1. Dab tsi yog qhov txawv ntawm ASTM A335 Qib P11 thiab P22 welded kav nyob rau hauv cov ntsiab lus ntawm cov ntsiab lus alloy thiab daim ntawv thov kub ntau yam?Teb: Qhov sib txawv tseem ceeb ntawm ASTM A335 Qib P11 thiab P22 welded kav nyob rau hauv lawv cov ntsiab lus alloy thiab daim ntawv thov kub ntau. P11 yog qis Cr-Mo alloy steel nrog Cr: 1.00-1.50% thiab Mo: 0.45-0.65%, thaum P22 muaj Cr thiab Mo cov ntsiab lus siab dua (Cr: 2.10-2.90%, Mo: 0.87{22%). Vim yog cov ntsiab lus ntawm cov hlau ntau dua, P22 muaj qhov zoo dua siab dua - qhov kub thiab txias, kev ua haujlwm tsis zoo, thiab corrosion tsis kam tshaj P11. Daim ntawv thov kub ntau ntawm P11 yog mus txog 550 degree, thiab nws yog tsuas yog siv nyob rau hauv nruab nrab-kub, nruab nrab-siab boiler pipelines thiab petrochemical khoom. P22 tuaj yeem siv rau ntawm qhov kub txog li 600 degree, thiab nws yog qhov tsim nyog rau kev kub siab, siab kub boiler systems (xws li superheaters, reheaters) thiab petrochemical pipelines uas yuav tsum tau muaj kev nkag siab dua.
2. Cov ntsiab lus molybdenum cuam tshuam li cas rau kev nkag siab ntawm ASTM A335 Qib P92 welded kav, thiab lawv cov xwm txheej zoo li cas?Teb: ASTM A335 Qib P92 welded kav yog siab Cr-Mo-V-Nb alloy steel (Cr: 8.50-9.50%, Mo: 0.85-1.05%, V: 0.15-0. 0.04-0.09%), thiab molybdenum yog lub hauv paus tseem ceeb uas cuam tshuam rau lawv cov creep resistance. Molybdenum tuaj yeem tsim cov kev daws teeb meem hauv cov hlau, txhim kho cov qauv ntawm cov nplej, thiab tiv thaiv kev txav mus los ntawm qhov kub thiab txias, yog li txhim kho cov yeeb nkab lub zog creep thiab creep rupture lub neej. Qhov siab dua cov ntsiab lus molybdenum (nyob rau hauv tus txheej txheem ntau), qhov zoo dua qhov creep kuj. Cov xwm txheej ntawm daim ntawv thov ntawm P92 welded kav yog qhov kub thiab txias, cov khoom siv hluav taws xob siab, xws li ultra-supercritical (USC) thiab siab heev ultra-supercritical (AUSC) boiler lub ntsiab chav kav, reheater pipelines, thiab header kav, qhov chaw ua hauj lwm kub yog nyob nruab nrab ntawm 600-650℃thiab lub siab yog siab tshaj.
3. Dab tsi yog qhov yuav tsum tau ua kom zoo rau lub vuam seam ntawm GB/T 6479-2018 20G welded kav siv nyob rau hauv boiler dej phab ntsa, thiab yuav ua li cas kom vuam zoo?Teb: GB/T 6479-2018 20G welded kav yog carbon steel kav siv nyob rau hauv boiler dej phab ntsa, thiab lawv cov weld seam yuav tsum nruj me ntsis: 1) Tsis muaj tawg, tsis tiav fusion, tsis tiav kev nkag mus, los yog slag inclusion; Weld seam nto yuav tsum du, tsis muaj porosity los yog undercut . 2) Weld seam lub zog yuav tsum tsis txhob qis dua lub hauv paus hlau lub zog (tensile lub zog siab tshaj los yog sib npaug zos rau 410 MPa, yield zog ntau dua los yog sib npaug zos rau 245 MPa). 3) Weld seam yuav tsum muaj zoo toughness ntawm lub boiling cua sov (lub voj voog txias). Txhawm rau ua kom cov vuam zoo: 1) Siv cov khoom siv vuam sib txuam nrog cov hlau hauv paus (xws li E4303, E4315 electrodes). 2) Preheat cov yeeb nkab ua ntej vuam (preheating kub 80-150 degree) kom txo tau qhov mob khaub thuas tawg . 3) Tswj vuam tsis sib xws (tam sim no){100}{101} kom ruaj khov, voltage Kev kho cua sov tom qab vuam (tempering ntawm 600-650 degree) txhawm rau tshem tawm cov kev ntxhov siab nyob hauv qhov seem. 5) Ua kev soj ntsuam nruj, suav nrog kev tshuaj xyuas qhov muag, UT / RT kev sim, thiab kev ntsuas cov cuab yeej cuab tam (tensile, cuam tshuam kev ntsuam xyuas).
