Siab nickel alloys
Nickel yog qhov thib tsib feem ntau hauv ntiaj teb, tab sis kom txog rau thaum lub xyoo pua xeem nws tau siv tau raug txwv vim qhov nyuaj ntawm tsuas thiab ua kom zoo. Kev loj hlob ntawm cov hluav taws kub yog ib qho tseem ceeb rau kev txhim kho cov neeg npib tsib xee-alloys alloys uas muaj peev xwm tswj hwm siab ntawm lub zog siab ntawm kev kub siab.
Nickel muaj lub ntsiab lus melting ntawm 1453 degrees Celsius, uas yog ntau dua li tus tooj liab xws li tungsten (3400 degrees Celsius). Txawm li cas los xij, kev ua tau kub yog tsis tsuas yog hais txog lub ntsiab lus melting ntawm cov hlau, lwm yam hlau (1400 degrees Celsius) yuav siv tau ntau dav siv. Lwm cov cuab yeej ntawm npib tsib xee thiab nickel alloys yog lawv lub peev xwm los tsim cov roj oxide thiab ruaj khov, uas tiv thaiv kom lawv ua haujlwm ntawm kev kub siab. Cov roj oxide no tuaj yeem muaj ntau microns tuab, nyob ntawm qhov kub thiab ib puag ncig cov hlau raug. Nickel alloys kuj tseem tiv taus carburization, uas yog muaj cov pa roj carburization, xws li thaum tawg ua haujlwm hauv ntau yam kev ua haujlwm lossis ua haujlwm ntxiv.
Ntxiv dag zog rau cov txheej txheem
Nyob ntawm qhov tshwj xeeb alloy, nws qhov siab-lub zog yog tswj tau los ntawm cov tshuaj muaj zog zog lossis dej nag lossis daus ntau zog. Lub tshuab ntawm cov khoom siv daws teeb meem yog cov khoom siv dag zog yog qhov ntxiv ntawm cov atoms ntawm cov ntsiab lus rau lub npib tsib xee lub ntsej muag. Qhov kev sib tw no ntawm cov qauv siv lead ua ua rau muaj kev cuam tshuam ntau dua los ntawm kev qeeb lossis tiv thaiv kev txav ntawm "kev tsis sib haum xeeb." Cov ntsiab xws li Molybdenum tau ntxiv rau inconel 625 (Alloy 625, 2.4856) kom nce lub zog.
Hauv nag lossis daus muaj zog, me me ntawm niobium, titanium, thiab txhuas ua ke nrog npib tsib xee los tsim intermetallic precipitates. Cov precipitates yog tsim thaum lub sijhawm kev kho kom sov kawg, tseem hu ua kev laus. Cov precipitates kuj qeeb kev txav ntawm kev tsis sib haum xeeb hauv cov qauv crystal, uas ua rau muaj zog thiab tawv. Thaum muaj qhov kub siab dua, cov tshuab no tseem txo qis qhov ntxim nyiam ntawm creep, uas yog siv tau zoo siv hauv kev siv hluav taws xob hauv Aerospace. Nickel alloys uas siv cov nag lossis zes 725, tsis ua tiav N07715 (Alloy 725 (Alloy K {}}}, tsis muaj N05500, 2.4375).
Alloys xws li Inconel 718 thiab Inconel 625 khaws cov khoom siv ntau dua li ntawm 650 degrees Celstheit), tab sis tuaj yeem xaiv tau txog 1000 degrees Celsiusitheit).
Vim tias nickel alloys yooj yim nrog ntau cov hlau, nws tuaj yeem txhim kho corrosion tsis kam thiab lwm yam khoom siv lub cev ntxiv rau lub zog. Chromium thiab molybdenum feem ntau ntxiv rau txhim kho corrosion thiab oxidation tsis kam, nrog molybdenum kev txiav txim siab los txhim kho pitting. Tooj liab tseem siv nyob rau hauv incoloy 825 alloy kom txhim kho nws txoj kev tiv thaiv kom txo cov kua qaub xws li sulfuric, phosphoric, thiab hydrochloric acids.
