Cov hlau sib xyaw ua ke ua lub luag haujlwm tseem ceeb hauv kev tsim cov hlau, txawm tias nws yog cov hlau tsis xeb siv rau hauv cov khoom siv kho mob lossis cov khoom noj hiav txwv, ib qho ntawm cov tiam neeg ntawm cov hlau ua tau zoo tsim nyob rau ob peb xyoos dhau los rau kev lag luam tsheb, lossis cov hlau xws li txhuas thiab titanium. uas muaj lub zog siab rau qhov hnyav piv thiab kev tiv thaiv corrosion siab ua rau nws tsim nyog rau kev siv hauv aerospace, roj refining thiab tshuaj lom neeg kev lag luam.
Tib yam siv rau qee cov hlau carbon alloys, tshwj xeeb tshaj yog cov alloys nrog qee cov carbon thiab manganese cov ntsiab lus. Nyob ntawm seb muaj pes tsawg ntawm cov ntsiab lus alloying, qee qhov ntawm lawv zoo rau kev tsim khoom ntawmcov flanges, cov khoom sivthiabcov kav dejhauv cov chaw ua tshuaj lom neeg thiab roj av. Lawv txhua tus muaj ib yam zoo sib xws: cov ntaub ntawv siv rau hauv cov ntawv thov no yuav tsum muaj zog txaus kom tiv taus qhov tawg thiab kev ntxhov siab corrosion cracking (SCC).
Cov koom haum txheem xws li American Society of Manufacturing Engineers (ASME) thiab ASTM Intl. (yav tas los hu ua American Society for Testing and Materials) muab cov lus qhia txog qhov no. Ob lub lej kev lag luam cuam tshuam-ASME Boilerthiab Lub Taub Hau Siab (BPVD) Ntu VIII, Ntu 1, thiab ASME B31.3, Cov Kav Dej Txheej Txheem - hais txog cov hlau carbon (txhua yam uas muaj 0.29% txog 0.54% carbon thiab 0.60% txog 1.65% manganese, hlau muaj cov ntaub ntawv). yoog tau txaus rau kev siv hauv huab cua kub, thaj chaw sov thiab qhov kub qis li -20 degrees Fahrenheit. Txawm li cas los xij, qhov teeb meem tsis ntev los no ntawm qhov kub thiab txias tau ua rau muaj kev tshuaj xyuas ze dua ntawm cov nqi thiab cov feem ntawm ntau yam microalloying elements siv hauv kev tsim cov flanges, fittings thiab api hlau yeeb nkab.
Txog thaum tsis ntev los no, ASME lossis ASTM tsis tas yuav tsum tau kuaj xyuas qhov cuam tshuam kom paub meej tias cov khoom siv hlau carbon ntau npaum li cas siv rau qhov kub qis li -20 degrees Fahrenheit. Qhov kev txiav txim siab tsis suav nrog qee yam khoom yog raws li cov khoom keeb kwm ntawm cov khoom siv. Piv txwv li, thaum qhov kub tsawg kawg nkaus ntawm kev tsim hlau (MDMT) yog -20 degrees Fahrenheit, nws raug zam los ntawm kev kuaj xyuas qhov cuam tshuam vim nws lub luag haujlwm ib txwm muaj hauv cov ntawv thov no.
Lub sijhawm tshaj tawm: Plaub Hlis-19-2023