Taw Qhia Rau Cov Txheej Txheem Tiv Thaiv Corrosion Rau Fasteners
Apr 08, 2026
Fastenersyog cov khoom siv ntau tshaj plaws hauv cov cuab yeej siv tshuab siv rau kev sib txuas ceev, tag nrho cov no yog siv rau hauv ib puag ncig tshwj xeeb. Kev sib cuam tshuam ntev ntawm cov fasteners thiab ib puag ncig yuav ib txwm hloov lawv lub xeev thiab kev ua haujlwm, uas yog, corrosion tshwm sim, uas yog ib qho tseem ceeb ntawm cov fastener tsis ua hauj lwm. Kev txhim kho me me ntawm cov fasteners yuav cuam tshuam rau kev tshem tawm thiab rov siv tau ntawm cov xov, thaum corrosion hnyav yuav ua rau lub zog ntawm kev sib txuas ntawm cov khoom, thiab tseem ua rau tsis ua haujlwm ntawm cov khoom ua haujlwm thiab kev puas tsuaj loj. Yog li ntawd, kev tiv thaiv corrosion ntawm fasteners yeej ib txwm yog lub ntsiab lus ntawm kev txhawj xeeb loj.
Common Anti-Corrosion Technologies rau Fasteners
Kev tiv thaiv corrosion ntawm fasteners feem ntau tsim txheej txheej los tiv thaiv corrosion ntawm qhov chaw ntawm lub workpiece los ntawm qee txoj hauv kev los tiv thaiv ib puag ncig sab nraud los ntawm kev cuam tshuam cov fasteners lawv tus kheej thiab ua tiav cov nyhuv ntawm corrosion kuj. Muaj plaub yam tseem ceeb los tiv thaiv corrosion technologies rau fasteners: zaj duab xis kho tshuab, hlau plating tshuab, txheej tshuab thiab hloov cov qauv sab hauv ntawm hlau (xws li stainless hlau).
1. Zaj duab xis kho tshuab
Kev kho zaj duab xis thev naus laus zis feem ntau yog hais txog cov txheej txheem ntawm kev tsim cov tshuaj lom neeg ruaj khov (electrochemical) hloov dua siab tshiab ntawm cov hlau nto los ntawm kev siv tshuaj los yog electrochemical txoj kev. Piv txwv li, nyob rau hauv lub nroog tsheb ciav hlau tsheb, blackening / blueing kev kho mob thiab phosphating kev kho mob yog dav siv rau cov zaj duab xis kev kho mob ntawm fasteners.
1.1 Blackening thiab Blueing
Cov txheej txheem ntawm kev muab cov hlau nyob rau hauv cov tshuaj muaj zog alkaline uas muaj cov oxidants thiab kho lawv ntawm 140℃rau ib lub sijhawm los tsim cov tshuaj oxide zaj duab xis (tsuas yog tsim los ntawm Fe₃O₄) ntawm qhov chaw ntawm cov hlau yog hu ua blackening/blueing treatment.
Cov yam ntxwv ntawm kev kho blackening / blueing:
1) Zaj duab xis thickness yog 0.5-1.5 μm.
2) Lub sij hawm nruab nrab ntsev tsuag tshuaj tsuag (NSS) feem ntau tsuas yog 2 ~ 5 Hrs, thaum lub sij hawm oxide zaj duab xis tau tawg, thiab txawm ntau xeb yuav tshwm sim.
3) Tsawg hydrogen embrittlement rhiab heev, tuaj yeem siv raumuaj zog bolts.
4) Raws li ib tug fastener, nws torque-preload sib xws tsis zoo.
5) Cov xim ci thiab cov nyhuv zoo nkauj.
6) Tus nqi qis.
