X60 loj- txoj kab uas hla steel yeeb nkab yog siab - lub zog kav hlau yeeb nkab nrog lub zog ntawm 414-517MPa. Nws cov ntsiab lus carbon yog tswj tau nyob rau hauv qis- carbon ntau ntawm qis dua 0.12%, kom ntseeg tau zoo weldability thiab qis- kub toughness. Qhov kev faib ua feem ntawm microalloying cov ntsiab lus xws li manganese, niobium, thiab vanadium muab qhov tsim nyog zoo - cov nplej ntxiv dag zog thiab nag lossis daus muaj zog. Piv nrog X52 loj- txoj kab uas hla welded yeeb nkab, X60 loj- txoj kab uas hla welded steel yeeb nkab muaj qib siab dua; piv nrog X65 loj-inch welded steel yeeb nkab, nws weldability thiab toughness yog superior.
Chemical Composition Design thiab Microstructure yam ntxwv ntawm X60 Loj -Diameter Welded Steel Pipe
Cov tshuaj lom neeg muaj pes tsawg leeg ntawm X60 loj- txoj kab uas hla welded steel yeeb nkab yog ua tib zoo tsim, nrog ntau yam raws li hauv qab no: Carbon (C) Tsawg dua los yog sib npaug rau 0.12%, Silicon (Si) Tsawg dua los yog sib npaug rau 0.45%, Manganese (Mn) 1.25% -1.60%, Phosphorus (P) Less dua 0.0 los yog sib npaug 0.015%, Niobium (Nb) 0.02%-0.05%, Vanadium (V) 0.04%-0.10%, Titanium (Ti) 0.010%-0.025%, Aluminium (Alt) Ntau dua lossis sib npaug li 0.020%, Nitrogen (N) Tsawg dua 0.01%. Qhov tseeb muaj pes tsawg leeg no yog lub hauv paus rau cov khoom siv ruaj khov.
Qhov sib txawv alloying ntsiab ua lub luag haujlwm sib koom ua ke hauv X60 loj- txoj kab uas hla welded yeeb nkab. Cov ntsiab lus carbon tsawg yog qhov tseem ceeb rau kev ua kom muaj kev sib txuas thiab qis -kub toughness. Manganese txhim kho lub zog thiab txo qis theem ntawm kev hloov pauv kub los ntawm kev daws teeb meem ntxiv dag zog. Microalloying cov ntsiab lus xws li niobium, vanadium, thiab titanium txhim khu lub zog los ntawm cov nplej ua kom zoo thiab nag lossis daus. Aluminium ua raws li deoxidizer, tsim AlN hais thiab inhibiting austenite grain loj hlob. Kev tswj hwm nruj ntawm cov ntsiab lus ntawm cov sulfur kom ntseeg tau cov khoom purity siab, uas yog qhov tseem ceeb tshwj xeeb rau kev tiv thaiv HIC (hydrogen-induced cracking).
Tus qauv microstructure ntawm X60 loj- txoj kab uas hla welded yeeb nkab yog ib qho zoo ferrite-pearlite multiphase qauv. Tom qab tswj tau dov thiab txias txheej txheem, ferrite grain loj feem ntau ncav cuag ASTM qib 9 lossis siab dua, thiab cov ntsiab lus pearlite yog kwv yees li 15% -25%. Transmission electron microscopy nthuav tawm nanoscale (Nb, V) (C, N) precipitates faib hauv cov hlau, nrog qhov loj ntawm kwv yees li 10-30 nm. Cov precipitates no yog qhov tseem ceeb ntawm cov khoom siv lub zog siab. Electron backscatter diffraction (EBSD) tsom xam qhia tau hais tias cov khoom muaj ib tug zoo li grain orientation tis thiab tsis pom tseeb kev ntxhib los mos.
Advanced microscopic tsom xam cov tswv yim tau nthuav tawm cov yam ntxwv zoo ntawm X60 loj - txoj kab uas hla welded yeeb nkab. Peb -dimensional atomic sojntsuam microanalysis (APT) tau lees paub tias cov microalloying cov ntsiab lus tau sib npaug ntawm cov matrix, ua rau siab -density nano- theem precipitate. High-kev daws teeb meem kis tau tus mob electron microscopy (HRTEM) qhia tias Nb(C,N) precipitate theem tswj kev sib raug zoo nrog matrix. Qhov tshwj xeeb microstructure no ua rau X60 loj- txoj kab uas hla welded yeeb nkab kom muaj lub zog txaus thaum muaj qhov ua tau zoo heev, tshwj xeeb tshaj yog qis - qhov kub thiab txias tsis kam.
API 5L X60 loj txoj kab uas hla welded yeeb nkab Hoobkas
