1. Paub meej Chemical Composition Range ntawm Incoloy 925 (UNS N08925)
2. Lub luag haujlwm ntawm cov ntsiab lus tseem ceeb (Mo, Cu, Ti, Al) thiab lawv qhov cuam tshuam rau Alloy Properties
(1) Molybdenum
Lub luag haujlwm tseem ceeb: Thawj qhov kev tiv thaiv corrosion ua kom zoo dua qub thiab cov khoom siv - kev daws teeb meem.
Cov khoom cuam tshuam:
Qhov tseem ceeb txhim khu kev tiv thaiv raupitting, crevice corrosion, thiab kev nyuaj siab corrosion cracking (SCC)hauv kev tawm tsam hnyav (piv txwv li, chloride- muaj cov tshuaj, sulfuric acid, phosphoric acid). Mo forms a dense passive film (MoO₃) on the alloy surface, preventing localized corrosion.
Txhim kho lub zog txhua yam ntawm ob chav tsev thiab qhov kub siab los ntawm cov khoom siv- kev daws teeb meem ntxiv zog ( cuam tshuam rau cov iav siv lead ua, ua rau muaj kev tiv thaiv rau kev txav mus los).
Txhim kho kev hnav tsis kam thiab qaug zog, ua rau cov alloy haum rau siab - kev pabcuam kev ntxhov siab.
(2) Copper (Cu)
Lub luag haujlwm tseem ceeb: Corrosion inhibitor rau txo qhov chaw ib puag ncig thiab pab lub zog hloov kho.
Cov khoom cuam tshuam:
Tshwj xeeb hauv kev tawm tsamtxo cov kua qaub(piv txwv li, dilute sulfuric acid, hydrochloric acid, acetic acid) los ntawm kev tsim cov tshuaj tiv thaiv Cu- nplua nuj zaj duab xis uas inhibits anodic dissolution.
Synergizes nrog Mo los txhim kho corrosion kuj nyob rau hauv sib xyaw acid systems (xws li, acidified brines, industrial wastewaters).
Me ntsis txhim kho ductility thiab toughness, ntsuas lub alloy lub zog thiab formability.
(3) Titanium (Ti)
Lub luag haujlwm tseem ceeb: Precipitation hardening agent thiab carbide stabilizer.
Cov khoom cuam tshuam:
Cov ntaub ntawv intermetallic precipitates (piv txwv li, Ni₃Ti, TiC) thaum kho cua sov (kev daws teeb meem annealing + aging), uas ua rau kom cov hlau ntau ntxiv.tensile zog, tawm los lub zog, thiab hardness(Lub zog tawm los ntau dua lossis sib npaug ntawm 690 MPa tom qab kev laus).
Stabilizes carbon los ntawm kev tsim TiC, tiv thaiv kev tsim ntawm Cr₂₃C₆ ntawm grain ciam teb (tsis txhob chromium depletion thiab intergranular corrosion).
Txhim kho creep tsis kam ntawm qhov kub siab (txog 550 degree) los ntawm pinning lis ciam thiab dislocations.
(4) Aluminium (Al)
Lub luag haujlwm tseem ceeb: Co- nag lossis daus hardening tus neeg saib xyuas thiab oxidation kuj pab.
Cov khoom cuam tshuam:
Ua haujlwm synergistically nrog Ti los tsim kom zoo, uniformly faib Ni₃(Al, Ti) precipitates ('theem) thaum laus, ntxiv dag zog rau cov alloy.siab -qhov kub thiab txias tsis kam(tseem ceeb rau kev siv xws li cov cuab yeej downhole thiab cov khoom siv roj turbine).
Txhim kho siab -kub oxidation tsis kam los ntawm kev tsim ib txheej nyias Al₂O₃ rau ntawm qhov chaw, ua tiav cov Cr- nplua nuj oxide zaj duab xis.
Tswj qhov loj thiab kev faib tawm ntawm precipitates kom tsis txhob dhau brittleness, tswj cov alloy lub toughness thiab weldability.