1.2 Kev Kho Mob Phosphating
Cov txheej txheem ntawm immersing steel qhov chaw nyob rau hauv ib tug tov uas muaj manganese, phosphoric acid, phosphate thiab lwm yam reagents los tsim ib tug dej-insoluble phosphate hloov dua siab tshiab zaj duab xis rau ntawm hlau nto yog hu ua phosphating kev kho mob. Cov yam ntxwv ntawm kev kho phosphating yog raws li nram no:
1) Cov yeeb yaj kiab tau ruaj khov nrog cov substrate (thickness 1 ~ 50 μm).
2) Lub sijhawm nruab nrab ntsev tshuaj tsuag (NSS) tuaj yeem ncav cuag 10 ~ 20 Hrs, thiab qee qhov tuaj yeem ncav cuag 72 Hrs.
3) Mechanical zog tsis zoo thiab nkig zoo nkauj.
4) Raws li lub fastener, nws torque-preload zoo sib xws.
5) Cov xim tsaus xws li lub teeb grey, thiab cov nyhuv zoo nkauj tsis zoo.
6) Tsawg hydrogen embrittlement rhiab heev, tuaj yeem siv rau cov bolts muaj zog.
7) Tus nqi qis.
2. Hlau Plating Technology
Hlau plating tshuab yog txheej txheem kho saum npoo uas feem ntau tsim cov txheej hlau nyias ntawm cov ntaub ntawv hlau los ntawm kev siv tshuab plating los muab cov khoom siv hlau nrog cov khoom zoo nkauj lossis kev tiv thaiv. Hauv tsheb ciav hlau hauv nroog, hlau plating tshuab rau fasteners feem ntau yog galvanizing, nrog rau lwm cov hlau tshwj xeeb plating (chromium plating, npib tsib xee plating, cadmium plating, nyiaj plating, thiab lwm yam).
2.1 Galvanizing
Zinc thiab hlau yog miscible, thiab lawv cov qauv electrode muaj peev xwm yog -0.76 V. Rau cov hlau substrate, zinc txheej yog anodic txheej, uas tuaj yeem tiv thaiv cov hlau substrate zoo dua. Yog li ntawd, galvanizing tshuab yog dav siv nyob rau hauv fasteners. Muaj peb txoj hauv kev galvanizing: kub-dip galvanizing, electrogalvanizing thiab mechanical galvanizing.
2.1.1 Kub-Dip Galvanizing
Kub-dip galvanizing yog hais txog cov txheej txheem ntawm immersing steel qhov chaw nyob rau hauv molten kua zinc, uas ua rau ib tug series ntawm lub cev thiab tshuaj cov tshuaj tiv thaiv nyob rau saum npoo ntawm lub workpiece los tsim ib tug hlau zinc txheej. Lub thickness ntawm kub-dip galvanizing txheej yog tuab (txog 30 ~ 60 μm), thiab nws cov corrosion kuj zoo heev. Nws yog dav siv nyob rau hauv steel qhov chaw siv sab nraum zoov ntev ntev (xws li TV yees, txoj kev loj guardrails, thiab lwm yam). Rau cov fasteners, kub-dip galvanizing feem ntau siv tau rau bolts ntawm M6 thiab saum toj no, tab sis nws tsis tuaj yeem siv rau cov fasteners siab. Qhov laj thawj tseem ceeb yog qhov kev ua haujlwm kub ntawm cov txheej txheem kub-dip galvanizing yog qhov siab (400℃~ 500 degree), uas yog ib qho yooj yim ua rau temper softening ntawm high-strength fasteners thiab txo lawv lub zog.
