1. Cov kev hloov pauv tseem ceeb dab tsi tshwm sim hauv qhov tawv ntawm cov galvanized coils thaum lub sijhawm ua haujlwm qis -kub?
Qhov kub thiab txias muaj ob -fold cumulative nyhuv ntawm tag nrho cov toughness ntawm galvanized coils. Ua ntej, cov hlau matrix ua raws li qhov dav dav qis -kub softening txoj cai- raws li qhov kub thiab txias, qhov ntsuas lub zog (yield zog thiab tensile zog) ntawm cov hlau nce, tab sis nws cov yas deformation muaj peev xwm txo qis thiab nws cov brittleness nce. Qhov tshwm sim no hu ua low-temperature brittleness. Thaum qhov kub thiab txias poob mus rau qee qhov ntau, qhov tawg ntawm cov hlau dheev hloov los ntawm cov pob txha tawg mus rau cov pob txha tawg; qhov kub thiab txias no yog hu ua ductile -kub hloov pauv hloov. Qhov thib ob, txheej txheej galvanized nws tus kheej yog qhov tsis tshua muaj siab rau qhov kub thiab txias: zinc yog qhov kub thiab txias - hlau rhiab heev. Nyob rau hauv qis- qhov kub thiab txias, nws cov qauv siv lead ua tau ruaj khov dua, thiab kev sib txuas sib txuas ntawm lub zog sib txuas ntxiv, txo cov ductility thiab ua rau brittleness ntawm zinc txheej. Qhov no ua rau nws yooj yim dua rau tev lossis tawg thaum khoov thiab ua haujlwm. Hauv lwm lo lus, thaum lub sijhawm ua haujlwm qis - kub, cov hlau matrix ua "nyuaj thiab nkig," thiab cov zinc txheej ua "pob txha." Thaum raug tsim los ua haujlwm xws li txias khoov thiab stamping, cov nyhuv cumulative ua rau muaj kev pheej hmoo ntawm kev tawg tag nrho.
2. Puas yog qhov qis -kub embrittlement mechanisms ntawm steel substrate thiab galvanized txheej zoo tib yam? Dab tsi ntawm kev sib nrig sib cuam tshuam muaj nyob nruab nrab ntawm lawv?
Cov txheej txheem sib txawv, tab sis lawv tuaj yeem ua rau ib leeg puas tsuaj thaum ua haujlwm. Lub hauv paus ua rau qis - kub embrittlement nyob rau hauv cov hlau substrate (lub cev -centered cubic qauv hlau) nyob rau hauv lub zog ua hauj lwm rau dislocation txav ntawm qhov kub thiab txias, thiab muaj zog sib cuam tshuam ntawm interstitial impurity atoms thiab dislocations thiab grain ciam teb, uas drastic tsis muaj zog rau cov ntaub ntawv deformation. Qhov qis- kub embrittlement ntawm zinc txheej (kaw- ntim hexagonal qauv) stems los ntawm nws cov qauv siv lead ua ua nruj dua ntawm qhov kub thiab txias, ib txwm txo nws cov ductility. Kev sib nrig sib cuam tshuam ntawm ob qho tib si thaum lub sij hawm ua yog feem ntau tshwm sim nyob rau hauv cov nram qab no txoj kev: Thaum lub steel substrate undergoes txias dabtsi yog khoov deformation nyob rau hauv qis kub, nws sab nrauv bears ib tug loj tensile hom. Cov txheej zinc, vim nws qhov siab brittleness thiab tsis txaus ductility, tsis tuaj yeem deform synchronously nrog lub substrate, ua rau microcracks los yog blocky tev ntawm txheej. Qhov ntau dua qhov deformation ntawm cov hlau substrate, qhov hnyav dua cov kab mob los ntawm zinc txheej, thiab qhov pib ua ntej ntawm qis - kub embrittlement tawg. Hloov pauv, thaum txheej txheej tsim cov kab nrib pleb, kev ntxhov siab yuav ua rau muaj kev ntxhov siab ntxiv, uas yuav ua rau muaj kev nthuav dav ntxiv ntawm cov hlau substrate, ua rau dhau los ntawm - thickness tsis ua hauj lwm.
3. Kev tawg ntawm galvanized coils thaum lub sijhawm ua haujlwm qis -kub: Puas yog qhov zoo ntawm cov ntawv hlau nws tus kheej yog qhov tseem ceeb tshaj plaws?
Undoubtedly, sab hauv zoo ntawm cov khoom siv hauv paus yog qhov kev txiav txim siab ua ntej kom ua tiav qhov kev ua tiav qis - kub. Txawm nyob rau hauv chav tsev kub, metallurgical tsis xws luag nyob rau hauv lub steel kauj yuav yooj yim ua rau tawg thaum lub sij hawm ua; ntawm qhov kub thiab txias, qhov cuam tshuam tsis zoo ntawm cov teeb meem no tau nthuav dav ntau zaus.
