Dab tsi yog oxidation tsis kam ntawm Astm A335 p5 steel yeeb nkab ntawm qhov kub thiab txias?
Vim tias p5 steel yeeb muaj 4-6% chromium, nws tsim cov yeeb yaj kiab ntom ntom ntom ntom ntag hauv qab 650℃kev tiv thaiv ntxiv oxidation. Thaum raug rau qhov kub ntev ntev, cov yeeb yaj kiab oxide yuav ib nrab ntawm cov nplaim taws, tab sis nws muaj lub peev xwm tseem ceeb tshaj plaws. Qhov siab tshaj 650 degree, oxidation tus nqi accelerates, tsim nyog siv lub thermal teeb meem txheej. Nws oxidation tsis kam yog zoo dua rau cov hlau steel tab sis qis dua rau cov hlau tsis muaj zog (xws li 304). Kev soj ntsuam ib txwm rau cov phab ntsa tuab txo tau yog qhov tsim nyog hauv cov ntawv thov kev siv.
Dab tsi yog qhov tsis kam ntawm Astm A335 p5 steel yeeb nkab los sulfidation corrosion?
Chromium imparts excellent resistance to sulfidation corrosion in P5 steel pipe, especially in sulfur-containing petroleum or chemical media. However, hydrogen sulfide (H₂S) corrosion may still occur in high-temperature (>400 degree) thiab siab-}}}} sulfur ib puag ncig, ua rau embrittlement lossis pitting. Nyob rau hauv cov rooj plaub no, nws yog qhov tsim nyog los txo cov sulfur cov ntsiab lus ntawm nruab nrab lossis lub luag haujlwm aluminizing kev tiv thaiv. Piv rau p9 steel yeeb (8-10% chromium cov ntsiab lus), nws cov tub faj tsis muaj zog yog tsis muaj zog me ntsis, tab sis tus nqi qis dua.
P5 P5 Cov Yeeb Nkab Ua li cas hauv cov acidic ib puag ncig (xws li HCL lossis H₂so₄)?
P5 Steel Yeeb Nkab Ua tau zoo nyob rau hauv qis {{1} {{{-} Cov ntsuas kub thiab txias acidic ib puag ncig. Txawm li cas los xij, siab {-}} {- kub acids tuaj yeem ua rau muaj mob hnyav. Hydrochloric acid (HCl) tshwj xeeb yog kev puas tsuaj thiab tuaj yeem ua rau pitting corrosion thiab kev nyuaj siab corrosion tawg. Nyob rau hauv cov xwm txheej zoo li no, nws raug nquahu kom hloov mus rau haastelloy lossis yas- txoj kab ua yeeb nkab. Yog tias HCL yog unavoidable, corrosion inhibitors yuav tsum tau ntxiv thiab ph ntawm nruab nrab yuav tsum nruj me ntsis tswj. Tsis tu ncua Eddy kev sim tam sim no tuaj yeem ntes cov tshuaj tsis taus xeb thaum ntxov.
Yog astm A335 p5 steel yeeb nkab raug rau intergranular corrosion?
Nyob rau hauv qhov rhiab kub ntau ntawm 450 - 850℃(xws li cov cua sov {5 5}} Txoj kev cuam tshuam nrog cov khoom sib txuam ntawm cov ciaj ciam av, ua rau muaj kev cuam tshuam nrog corrosion. Qhov teeb meem no tuaj yeem ua kom muaj kev cuam tshuam los ntawm txo cov ntsiab lus carbon (tsawg dua los yog sib npaug rau 0.15%) thiab ntxiv rau cov khoom ruaj khov (xws li ti / nb). Tom qab kev kho vaj hauv weld (piv txwv li, quenching) kuj tuaj yeem tshem tawm cov nag los nag. Thaum siv nyob rau hauv kev corrosive ib puag ncig, intergranular corrosion kev sim (piv txwv li, Astm A262 kev coj ua kev pom zoo.
Yuav ua li cas tuaj yeem kho cov kev kho sab txhim kho cov corrosion tsis kam ntawm p5 steel yeeb nkab?
Cov hau kev suav nrog kev tua cov panening (kom nce qhov chaw compressive excertive), alstows tiv thaiv txheej), lossis ceramic txheej txheem (piv txwv li, zro₂). Electrolytic muaj peev xwm ua tau nyob rau sab hauv kom txo txoj kev pheej hmoo ntawm hauv {} acead duas corrosion. Rau cov av marine ib puag ncig, kev txi anode lossis qhuas cov tshuaj harodic tam sim no yuav tsum muaj. Thaum xaiv cov txheej txheem kho, xav txog tus nqi, kev ua haujlwm kub, thiab cov yam ntxwv tshaj tawm.