2.1.2 Electrogalvanizing
Electrogalvanizing yog siv cov txheej txheem electrolysis los tsim ib qho kev sib xws, ntom thiab zoo-bonded zinc txheej rau ntawm qhov chaw ntawm cov hlau. Lub thickness ntawm electrogalvanized zinc txheej yog nyias nyias (5 ~ 30 μm), thiab nws cov corrosion kuj yog qhov phem tshaj ntawm galvanizing anti-corrosion kev kho mob. Txawm li cas los xij, nws cov txheej txheem yog qhov yooj yim, tus nqi qis, thiab nws muaj kev cuam tshuam me ntsis ntawm kev sib koom tes xov, yog li nws tau siv dav hauv fasteners. Vim tias electrogalvanizing muaj siab hydrogen embrittlement rhiab heev thiab nws yog ib qho nyuaj rau tshem tawm hydrogen tag nrho (lub electrogalvanized txheej yuav tev los yog poob thaum kub siab tshaj 100 degree), electrogalvanizing yuav siv tsis tau rau high-strength fasteners.
2.1.3 Mechanical Galvanizing
Mechanical galvanizing yog hais txog cov txheej txheem kho saum npoo uas cov hlau qhov chaw tsim cov zinc txheej los ntawm kev cuam tshuam rau saum npoo ntawm cov hlau nrog kev cuam tshuam xov xwm hauv qab kev txiav txim ntawm cov tshuaj xws li zinc hmoov, dispersant thiab accelerator. Lub thickness ntawm mechanical galvanized txheej feem ntau yog 5 ~ 50 μm. Qhov saum npoo ntawm txheej yog ntom thiab sib xws, nrog cov nyhuv zoo nkauj thiab zoo heev corrosion kuj; Tsis tas li ntawd, nws tsis muaj qhov tsis zoo xws li kub-kub tempering thiab hydrogen embrittlement uas twb muaj lawm hauv kub-dip galvanizing thiab electrogalvanizing, yog li nws yog txheej txheem kho saum npoo tshwj xeeb tshaj yog tsim rau kev tiv thaiv corrosion ntawm fasteners.
2.2 Lwm Cov Hlau Platings
2.2.1 Chromium plating
Raws li cov txheej txheem hlau, chromium muaj cov yam ntxwv ntawm qhov muaj zog adhesion, hnav tsis kam, zoo nkauj zoo nkauj, thiab kub kub tsis kam (tuaj yeem siv tau qis dua 500 degree). Yog li ntawd, nws yog qhov zoo tshaj plaws los siv chromium txheej raws li cov hlau txheej ntawm fasteners.
Lub ntsiab tsis zoo ntawm chromium plating yog raws li nram no:
1) Cov txheej txheem yog complex, thiab npib tsib xee los yog tooj liab yuav tsum tau plated ua ntej chromium plating.
2) Tus nqi siab.
3) Cov txheej txheej chromium yog tawv thiab nkig, thiab yooj yim poob tawm.
2.2.2 Nickel plating
Raws li cov txheej txheem hlau, npib tsib xee muaj cov khoom siv hluav taws xob zoo, siab tawv, zoo nkauj zoo nkauj thiab ua haujlwm kub (tuaj yeem siv tau qis dua 600 degree), yog li nws kuj yog qhov zoo tagnrho rau siv nickel plating rau fasteners.
Lub ntsiab tsis zoo ntawm nickel plating yog raws li nram no:
1) Cov txheej txheem yog complex, thiab tooj liab yuav tsum tau plated ua ntej nickel plating (tus thawj "ua ntej chromium plating" yog ib tug typo).
2) Cov txheej npib tsib xee yog ntxeem tau, thiab cov matrix corrosion yuav nrawm dua thaum cov txheej nyias nyias.
3) Tus nqi siab.
2.2.3 Cadmium plating
Raws li cov txheej txheem hlau, cadmium yog txheej txheej anodic, uas muaj cov yam ntxwv ntawm hydrochloric acid corrosion kuj, tsis tshua muaj hydrogen embrittlement thiab zoo zoo nkauj nyhuv. Nws yog tshwj xeeb tshaj yog haum rau fasteners siv nyob rau hauv marine ib puag ncig (xws li fasteners ntawm marine aircraft thiab roj drilling platforms).
Lub ntsiab tsis zoo ntawm cadmium plating yog raws li nram no:
① Muaj kuab paug ib puag ncig. Cov roj tsim tawm thaum cadmium melts thiab soluble cadmium ntsev yog tshuaj lom.
