thiab nruj hydrogen tshem tawm. Kev siv qhov thim rov qab ntawm hydrogen hauv cov hlau thiab kev kho dehydrogenation ntawm electroplated bolts yog ib txoj hauv kev tseem ceeb los txo lossis tshem tawm hydrogen embrittlement. Thaum ua tiav, muab cov electroplated steel bolts rau hauv qhov cub kom sov. Lub ci kub yog li 200 ° C, thiab lub sij hawm ci txawv nyob ntawm seb lub zog ntawm cov hlau. Lub zog siab dua, lub sijhawm ci ntev dua. Cov hydrogen nyob rau hauv cov khoom siv bolt tsim hydrogen overflow ntawm qhov kub thiab txias, ua tiav lub hom phiaj ntawm kev tshem tawm hydrogen.
(2) Tsawg hydrogen embrittlement electroplating. Tsawg hydrogen embrittlement electroplating yog txheej txheem tsim nyob rau hauv 1960s thiab 1970s rau kev kawm txog hydrogen embrittlement nyob rau hauv aircraft qhov chaw, nrog rau tsawg hydrogen embrittlement cadmium plating, tsawg hydrogen embrittlement cadmium titanium plating, tsawg hydrogen embrittlement zinc plating, thiab lwm yam. Kev ntxhov siab nyem tempering ua ntej plating, thiab tsis tuaj yeem ntxuav cov kua qaub uas muaj zog acid. Hloov chaw, sandblasting yuav tsum tau siv los tshem tawm cov nplai oxide thiab cov av hauv av, lossis kev kho cua sov yuav tsum tau siv los tiv thaiv kev tsim ntawm oxide nplai. Thaum lub sij hawm electroplating txheej txheem, ntawm ib sab, lub plating tov mis yog hloov, thiab ntawm qhov tod tes, tus nqi adsorption ntawm hydrogen hais yog txo los ntawm kev txo qhov voltage thiab nruj me ntsis tswj qhov ceev tam sim no. Cov txheej txheem tom ntej tseem yuav tsum tau ua kom nruj rau kev tshem tawm hydrogen, nrog lub sijhawm tshem tawm hydrogen tsawg kawg yog 18 teev.
