1. Q: Qhov txawv ntawm ERW, LSAW, thiab SSAW steel kav yog dab tsi?
A:Lawv txawv ntawm lawv txoj kev tsim thiab vuam.ERW (Electric Resistance Welded)cov kav dej yog tsim los ntawm ib lub tiaj tiaj thiab welded longitudinally los ntawm siab - zaus tam sim no, feem ntau yog siv rau me me mus rau nruab nrab diameters -6.LSAW (Longitudinal Submerged Arc Welded)Cov kav dej yog tsim los ntawm ib lub phaj hlau (UOE lossis JCOE txheej txheem) thiab welded longitudinally nrog submerged arc vuam, zoo tagnrho rau cov kab loj loj thiab cov phab ntsa hnyav.SSAW (kauv submerged Arc Welded)cov kav dej yog tsim los ntawm kev muab kauv ua ib qho kub - dov coil thiab vuam ob sab hauv thiab sab nraud, haum rau cov kab loj loj tab sis nrog qhov ntev dua weld seam -6.
2. Q: Qib "X" hauv API 5L pipeline steel txhais li cas?
A:Tus "X" yog ua raws li tus lej uas sawv cev rauyam tsawg kawg nkaus yield zoghauv ksi (kilo-pound per square inch). Piv txwv li, X42 muaj qhov tsawg kawg nkaus yield zog ntawm 42 ksi (kwv yees . 290 MPa), thaum X80 muaj qhov tsawg kawg nkaus yield zog ntawm 80 ksi (approx . 550 MPa). Cov qib siab dua li X80 muab lub zog ntau dua, tso cai rau cov phab ntsa nyias thiab ua haujlwm siab dua -3-9.
3. Q: Dab tsi yog qhov nyuaj thaum vuam siab -lub zog qis- alloy (HSLA) steels zoo li X80?
A:Thawj qhov kev sib tw yog zamhydrogen{0}}induced cracking (HIC)nyob rau hauv lub vuam hlau thiab tshav kub- cuam tshuam cheeb tsam (HAZ). Raws li steel zog nce, nws susceptibility rau hydrogen embrittlement nce. Qhov no yuav tsum muaj kev tswj hwm nruj ntawm cov qib hydrogen hauv cov khoom siv, kev ua kom zoo preheat thiab interpass kub, thiab cov cua kub tsim nyog los tiv thaiv qhov txias txias -9.
4. Q: Vim li cas 316L stainless hlau feem ntau nyiam tshaj 304L rau welded kav hauv qhov chaw corrosive?
A:316L muajmolybdenum (2-3%), uas significantly txhim khu nws kuj muspitting thiab crevice corrosion, tshwj xeeb tshaj yog nyob rau hauv chloride- thaj chaw nplua nuj xws li thaj chaw ntug dej hiav txwv lossis kev ua tshuaj lom neeg. Ob leeg yog qib "L" (tsawg carbon,<0.03% C), which minimizes carbide precipitation during welding and maintains corrosion resistance in the as-welded condition -7.
5. Q: Duplex thiab Super Duplex stainless hlau yog dab tsi, thiab vim li cas lawv siv?
A:Lawv muaj ib tug sib xyaw microstructure ntawm austenite thiab ferrite, muab roughlymuab ob npaug rau lub zog tawm los ntawm cov qib qib austeniticzoo li 304 lossis 316. Lawv kuj muab kev tiv thaiv zoo heev rau kev ntxhov siab corrosion cracking (SCC) thiab pitting. Cov qhab nia muaj xws li UNS S31803 (2205) thiab UNS S32750 (2507), siv rau hauv kev xav tau cov roj av sab nrauv & roj thiab tshuaj siv roj tanker -7.
