API 5L yog cov kav dej steel qauv tsim los ntawm American Petroleum Institute, thiab L415N yog ib qho ntawm nws cov qib steel. Hauv nws lub npe, "L" sawv cev rau cov raj xa dej, "415" qhia qhov tsawg kawg nkaus lub zog ntawm 415 MPa, thiab "N" qhia txog kev xa khoom hauv qhov xwm txheej. Cov hlau no muaj cov yam ntxwv hauv qab no:
- Lub zog siab: Cov khoom muaj zog thiab tensile ua tau raws li qhov yuav tsum tau ua rau ntev - nrug, siab - kev thauj mus los.
- Zoo toughness: Tswj qhov cuam tshuam los ntawm qhov kub thiab txias, haum rau siv nyob rau sab qaum teb.
- Corrosion tsis kam: Txhim kho kev tiv thaiv rau hydrogen sulfide corrosion los ntawm kev sib ntxiv ntawm cov kab hlau rhuav (xws li niobium thiab vanadium).
Chemical Composition Design Nta ntawm L415N Pipeline Steel
L415N steel yeeb nkab txais yuav qis -carbon microalloying muaj pes tsawg leeg tsim lub tswv yim, ua kom lub zog thaum tseem xav txog qhov zoo weldability thiab toughness. Tus qauv -cov tshuaj muaj pes tsawg leeg tshwj xeeb yog: Carbon (C) Tsawg dua lossis sib npaug rau 0.16%, Manganese (Mn) Tsawg dua lossis sib npaug li 1.60%, Silicon (Si) Tsawg dua lossis sib npaug li 0.45%, Phosphorus (P) Tsawg dua lossis sib npaug li 0.025%, Sulfur (S) tsawg dua 0.1%. Qhov qis-carbon, siab{11}}manganese tsim no muab cov hlau qis dua carbon sib npaug (feem ntau CEIIW Tsawg dua los yog sib npaug rau 0.40%), txhim kho weldability.
Cov ntsiab lus microalloying ua lub luag haujlwm tseem ceeb hauv L415N steel. Los ntawm kev ntxiv cov ntsiab lus tsim nyog xws li niobium (Nb), vanadium (V), thiab titanium (Ti) (feem ntau yog tag nrho 0.05%-0.15%), nplua-grain ntxiv dag zog thiab nag lossis daus muaj zog ua tiav. Cov ntsiab lus no muaj txiaj ntsig zoo inhibit austenite grain kev loj hlob, kho qhov kawg microstructure, thiab txhim kho cov hlau lub zog, toughness, thiab tsis kam rau brittle puas.
Mechanical Properties ntawm L415N Pipeline Steel
Cov khoom siv ntawm L415N pipeline steel nruj me ntsis ua raws li ISO 3183 tus qauv, nrog rau cov kev cai raws li hauv qab no: yield zog 415-565 MPa, tensile zog 520-760 MPa, yield-to-tensile ratio Tsawg tshaj 3 los yog sib npaug rau 0. 20%. Hauv kev tsim khoom tiag tiag, los ntawm kev ua kom zoo dua, cov ntsuas kev ua tau zoo no feem ntau nyob hauv qhov zoo tagnrho. Cov ntaub ntawv pov thawj qhia tau hais tias lub zog tawm los ntawm cov khoom lag luam feem ntau yog nyob rau hauv thaj tsam ntawm 450-500 MPa, tensile lub zog 530-620 MPa, thiab elongation tuaj yeem ncav cuag 23% -30%, nthuav tawm zoo heev lub zog-ductility tshuav.
Toughness yog ib qho tseem ceeb qhia txog kev ua tau zoo rau L415N pipeline steel. Tus txheej txheem yuav tsum muaj Charpy V-qhov cuam tshuam lub zog tsis tsawg dua 40 J (qhov nruab nrab ntawm peb qhov qauv) ntawm 0 degree, nrog rau ib qho qauv tsis tsawg dua 30 J. High- cov khoom zoo feem ntau ua tau zoo tshaj qhov yuav tsum tau muaj nyob rau hauv lub zog muaj zog, tuav lub zog cuam tshuam ntau dua 60 J txawm nyob ntawm -20℃ugh-temperature. Rau cov raj xa dej siv hauv cov cheeb tsam txias xws li Arctic, kev kho tshwj xeeb tuaj yeem siv los xyuas kom muaj kev cuam tshuam lub zog tsawg kawg yog 40J ntawm -40 degree, lav kev nyab xeeb kev ua haujlwm hauv huab cua.
Deformation kuj yog lwm yam tseem ceeb ntawm L415N pipeline steel. Los ntawm kev tswj lub zog ntawm qhov sib piv (feem ntau yog 0.80-0.88) thiab tsis sib xws elongation (Ntau dua lossis sib npaug li 8%), cov yas deformation muaj peev xwm txaus yog xyuas kom meej thaum lub raj xa dej thiab kev ua haujlwm. Rau cov yeeb nkab seem uas muaj feem cuam tshuam rau geological kev puas tsuaj, siab dua strain hardening Performance index (n nqi Ntau dua los yog sib npaug rau 0.10) thiab siab dua strain hardening muaj peev xwm kuj yuav tsum tau tiv thaiv cov kab mob loj los ntawm kev hloov hauv av.
Daim ntawv thov thiab qhov zoo
Roj thiab roj tsheb thauj mus los
Ntev -Ntaus Pipelines: Tiv thaiv qhov siab tshaj 10 MPa thiab hloov mus rau ib puag ncig xws li -30℃txog 60℃.
Offshore Platforms: Resistant mus rau seawater corrosion, nrog ib tug reinforced pob zeb counterweight txheej tiv thaiv dej hiav txwv tam sim no ntawm 15 m / s.
Cov khoom siv tshuaj thiab hluav taws xob
Reaction Vessels thiab Heat Exchangers: Resistant to high temperatures (Ntau dua los yog sib npaug rau 450 degree) thiab kev kub siab (Ntau dua lossis sib npaug li 30 MPa), ua kom ntev - haujlwm ruaj khov.
Boilers thiab Chav Turbines: Siab- lub zog muaj zog kev txhawb nqa kom tiv taus siab - qhov kub ntawm qhov yaig.
Cov xwm txheej tshwj xeeb Geological
High-Altitude Cold Regions: -30℃cuam tshuam toughness ua kom muaj kev nyab xeeb ntawm cov kav dej hauv permafrost.
Av qeeg thaj tsam: Deformation muaj peev xwm tiv thaiv nkig tawg, xws li sab hnub poob -East Gas Pipeline III project.