Tshwj xeeb, qhov ua rau tsis ua haujlwm txawv nyob ntawm qib steel. Cov ntaub ntawv tshawb fawb qhia tau hais tias txawm nyob hauv chav tsev kub, tsis zoo - cov ntaub ntawv zoo yuav tawg vim muaj qhov tsis xws luag sab hauv thaum lub sij hawm ntsuas 180℃txias khoov. Metallographic tsom xam pom tias muaj ntau cov khoom sib xyaw ua ke ntawm silicates, sulfides, thiab pwm flux ntawm qhov chaw tawg. Cov inclusions no tsis txaus elongation hauv zos, ua kev ntxhov siab concentration ntsiab lus thaum khoov, ua rau tawg pib. Tsis tas li ntawd, cov qib siab ntau ntawm cov cementite dawb kuj yog ib qho tseem ceeb ntawm kev khoov cov kab nrib pleb hauv Q195C steel, thaum cov qauv banded hnyav ntawm Q355B steel tuaj yeem ua rau delamination thaum shearing, thiab tsis tiav annealing ntawm microstructure hauv Q420XG steel kuj ua rau tsis txaus tag nrho cov khoom siv hauv paus. Nws yog qhov tseeb tias nyob rau hauv qis- qhov kub thiab txias, cov txheej txheem xaiv cov khoom yuav tsum tau nce siab heev- cov kev cuam tshuam me me ntawm cov impurities yuav raug nthuav dav, thiab qhov kev huv thiab sib xws ntawm cov substrate yuav hloov los ntawm "nyiaj txiaj" mus rau "kev ciaj sia hauv paus."
4. Qhov sib txawv ntawm qhov qis -kub ua haujlwm toughness ntawm galvanized coils ntawm cov qib sib txawv thiab cov khoom sib txawv yog qhov tseem ceeb npaum li cas?
Qhov sib txawv yog qhov tseem ceeb heev, feem ntau yog los ntawm kev tsim thiab kev loj hlob ntawm cov hlau qub. Cov pa hluav taws xob zoo tib yam steel substrates nthuav tawm qhov hnyav ntawm qhov hnyav ntawm qhov kub thiab txias, feem ntau poob qis dua qhov kev lees paub qis qis ntawm kev cuam tshuam lub zog ntawm -20℃thiab nthuav tawm qhov muaj feem ntau ntawm cov pob txha tawg ntawm -40℃. Piv txwv li, tsim tshwj xeeb uas tsis tshua muaj - kub resistant galvanized nplooj ntawv qhia kev sib txawv kiag li: ua hauj lwm ib tug tsawg- carbon niobium microalloying muaj pes tsawg leeg tsim, thiab ua tau raws li ib tug uniform, zoo- grained qauv los ntawm kev tswj dov thiab txias, nrog rau ib tug txias loj 1 ntawm lawv txawm grade nyob rau hauv cov kev kho mob. -40℃. Lawv lub zog cuam tshuam ntawm -40℃tsis tsawg dua 34J, thiab lawv Z-kev taw qhia elongation tsis tsawg dua 35%. Tsim nyog rau cov qauv welded thiab cov cheeb tsam txias heev, lawv tuaj yeem siv nyab xeeb hauv cov ntawv thov nrog kev nyab xeeb siab heev, xws li cov qauv tsheb npav. Cov kev tshawb fawb kuj tau pom tias qhov kawg ntawm cov kabmob muaj peev xwm ntawm cov khoom siv galvanized ntawm qhov kub thiab txias tuaj yeem yog li 8-9% siab dua li ntawm chav tsev kub. Qhov no qhia tau hais tias qhov qis-kub toughness tsim ntawm lub substrate yog qhov tseem ceeb ntawm kev txiav txim siab ua tiav lossis tsis ua haujlwm, tsis yog txheej txheej nws tus kheej.
5. Yuav ua li cas ntsuas tau zoo los tiv thaiv kev tawg thaum lub sij hawm galvanized coil ua rau lub caij ntuj no?
Thaum ua cov galvanized coils ntawm qhov kub thiab txias hauv lub caij ntuj no, cov kev tiv thaiv tseem ceeb hauv qab no tuaj yeem ua:
Ua ntej, xaiv cov qib steel uas haum rau qis- qhov kub thiab txias. Yog tias qhov kub ntawm qhov chaw nyob qis dua -20 degree, qhov tseem ceeb yuav tsum tau muab rau kev siv qis- kub tshwj xeeb steel substrates (xws li Q355ND, uas tau dhau los kho micro-alloying), ntau dua li Q235 lossis Q195 substrates.
Qhov thib ob, tswj qhov kub thiab txias ua ntej ua. Ua kev ua haujlwm xws li shearing, xuas nrig ntaus, thiab khoov sab hauv tsev lossis hauv qhov chaw sov sov thaum twg ua tau, zam kev ncaj qha, txias deformation ntawm galvanized kauj hauv qab -10℃. Yog tias kev ua haujlwm yuav tsum tau ua nyob rau hauv qhov chaw qis qis, xav txog qhov nruab nrab preheating ntawm steel phaj, tab sis yuav tsum ceev faj kom tsis txhob overheat kom tsis txhob ua rau lub galvanized txheej.
Thib peb, tswj cov deformation ceev thiab tus nqi. Ceev ceev, tseem ceeb deformation nyob rau hauv qis kub yog feem ntau yuav ua rau tawg. Yog li ntawd, nws raug pom zoo kom txo lub kaum sab xis ntawm ib qho dhau thiab siv "multi-pass progressive forming" txoj kev es tsis txhob "ib- sij hawm ua"; Nyob rau tib lub sijhawm, txo qhov kev ua haujlwm nrawm kom tso cai rau cov khoom siv sijhawm txaus rau micro- kev ntxhov siab so thiab tsis txhob tawg tawg.