② Tus nqi siab.
2.2.4 Nyiaj Plating
Raws li cov txheej txheem hlau, nyiaj muaj hluav taws xob zoo heev, kev ua haujlwm zoo heev, lubricity zoo thiab ua haujlwm kub zoo heev (tuaj yeem siv tau qis dua 870 degree). Yog li ntawd, nyiaj plating yog dav siv nyob rau hauv teb xws li electronics thiab hluav taws xob engineering, high-frequency Cheebtsam (xws li generator conductive bolts, tsheb roj teeb qhov hluav taws xob terminals).
Lub ntsiab tsis zoo ntawm nyiaj plating yog raws li nram no:
① Cov txheej txheem yog complex, thiab tooj liab yuav tsum tau plated ua ntej nyiaj plating.
② Tus nqi kim heev.
2.2.5 Zinc-Nickel Plating
Zinc-nickel composite txheej yog ib hom tshiab ntawm alloy hlau txheej tsim los ntawm zinc plating nto kho tshuab, uas muaj ntau yam zoo:
1) Lub sijhawm nruab nrab ntsev tshuaj tsuag (NSS) tuaj yeem ncav cuag 500 ~ 1500 Hrs.
2) Lub peev xwm electrode ntawm txheej yog nruab nrab ntawm Fe thiab Zn, uas yog tsim nyog rau kev sib dhos nrog txhuas qhov chaw.
3) High txheej hardness thiab zoo zoo nkauj nyhuv.
4) Yuav luag tsis muaj hydrogen embrittlement, tuaj yeem siv rauhigh-zog fasteners.
5) Cov cua kub zoo (tuaj yeem siv tau qis dua 800 degree; tus thawj "8009C" yog typo).
Lub ntsiab tsis zoo ntawm zinc-nickel txheej yog nws tus nqi siab (kwv yees li 6 npaug ntawm qhov zoo tib yam galvanizing), tab sis nws cov kev ua tau zoo tshaj plaws tau lees paub ntau thiab ntau dua.
3. Txheej Technology
Coating technology is a surface treatment technology that applies specific coatings to the surface of objects through certain equipment and methods to form a dense, continuous and uniform film on the surface, and then dries and cures it by natural or artificial methods to form a protective or decorative coating.
Nyob rau hauv fasteners, cov txheej txheem siv ntau tshaj plaws yog zinc-chromium txheej tshuab, uas yog txheej txheej tsim rau saum npoo ntawm cov hlau los ntawm kev siv zinc-chromium txheej ntawm steel qhov chaw thiab ci los ntawm tag nrho cov txheej txheej kaw, tseem hu ua Dacromet kho. Nws muaj cov yam ntxwv zoo hauv qab no:
1) Lub sijhawm nruab nrab ntsev tshuaj tsuag (NSS) tuaj yeem ncav cuag 500 ~ 1000 Hrs.
2) Zoo permeability.
3) Tsis muaj hydrogen embrittlement rhiab heev.
4) Tsawg ib puag ncig muaj kuab paug.
5) Raws li ib tug fastener, nws torque-preload sib xws yog zoo heev.
6) Tus nqi nruab nrab (kwv yees li 2 npaug ntawm qhov zoo tib yam galvanizing).
Lub ntsiab tsis zoo ntawm kev kho Dacromet yog raws li nram no:
1) Kev hnav tsis zoo (hardness tsuas yog 1 H).
2) Ib qho xim (tsuas yog nyiaj dawb thiab nyiaj grey), cov nyhuv zoo nkauj tsis zoo.
3) Tsis zoo hluav taws xob conductivity, tsis haum rau qhov chaw nrog conductive kev twb kev txuas.
