Ma alloy achikhalidwe amagwira ntchito yodziwika bwino popanga zitsulo, kaya ndi chitsulo chosapanga dzimbiri chomwe chimagwiritsidwa ntchito muzipangizo zachipatala kapena nsomba, mibadwo iliyonse ya zitsulo zogwira ntchito bwino zomwe zapangidwa m'zaka zingapo zapitazi zamakampani opanga magalimoto, kapena zitsulo monga aluminiyamu ndi titaniyamu, zomwe zimakhala ndi mphamvu yolemera kwambiri komanso kukana dzimbiri kwambiri zimapangitsa kuti zikhale zoyenera kugwiritsidwa ntchito m'mafakitale opanga ndege, mafuta oyenga ndi mankhwala.
Izi zikugwiranso ntchito pa zitsulo zina za kaboni, makamaka zitsulo zokhala ndi kaboni ndi manganese. Kutengera kuchuluka kwa zinthu zophatikizira, zina mwa izo ndizoyenera kupangama flange, zolumikizirandimapaipim'makampani opanga mankhwala ndi mafuta. Zonsezi zili ndi chinthu chimodzi chofanana: zipangizo zomwe zimagwiritsidwa ntchito pa ntchitozi ziyenera kukhala zofewa mokwanira kuti zisawonongeke ndi kusweka kwa brittle fracture ndi stress corrosion cracking (SCC).
Mabungwe oyendera miyezo monga American Society of Manufacturing Engineers (ASME) ndi ASTM Intl. (yomwe kale inkadziwika kuti American Society for Testing and Materials) amapereka malangizo pankhaniyi. Ma code awiri ofanana amakampani-Boiler ya ASMEndi Pressure Vessel (BPVD) Gawo VIII, Gawo 1, ndi ASME B31.3, Process Piping - imayang'ana chitsulo cha kaboni (chilichonse chokhala ndi 0.29% mpaka 0.54% kaboni ndi 0.60% mpaka 1.65% manganese, zinthu zokhala ndi chitsulo). Yosinthasintha mokwanira kuti igwiritsidwe ntchito m'malo otentha, madera ozizira komanso kutentha kotsika mpaka madigiri -20 Fahrenheit. Komabe, zovuta zaposachedwa pa kutentha kwa mlengalenga zapangitsa kuti pakhale kufufuza bwino kuchuluka ndi kuchuluka kwa zinthu zosiyanasiyana zomwe zimagwiritsidwa ntchito popanga ma flanges, ma fittings ndi mapaipi achitsulo a api.
Mpaka posachedwapa, ASME kapena ASTM sizinafunikire kuyesa kukhudzidwa kuti zitsimikizire kusinthasintha kwa zinthu zambiri zachitsulo cha kaboni zomwe zimagwiritsidwa ntchito kutentha mpaka madigiri -20 Fahrenheit. Chisankho chochotsa zinthu zina chimadalira mbiri yakale ya zinthuzo. Mwachitsanzo, kutentha kochepa kwa kapangidwe ka chitsulo (MDMT) ndi madigiri -20 Fahrenheit, sichimayesedwa kukhudzidwa chifukwa cha ntchito yake yachikhalidwe pakugwiritsa ntchito zinthuzi.
Nthawi yotumizira: Epulo-19-2023