Qhov twg DH790 zaum hauv GB / T 712 System
GB / T 712 qib tau nyeem ua ob ntu. Tsab ntawv tshaj tawm hais txog cov chav kawm toughness thiab yog li qhov ntsuas kub ntawm qhov kev ntsuas cuam tshuam tau ua: A ntawm 0 degrees C, D ntawm qhov rho tawm 20 degrees C, E ntawm qhov rho tawm 40 degrees C thiab F ntawm qhov rho tawm 60 degrees C. H-series kev xaiv uas ua raws li hais txog qib zog, yog li H790 txheeb xyuas qhov tsawg kawg nkaus ntawm 09 MP lub zog ntawm 7.
DH790 yog li sib txuas ua ke 790 MPa yam tsawg kawg nkaus lub zog muaj zog nrog kev cuam tshuam toughness txheeb xyuas ntawm rho tawm 20 degrees C. Nws yog lub zog siab tshaj plaws uas tau them los ntawm tus qauv, thiab nws lub hom phiaj yog qhov hnyav ntawm cov qauv hauv cov chav uas tseem yuav tsum ua kom pom kev puas tsuaj ntawm qhov kev pabcuam kub. Qhov twg tus qauv tsim kub qis dua, tib lub zog muaj nyob rau hauv cov chav kawm E thiab F toughness, uas tau sim ntawm rho tawm 40 thiab rho tawm 60 degrees C feem.
Mechanical Property Requirements
| Khoom | Kev xav tau rau DH790 | Tswv yim lub ntsiab |
|---|---|---|
| Yam tsawg kawg nkaus yield zog | 790mpa ua | Muaj peev xwm thauj khoom siab heev rau ib chav tsev ntawm ntu, ua kom nyias nyias thiab sib dua |
| Tensile zog | Raws li tau teev tseg rau qib hauv GB / T 712 | Upper thiab qis ciam teb yog ob qho tib si tswj kom khaws ductility thiab ua haujlwm tau zoo |
| Impact toughness | Charpy V-kev ntsuas qhov ntsuas kub ntawm qhov ntsuas kub ntawm qhov ntsuas kub ntawm qhov ntsuas kub ntawm 20 ° C, ntawm qhov nqus lub zog tau teev tseg rau qib | Guards tiv thaiv brittle fracture nyob rau hauv txias marine kev pab cuam |
| Kev xa khoom | Quenched thiab tempered | Tsim cov qauv zoo -cov qauv nplej uas txhawb nqa lub zog siab thiab tawv |
| Kev xav tau tshuaj | Tsawg carbon nrog npib tsib xee, molybdenum, tooj liab thiab micro{0}}alloying ntxiv; tsawg sulfur thiab phosphorus | Sib npaug hardenability, toughness thiab weldability ntawm 790 MPa |
Alloy tsim thiab ua
Ntawm 790 MPa cov npoo ntawm lub zog thiab lub zog yuav nqaim, yog li cov qauv tsim thiab cov dov thiab kev kho cua sov yog tsim ua ke es tsis yog ntawm nws tus kheej. Nickel thiab tooj liab yog siv los txhim kho toughness thiab pab txhawb lub zog yam tsis embrittling lub matrix, molybdenum muab hardenability kom hnyav seem los ntawm - harden, thiab niobium, vanadium thiab titanium ntxiv refine lub grain loj. Thermomechanical processing ua ke nrog quenching thiab tempering yog txoj hauv kev ib txwm, thiab txoj kev txias txias txiav txim siab seb qhov yuav tsum tau ua ke ntawm cov khoom tiav los ntawm tag nrho cov tuab.
Kev tswj hwm impurity yog qhov tseem ceeb ntawm qib no lub zog. Tsawg leej faj thiab phosphorus tiv thaiv los ntawm - thickness ductility thiab txo qhov kev pheej hmoo ntawm lamellar tearing nyob rau hauv cov pob qij txha ruaj khov, thaum ceev nrooj tswj kev tswj xyuas qhov hnyav ntawm vuam kub- thaj tsam cuam tshuam nrog rau lub hauv paus hlau.
Vuam thiab kev tsim kho kev txiav txim siab
Siab - steel zog yuav tsum tau ntau dua kev qhuab qhia nyob rau hauv fabrication, vim hais tias cov khoom uas ua rau nws txaus nyiam kuj yog cov khoom uas yooj yim rau kev puas tsuaj nrog cua sov.
