1.Dab tsi yog lub tswv yim tseem ceeb ntawm cov tshuaj muaj pes tsawg leeg rau tus nqi - ua tau zoo ERW- qib hlau zoo li API 5L X65?
Ib qho qis- carbon, microalloyed tsim yog ntau. Piv txwv li, tus nqi - zoo X65 muaj pes tsawg leeg rau nyias -slab casting yuav siv tau:C: 0.05%, Mn: ~ 1.5%, nrog micro- ntxiv ntawm Nb (~ 0.045%) thiab Ti (~ 0.02%)-5. Qhov no lean chemistry, ua tiav los ntawm kev tswj dov thiab txias, ua tiav lub zog siab los ntawm cov nplej refinement thiab nag lossis daus hardening, txo nqi alloying ntsiab.
2.Yuav ua li cas lub zog tsis sib haum xeeb ntawm ERW yeeb nkab lub cev thiab nws girth weld cuam tshuam tus cwj pwm tsis ua haujlwm?
Rau qib siab - cov kav dej (xws li X80), girth welds feem ntau tsim los ua"muaj zog sib tw"(weld hlau zog Ntau dua los yog sib npaug rau cov yeeb nkab zog)-6. Txawm li cas los xij, yog tias "tsis muaj kev sib tw" tshwm sim los yog muaj qhov tsis xws luag, tsis ua hauj lwm nyob rau hauv kev khoov loads yuav pib nyob rau hauv lub vuam los yog nws HAZ. Kev tshawb fawb qhia tau hais tias tsis ua hauj lwm feem ntau pib ntawm lub hauv paus los yog nyob rau hauv lub toughness - cheeb tsam tsis zoo uas cov weld fusion kab raws li cov ntxhib-grained HAZ-6.
3.Dab tsi yog lub hauv paus txheej txheem rau kev tawg hauv ERW cov kav xa mus rau ze rau - nruab nrab pH av ib puag ncig?
Qhov tseem ceeb mechanism yognyob ze -neutral pH Stress Corrosion Cracking (SCC), tseem hu ua "low-pH SCC"-4. Nws tshwm sim nyob rau hauv disbonded coatings qhov twg cathodic tiv thaiv yog shielded. Lub cracking yog tsav los ntawmhydrogen embrittlement, qhov twg atomic hydrogen generated los ntawm corrosion ntawm qhov tawg ntswj diffuses rau hauv cov hlau, txhawb transgranular tawg propagation nyob rau hauv qib xws li X52 thiab X65-4.
4.Dab tsi yog "bridging effect" nyob rau hauv cov ntsiab lus ntawm welding ib tug ERW yeeb nkab mus rau ib tug yeeb nkab ntawm txawv qib los yog thickness?
Thaum asiab- zog, nyias- cov yeeb nkab phab ntsa(xws li API X80) tau koom nrog aqis- zog, tuab- cov yeeb nkab phab ntsa(xws li API X42), tus qauv tsim feem ntau tapers cov yeeb nkab tuab kawg. Cov "bridging effect" piav qhia txog yuav ua li cas cov yeeb nkab uas muaj zog dua, nruj dua, txhawb nqa cov kab sib txuas ntawm cov yeeb nkab uas tsis muaj zog, pab hloov cov load thiab muaj peev xwm hloov qhov tsis ua hauj lwm taw tes rau siab dua - cov khoom siv zog-8.
5.Dab tsi txias - ua cov kauj ruam hauv cov txheej txheem ERW txhim kho nws qhov kev sib tsoo tsis zoo nyob rau sab nraud?
Tom qab vuam thiab seam kev kho mob, cov yeeb nkab kis tau los ntawm ib tug series ntawmsizing roller standsqhov twg nws txias - ua rau nws txoj kab kawg-1. Qhov kev nthuav dav txias no txhim khoroundness thiab txo residual stresses, ob qho tib si uas ua rau kom cov yeeb nkab tsis kam rau buckling thiab vau nyob rau hauv sab nraud siab, qhov tseem ceeb tshaj plaws rau kev siv offshore-1.