4. Dab tsi yog qhov kev txwv ntawm ASTM A335 Qib P5 welded kav, thiab nyob rau hauv qhov siab - qhov kub thiab txias tsis haum?Teb: ASTM A335 Qib P5 welded kav yog Cr-Mo alloy steel (Cr: 4.00-6.00%, Mo: 0.45-0.65%) nrog zoo siab - kub lub zog thiab corrosion kuj, tab sis lawv muaj qee yam kev txwv kev siv. Lawv qhov siab tshaj plaws kev khiav hauj lwm kub yog 550 degree, yog li lawv tsis haum rau siab - qhov kub thiab txias ib puag ncig siab tshaj 550 degree, xws li ultra-supercritical boiler pipelines (kev khiav hauj lwm kub siab tshaj los yog sib npaug rau 600 degree), vim hais tias lawv creep kuj thiab high-temperature zog yuav txo qis, ua rau cov kav dej deformation los yog rupture. Tsis tas li ntawd, P5 welded kav dej muaj qhov tsis zoo rau cov sulfur corrosion, yog li lawv yuav tsum tau zam nyob rau hauv ib puag ncig uas muaj cov ntsiab lus sulfur (xws li cov nroj tsuag petrochemical nrog cov sulfur crude roj ua), vim cov sulfur yuav hnov mob nrog chromium thiab molybdenum los ua sulfides, txo cov yeeb nkab corrosion kuj thiab kev pab lub neej.
5. Cov tshuaj muaj pes tsawg leeg thiab kev ua tau zoo ntawm API 5L X80 welded kav yog dab tsi, thiab vim li cas lawv thiaj siv dav hauv - cov roj thiab roj kav ntev?Teb: API 5L X80 welded kav yog siab -lub zog qis- alloy (HSLA) steel kav nrog cov tshuaj lom neeg hauv qab no: carbon (C: 0.14% max), manganese (Mn: 1.80% max), chromium (Cr: 0.50% max), molybdenum (% 0.30: Molybdenum: Molybdenum: 0.50%) 0.06% max), vanadium (V: 0.06% max), thiab titanium (Ti: 0.02% max). Lawv cov yam ntxwv ua tau zoo yog: lub zog siab (tsawg kawg yield zog 551 MPa, tensile zog 620-750 MPa), zoo toughness (lub zog cuam tshuam loj dua los yog sib npaug rau 40 J ntawm -20 degree), weldability zoo heev, thiab zoo corrosion kuj. Lawv tau dav siv nyob rau hauv cov kav dej ntev thiab cov roj av vim: 1) Lub zog siab tso cai rau cov phab ntsa ntawm cov yeeb nkab nyias nyias nyob rau hauv tib lub siab, txo cov khoom siv thiab cov nqi tsheb thauj mus los . 2) Zoo toughness thiab weldability kom ntseeg tau tias lub raj xa dej muaj kev ncaj ncees thiab kev ntseeg siab, txawm tias nyob rau hauv ib puag ncig hnyav (xws li cov cheeb tsam txias, av qeeg thaj tsam) . 3 corosion resistance) {20} pipeline kev pab cuam lub neej, txo cov nqi tu.