Sib piv cov khoom siv vuam siv rau lub hauv paus hlau lub zog, thiab siv tsawg- hom hydrogen nrog cov ntaub ntawv khaws cia thiab tuav.
Txiav txim siab preheat los ntawm carbon sib npaug, thickness thiab sib koom ua ke, thiab siv nws tsis tu ncua, nrog rau thaum lub sij hawm tack welding.
Tswj cov cua sov tawm hauv lub qhov rais tsim nyog. Lub tshav kub- cuam tshuam thaj tsam ntawm 790 MPa steel yog thaj chaw tseem ceeb rau kev ua kom tawv thiab muag muag.
Npaj cov txheej txheem vuam los tswj cov kev ntxhov siab thiab qhov tsis sib xws, uas tseem ceeb dua nyob rau hauv nyias, siab - lub zog muaj zog dua li cov qauv hull steel.
Tsim nyog cov txheej txheem thiab cov neeg ua haujlwm raws li cov cai siv hauv zej zog kev faib tawm, thiab siv tsis yog - kev ntsuam xyuas kev puas tsuaj rau tag nrho cov uas xav tau rau pawg sib koom.
Xav txog kev qaug zog nrog rau lub zog zoo li qub, txij li qhov hnyav - cov qauv zoo tshaj plaws feem ntau ua haujlwm ze rau lawv cov kev txwv qaug zog.
Daim ntawv thov
DH790 tau teev tseg rau offshore platforms thiab jack- nce cov qauv, sib sib zog nqus- cov khoom siv dej hiav txwv, hnyav- nqa thiab crane Cheebtsam, thiab thauj khoom-cov tswvcuab ntawm siab- cov nkoj ua haujlwm qhov twg txhua tonne ntawm cov qauv nqi them. Tubular cov tswv cuab tuaj yeem tsim tau los ntawm kev sib sau thiab vuam phaj ntawm tib qib, thiab cov seem uas tau raug siv rau qhov chaw nruj thiab lub zog yuav tsum ua tiav qhov hnyav tsawg kawg nkaus. Cov neeg tsim qauv xaiv DH790 es tsis yog cov chav kawm qis dua thaum qhov kev pab cuam qhov kub thiab txias tau ntsuas qhov ntsuas qis 20 ° C tab sis tsis xav tau qhov txias dua -chav kawm toughness ntawm E lossis F variants.
FAQ
Q: DH790 txhais li cas hauv GB / T 712?
D qhia txog cov chav kawm toughness, nrog rau kev ntsuam xyuas ntawm qhov kub ntawm 20 ° C, thiab H790 qhia txog qhov siab - muaj zog series nrog qhov tsawg kawg nkaus tawm lub zog ntawm 790 MPa.
Q: DH790 txawv li cas ntawm cov qib E thiab F ntawm tib lub zog?
Lub zog yuav tsum tau zoo ib yam, tab sis qhov cuam tshuam qhov ntsuas kub sib txawv: rho tawm 20 ° C rau D, rho tawm 40 ° C rau E thiab rho tawm 60 ° C rau F. Cov chav kawm txias yog xaiv rau cov qauv tsim qis dua thiab sib txuas ntau xav tau los tsim.
Q: Vim li cas welding nyuaj dua nyob rau theem no lub zog?
Lub tshav kub- thaj tsam cuam tshuam yog nqaim dua thiab tsis kam ua siab ntev. Cov khoom siv hluav taws xob ntau dhau coarsens cov qauv thiab txo qhov toughness, thaum tsis txaus preheat thiab hydrogen los ntawm cov khoom siv yuav ua rau muaj kev pheej hmoo ntawm qhov txias txias, yog li cov txheej txheem yuav tsum tsim nyog thiab tom qab ntawd ua raws li cov txheej txheem.
Q: Puas yog tom qab-weld kev kho cua sov xav tau?
Tsis yog raws li txoj cai. quenched thiab tempered steel tuaj yeem poob lub zog yog tias kub siab tshaj qhov qub tempering kub, yog li txhua yam kev kho cua sov yuav tsum raug tsim los ntawm kev tsim qauv thiab tswj nyob rau hauv qhov tsim nyog ntau yam.
Q: DH790 puas tuaj yeem tsim rau hauv welded tubular seem?
Yog lawm. Phaj ntawm qib tuaj yeem tsim tau thiab ntev welded, tab sis txoj kev sib sau thiab lub voj voog thermal yuav tsum tau them ob leeg los ntawm cov txheej txheem tsim nyog vim tias lawv cov nyhuv ua ke tuaj yeem txo cov tawv nqaij.
