Uas alloying caij hauv Q345 hlau muaj qhov cuam tshuam loj tshaj plaws ntawm kev tawv tawv?
Ntawm cov alloy cov ntsiab hauv Q345 hlau, manganese (mn) yog qhov tseem ceeb tshaj plaws cuam tshuam rau kev tawv. Nws lub luag haujlwm tsis yog nce lossis txo qis tawv. Hloov chaw, los ntawm peb lub tswv yim tseem ceeb thiab kev ntsuas lub zog, "" ua kom zoo dua qub ntawm cov pa roj carbon, " Qhov no yog ib qho ntawm qhov sib txawv ntawm Q345 thiab zoo tib yam kev cuam tshuam ntawm manganese ntawm "tus yuam sij rau kev hloov pauv ntawm" muaj zog tab sis brittle "rau" muaj zog tab sis tawv heev "
Q345 steel yog tsim nrog "cov pa roj qes + feem ntau yog manganese" qauv. Manganese nyob rau qhov tsis sib haum ntawm cov pa roj carbon nce thiab cuam tshuam nyuaj, ua rau nws tus kheej hauv qab no:
1. Txo qhov ntsuas kub hloov "thiab hloov kho qis qis - kub nruj
Q345 steel (tshwj xeeb yog Q345D / e qib kawm) feem ntau ua haujlwm hauv qis- lu-}} kub}}} kub} qhov ntsuas kub), thiab qis dua-kev tiv thaiv kub yog qhov ntsuas kev nyab xeeb.
Manganese hloov cov qauv theem hloov pauv - kev tsim tawm ntawm "cov qauv zoo nkauj ntawm" me me ntawm Pearlite. " Tsis tas li ntawd, mangle yog soluble nyob rau hauv ferrite, txo cov lattice qhov tsis xws luag "ntawm qhov tsis tshua muaj cua daj hlob (cleavage fracture yog cov essence ntawm tsawg- kub ua kom tawg). Qhov kawg nyhuv: Cuam Tshuam Q345 Kev Ua Qua Q345 Kev Hloov Hlau "Brittle Transition Kub" (qhov tseem ceeb hloov pauv ntawm qhov zoo rau kev txom nyem). Thaum hloov cov pa kub hloov ntawm cov roj carbon tib si (xws li Q235) yog kwv yees li 0 rau kev sib tsoo hauv tsheb thiab cua thiab cua hlob) tsis muaj tawg txawm tias kub tsawg.
2. Offsetting lub detrimental cuam tshuam ntawm carbon ntawm kev muaj zog, ntsuas "lub zog" thiab "tawv"
Cov pa roj carbon yog ib qho tseem ceeb siv zog ntxiv rau hauv Q345 tab sis ntau dhau ntawm cov txiv kab ntxwv ntawm cov tiaj nyom, tsis muaj zog intergarranular. Thiab ② nce ntxiv Ferrite lattice distortion, kev ntxim nyiam rau micracks. Ob qho tib si ntawm cov xwm txheej no tau txo cov hlau cov tawv (tshwj xeeb tshaj yog cov kev cuam tshuam nyuaj), ua rau "muaj zog tab sis brittle" teeb meem. Manganese tuaj yeem ua kom muaj kev phom sij ntawm cov pa roj carbon ua ob txoj kev:
Manganese cov ntaub ntawv "alloy cementite" (xws li (FE, MN) ₃c) nrog carbon. Cov kev ua kom khov xis no yog softer dua li ntshiab cementite (fe₃c) thiab ntau tusyees faib, zam kev ua "thaj tsam ntawm cov qoob loo ntawm cov qoob loo.
Manganese 'cov teeb meem daws teeb meem zog dua "cov nyhuv yog cov pa roj carbon ntau dua, manganese cuam tshuam rau kev nyuaj ntawm ferrite.
Piv txwv li, yog tias cov pa roj carbon ib leeg yog siv los ua kom muaj zog rau 345 MPa, cov ntsiab lus carbon yuav tsum yog tsawg kawg 0.25%. Txij ntawm no, cov hlau cuam tshuam tawv (ntawm -} 20 degree) yuav tsawg dua 20 j (tsis sib ntsib Q345b yuav tsum tau). Txawm li cas los xij, los ntawm kev ntxiv 1.0-1.6% manganese, cov ntsiab lus carbon monoxide tuaj yeem tswj tau lub zog ua kom tiav (Q345b
Q345 steel feem ntau tsim mus rau hauv cov phaj tuab (piv txwv li, 50-100mm, siv nyob rau hauv siab cov hlab thiab loj steel qauv). Cov tawv nqaij tsis zoo yuav ua rau muaj kev tsim ntawm "coarse ferrite + network txias dua, ua rau muaj kev sib luag dua ntawm" kev ua tsis ncaj sab hauv thiab sab nraud tus tub ntxhais. "
Manganese tseem ceeb ua rau theem hloov pauv ntawm cov hlau (piv txwv li, txhim kho cov neeg ua haujlwm nyuaj). Txawm tias theem cov paib tuab, cov tub ntxhais undergoes txaus sib pauv thaum lub sij hawm txias, yog li tiv thaiv cov detheration ntawm kev nruj me me vim yog coarse nplej. Qhov no tseem yog tus yuam sij rau q345 tuab tuab hla lub "{}}}}}}}}}}}} kub tsis yooj yim tsuas yog ua tsis tiav.
Ii. Kev sib piv nrog lwm cov ntsiab lus: vim li cas manganese lub caij nrog "kev cuam tshuam loj tshaj plaws"?
Lwm cov ntsiab lus hauv Q345 (xws li V, NB, thiab SI) tseem cuam tshuam nyuaj, tab sis lawv cov kev cuam tshuam tsis yog li ntawd ntawm manganese:
Vanadium (V), Niobium (NB), thiab titanium (Ti) Q345. (Piv txwv li, yog tias cov ntsiab lus manganese tsawg dua 0.8%, txawm tias muaj kev sib ntxiv ntawm cov nplej, cov hlau yog qhov tsawg dua 25J.)
Silicon (Si): Low Si content (≤0.55%) has little effect on toughness. However, excessive Si content (>0.55%) tuaj yeem nce txias brittleness thiab immair todness, ua rau nws ib qho kev txwv siab rau kev tswj hwm, ntau dua li cov ntsiab lus tseem ceeb uas txhim kho kev nruj.
Cov pa roj carbon (c): qhov tseem ceeb, nws "tsis zoo nyuaj" thiab tsuas yog ua kom nws cov ntsiab lus (tsawg dua lossis sib npaug rau 0.20%); Nws tsis tuaj yeem txhim kho kev nruj.
Lub ntsiab
Txawm hais tias Q345 steel's suggness (tshwj xeeb tshaj yog muaj tsawg {1} kov cov phiaj xwm thiab cov qauv tuab nyob ntawm qhov tseem ceeb ntawm cov ntsiab lus manganials thiab nws cov teebmeem. Manganese ncaj qha chaw nyob rau qhov teeb meem tseem ceeb ntawm kev ua tiav ob lub zog siab thiab siab tawv los ntawm peb tus tseem ceeb los ntawm peb qhov kev hloov pauv kub, thiab txhim kho cov kev puas tsuaj carbon kev puas tsuaj, thiab txhim kho cov kev puas tsuaj rau cov pa roj carbon Nws yog lub ntsiab lus tseem ceeb hauv kev ua tiav Q345 hlau yog "cov hom phiaj muaj zog thiab tawv" ua tau zoo tshaj plaws ntawm kev sib tw dhau ntawm lwm yam kev sib dhos.