4. Hloov Microstructure ntawm Hlau
4.1 Hloov Cov Txheej Txheem (xws li Stainless Hlau)
Stainless hlau yog cov ntawv luv ntawm stainless acid-resistant steel, uas muaj corrosion kuj zoo heev thiab zoo zoo nkauj nyhuv, thiab yog dav siv nyob rau hauv ntau yam teb. Tam sim no, nws feem ntau ntseeg tias qhov kev tiv thaiv corrosion ntawm stainless hlau feem ntau yog raws li hauv qab no:
1) Thaum cov ntsiab lus Cr ntau tshaj 13%, lub peev xwm electrode ntawm cov hlau yuav nce los ntawm qhov tsis zoo rau qhov muaj peev xwm zoo, ua rau cov hlau matrix nws tus kheej "inert";
2) Cr yuav tsim ib tug tuab Cr-nplua nuj zaj duab xis nyob rau hauv steel nto los tiv thaiv cov matrix ntxiv;
3) Stainless hlau tuaj yeem muab faib ua martensitic steel, ferritic steel, austenitic steel, austenitic-ferritic stainless hlau, thiab lwm yam raws li microstructure. Ntawm lawv, austenitic stainless hlau muaj qhov zoo tshaj plaws corrosion kuj, xws li A2 thiab A4 series stainless hlau.
Stainless hlau feem ntau muaj cov nram qab no tsis zoo:
① Lub zog tsis muaj zog (feem ntau tsis ntau tshaj 300 MPa), tsis haum rau kev sib txuas ntawm cov khoom siv loj;
② Nthuav rau xov qaug dab peg: thaum stainless hlau bolts tau nruj, nws yooj yim rau kev puas tsuaj ntawm cov xov nto, thiab lub sijhawm no, cov txheej txheem oxide yuav raug tsim los ntawm tus kheej, uas yuav ua rau lub bolts adhesion thiab xauv;
③ Ncua rau intergranular corrosion: ntawm qhov kub thiab txias, C thiab Cr hauv stainless hlau yuav tsim cov tebchaw, tshwj xeeb tshaj yog nyob ze ntawm cov ciam teb, uas yuav ua rau cov tsos ntawm "Cr-depleted cheeb tsam" ntawm cov ciam teb nplej thiab ua rau intergranular corrosion;
④ Tsis zoo corrosion kuj rau Cl⁻ nruab nrab (tshwj tsis yog A4 stainless hlau);
⑤ Tus nqi siab (kwv yees li 4 npaug ntawm kev kho Dacromet).
4.2 Hloov Cov Kev Kho Mob Kub Kub
Cov ntaub ntawv hlau feem ntau yog cov txheej txheem ntau theem (tsis huv, carbides, intermetallic compounds thiab lwm theem thib ob feem ntau muaj nyob hauv cathodes hauv steel, thaum Fe matrix ua raws li anode). Nws muaj peev xwm sib txawv ntawm txhua theem hauv cov qauv multiphase, tsim kom muaj corrosion microcell. Qhov thib ob theem yuav yog anodic passivation theem lossis cathodic dissolution theem, ob qho tib si yuav cuam tshuam rau corrosion kuj ntawm matrix.
Siv cov hlau tsis muaj hlau ua piv txwv, nws cov txheej txheem vuam thiab kev kho cua sov yuav tsum tau ceev faj ntxiv. Tom qab kev kho cua kub kub, yog tias cov hlau tsis muaj cua sov ntawm 400℃thiab 850 degree, ntau tus Cr₂₃C₆ thiab Cr₇C₃ carbides yuav ua rau nag lossis daus raws li cov ciam teb, tsim thaj tsam Cr-depleted nyob ze ntawm thaj tsam ntawm cov nplej. Carbides ua raws li cathode ntawm lub cell corrosion, thiab Cr-depleted cheeb tsam ua raws li lub anode ntawm corrosion cell, yog li ua rau intergranular corrosion thiab ua rau ib tug tseem ceeb txo nyob rau hauv corrosion kuj ntawm stainless hlau.
