Vim li cas Stainless Hlau Yog "Stainless": Core Mechanism ntawm Chromium Passive Film
Dab tsi txawv stainless hlau los ntawm cov pa roj carbon zoo tib yam yog nws cov ntsiab lus chromium tsawg kawg yog 10.5%. Chromium spontaneously reacts nrog oxygen nyob rau hauv cov huab cua los ua ib tug ntom, nruam chromium - nplua nuj passive oxide zaj duab xis ntawm nanometer scale. Qhov no ultra-thin barrier blocks noo noo, oxygen thiab corrosive media, thiab nta nws tus kheej- kho muaj peev xwm: me me nto khawb yuav sai sai regrow cov tiv thaiv chromium oxide txheej nyob rau hauv aerobic tej yam kev mob, xa mus ntev - xeb kuj.
Chromium ib leeg tsuas yog muab kev tiv thaiv yooj yim los tiv thaiv -corrosion kev ua tau zoo. Los ntawm alloying nrog npib tsib xee, molybdenum, nitrogen, titanium thiab lwm yam ntsiab lus, kev lag luam tau tsim plaub lub ntsiab metallographic stainless hlau tshuab ua kom haum rau ntau yam kev pabcuam.
Kev faib tawm, Cov Khoom Siv thiab Daim Ntawv Thov Scenarios ntawm Plaub Qhov Tseem Ceeb Stainless Steel Systems
1. Austenitic Stainless Steels (300 Series: 304, 316L, 321)
Nickel yog ntxiv rau stabilize lub austenitic microstructure. Cov qib no tsis yog -sib nqus, muaj qhov zoo tshaj plaws ductility thiab superior bendability & weldability, nrog rau qhov zoo tshaj plaws corrosion kuj.
304 (18Cr-8Ni): Cov hom phiaj dav dav rau kev siv pej xeem;
316L: Alloyed nrog 2% - 3% molybdenum rau kev txhim kho chloride ion corrosion, haum rau thaj chaw ntug dej hiav txwv, tshuaj ua haujlwm thiab dej hiav txwv;
321: Titanium-stabilized qib nrog siab -kub tsis kam thiab kev tiv thaiv rau intergranular corrosion, siv rau siab - kub pipelines thiab boilers.
2. Ferritic Stainless Steels (430, 409L; Nickel{3}}Dawb 400 Series)
Nickel- pub dawb nrog cov nqi tsim khoom qis dua, tsis muaj zog hlau nplaum thiab muaj cov thermal conductivity zoo heev, tab sis qhov nruab nrab weldability. Dav siv nyob rau hauv vaj huam sib luag khoom vaj khoom tsev, chav ua noj & chav dej kho kom zoo nkauj thiab automotive tso tshuab; tus nqi -kev xaiv zoo rau qhov chaw qhuav hauv av.
3. Martensitic Stainless hlau (410, 420)
Cov pa roj carbon ntau thiab cov ntsiab lus tsis tshua muaj chromium pab ua kom tawv tawv ntawm quenching, xa cov hardness thiab sharpness ntawm tus nqi tsis muaj zog xeb. Kev siv thawj zaug suav nrog cov cuab yeej txiav, li qub, cov kabmob thiab cov hniav phais.
4. Duplex Stainless Steels (2205, 2507)
Dual{0}}phase microstructure muaj xws li austenite thiab ferrite. Lawv lub zog tensile ob npaug ntawm 304 stainless hlau, nrog kev lag luam - ua rau pitting corrosion thiab kev ntxhov siab corrosion tawg. Raws li high-kawg tshwj xeeb stainless hlau, lawv ua haujlwm siab heev- corrosion ua hauj lwm tej yam kev mob xws li tob- hiav txwv chaw, muaj zog acid cov txheej txheem thiab seawater desalination tej yaam num.
Kev nthuav qhia ntawm Kev Lag Luam Tsis Txaus Siab
"Tsis yog-cov hlau tsis sib nqus hlau sib npaug sib npaug zoo": Qib 430 ferritic stainless hlau yog hlau nplaum, thaum txias- ua haujlwm 304 kuj tsim cov hlau nplaum me ntsis. Magnetism tsis tuaj yeem siv los txiav txim cov khoom zoo.
"Stainless steel yeej tsis xeb": Cov tshuaj ntsev hnyav hnyav, cov kua qaub muaj zog lossis kev tso dej ntev ntev tuaj yeem rhuav tshem cov zaj duab xis passive, ua rau pitting corrosion thiab xeb stains. Cov qib khoom tsim nyog yuav tsum raug xaiv raws li qhov chaw pabcuam.
