1.ERW manufacturing txheej txheem ua li cas weld seam susceptible rau Sulfide Stress Cracking (SSC) nyob rau hauv qaub kev pab cuam ib puag ncig?
Qhov siab - vuam zaus thiab txias ceev uas muaj nyob rau hauv ERW txheej txheem tuaj yeem tsim ib qho chaw nyuaj microstructure raws li qhov vuam seam thiab Kub-Teb chaws cuam tshuam (HAZ)-1. Qhov kev nyuaj siab no (yog tias siab dua ~ 248 HV) yog qhov tseem ceeb rau kev pib SSC thaum cov yeeb nkab raug rau qhov chaw ntub dej H₂S. Qhov no yog qhov kev txiav txim siab tseem ceeb rau txhua qib, suav nrog API 5L X52, X65, thiab X70 feem ntau siv hauv cov kav dej qaub-1-4.
2.Dab tsi tshwj xeeb tshaj tawm -weld kev kho cua sov yog pom zoo los xyuas kom meej ERW yeeb nkab toughness hauv qib xws li X80 thiab siab dua?
Rau siab - qib zog (X80 thiab tshaj),seam annealingyog qhov tseem ceeb. Kev tshawb fawb qhia tias annealing kub nyob rau hauv ntau yam ntawm850-970 ° F (1562-1778 ° F)yog siv los normalize lub coarse grain qauv nyob rau hauv weld cheeb tsam -9. Qhov kev kho mob no yog qhov tseem ceeb kom rov qab tau cov pob txha tawv tawv, tshwj xeeb tshaj yog rau cov kav dej uas yuav muaj kev hloov pauv siab lossis kev pabcuam kub-1-9.
3.Dab tsi yog "longitudinal joint factor (E)" rau ERW yeeb nkab hauv cov qauv tsim, thiab nws piv rau seamless yeeb nkab li cas?
Raws li US pipeline tsim cov cai (xws li, 49 CFR 192.113), ERW yeeb nkab yog muab ib tug longitudinal sib koom ua ke (E) ntawm1.00-3. Qhov no yog tib yam uas muab rau seamless thiab submerged arc welded (SAW) yeeb nkab, qhia tias niaj hnub, zoo-tswj ERW yeeb nkab yog suav hais tias muaj ib tug seam ntawm sib npaug zog rau cov yeeb nkab lub cev rau tsim lub hom phiaj.
4.Dab tsi yog hom vuam tsis zoo uas muaj nyob hauv ERW seams uas tuaj yeem ua raws li qhov chaw pib ua tsis tiav?
Cov teeb meem tshwj xeeb rau ERW daim ntawv cog lus tuaj yeem suav nrogtxias welds (tsis txaus fusion), penetrators (spots of incomplete fusion), thiab non{0}}metallic inclusions(xws li elongated Ca lossis Al oxides)-9. Thaum NDT niaj hnub tuaj yeem kuaj pom feem ntau, cov teeb meem no, ua ke nrog qhov tsis sib xws ntawm thaj chaw weld toughness, keeb kwm ua rau muaj teeb meem xws li "siab rov qab" ua tsis tiav-9.
5.Vim li cas kev tswj qhov nyuaj yog qhov tseem ceeb hauv ERW vuam ntawm qib siab - cov kav dej zoo li X65 thiab X70 rau kev pabcuam qaub?
Hardness yog qhov taw qhia ncaj qha ntawm cov ntaub ntawv qhov raug rau SSC thiab Hydrogen Induced Cracking (HIC). Cov qauv zoo li ISO 15156 thiab NACE MR0175 tswj hwm qhov siab tshaj plaws hardness hauv vuam thiab HAZ, feem ntauTsawg dua lossis sib npaug rau 248 HV10los yog 22 HRC-1. Rau cov qib xws li X65 thiab X70, ua tiav qhov no yuav tsum muaj kev tswj xyuas meej ntawm cov khoom siv hluav taws xob thiab cov seam annealing tom qab los tiv thaiv kev tsim ntawm hard martensitic microstructures.
