Galvanized Fasteners Guide - Kub Dip vs Electroplating vs Mechanical Plating

Vim li cas Fasteners Xav Tau Galvanizing?

Corrosion Mechanism - Oxidation ntawm Carbon Steel / Alloy Steel nyob rau hauv Cua

Cov pa roj carbon steel thiab alloy steel fasteners corrode thaum raug oxygen thiab ya raws, ua rau hlau oxide (xeb) uas ua rau tus ntoo khaub lig tsis muaj zog -section thiab tuaj yeem ua rau lub fastener tsis ua haujlwm. Tus nqi corrosion nyob ntawm ib puag ncig xws li av noo, kub, atmospheric pollutants (SO2, chlorides), thiab raug rau cov tshuaj. Nyob rau hauv ib puag ncig kev lag luam sab nraum zoov, cov pa roj carbon steel fasteners uas tsis muaj kev tiv thaiv tuaj yeem poob qhov tseem ceeb -section hauv 1-5 xyoo, yuav tsum tau them nqi hloov thiab nthuav tawm kev pheej hmoo ntawm kev nyab xeeb hauv kev siv cov qauv.

Zinc Sacrificial Anode Protection Txoj Cai

Galvanizing tiv thaiv hlau los ntawm kev txi anode mechanism - zinc yog ntau electrochemically nquag tshaj hlau, yog li nws corrodes nyiam dua thaum lub txheej raug rau ib qho electrolyte. Txawm hais tias cov txheej txheej yog khawb los yog puas, cov zinc nyob ib puag ncig tseem tiv thaiv cov hlau raug los ntawm kev ua galvanic. Qhov no tus kheej -kho tus yam ntxwv ua rau galvanizing deb tshaj rau cov txheej thaiv txheej (xws li xim) ntev - lub sij hawm tiv thaiv corrosion ntawm fasteners nyob rau hauv ib puag ncig hnyav.

Galvanizing yog tus nqi tshaj plaws -Txoj kev tiv thaiv zoo-Txoj kev Corrosion rau Fasteners

Ntawm txhua txoj kev tiv thaiv corrosion rau fasteners, galvanizing muaj qhov zoo tshaj plaws sib npaug ntawm kev tiv thaiv qib piv rau tus nqi. Tus nqi pib tus nqi tshaj qhov yooj yim fasteners yog me me (feem ntau 20-40% rau electroplating, 30-60% rau kub-dip galvanizing), thaum lub sij hawm kev pab cuam lub neej ncua li ntawm 3-5 zaug rau electroplating rau 10-20 zaug rau kub-dip galvanizing piv rau cov pa roj carbon tsis muaj kev tiv thaiv. Thaum lub neej tu thiab hloov cov nqi raug txiav txim siab, galvanized fasteners xa tus nqi qis tshaj ntawm cov tswv cuab nyob rau hauv feem ntau sab nraum zoov thiab corrosive ib puag ncig.

Kub Dip Galvanizing (HDG)

Txheej txheem - Immersion hauv Molten Zinc Bath ntawm Ntau dua lossis sib npaug li 450 degree

Kub-dip galvanizing suav nrog immersing ntxuav thiab fluxed fasteners rau hauv da dej ntawm zinc molten ntawm kwv yees li 450℃. Cov zinc molten reacts nrog cov hlau nto los ua ib tug series ntawm zinc - hlau intermetallic alloy txheej (gamma, delta, thiab zeta theem) overlaid nrog ib txheej ntawm cov zinc ntshiab. Qhov no metallurgical daim ntawv cog lus muab txheej adhesion superior rau txhua qhov siv txheej txheej. Lub sij hawm cov tshuaj tiv thaiv, tshem tawm tus nqi, thiab da dej chemistry tswj cov txheej thickness thiab microstructure.

Txheej Thickness thiab Los tiv thaiv -Corrosion Life

Kub-dip galvanized txheej ntawm fasteners feem ntau yog li ntawm 45 mus rau 85 μm (1.8 mus rau 3.4 mils), nrog cov txheej tuab ua rau ntawm txoj kab uas hla loj dua thiab lub sij hawm ntev immersion. Kev tiv thaiv corrosion lub neej ntawm HDG fasteners yog ncaj qha proportional rau txheej thickness - nyob rau hauv ib txwm muaj kev lag luam ib puag ncig, 45 μm muab 20-30 xyoo kev tiv thaiv, thaum 85 μm tuaj yeem txuas mus rau 50+ xyoo. Nyob rau hauv ib puag ncig marine nrog ntau dua corrosivity, tib txheej muab 15-25 xyoo ua ntej corrosion tseem ceeb.

Qhov zoo thiab qhov tsis zoo

Qhov zoo tshaj plaws ntawm HDG yog cov zinc txheej tuab tshaj plaws ntawm txhua txoj kev galvanizing, kev tiv thaiv corrosion zoo tshaj plaws, kev tiv thaiv zoo heev, thiab kev tiv thaiv tiav nrog rau cov xov sab hauv (yog tias tsis npog). Qhov tsis zoo muaj xws li: threads xav tau tom qab-tapping (cov txiv ntseej loj), cov ntsej muag ntxhib, qhov kub ntawm 450℃txheej txheem tuaj yeem cuam tshuam rau cov khoom siv hluav taws xob ntawm siab -lub zog quenched thiab tempered bolts, thiab pickling ua ntej galvanizing qhia hydrogen embrittlement kev pheej hmoo rau siab -.

Electroplating (Electro{0}}Galvanizing)

Txheej txheem thiab txheej txheej

Electro-galvanizing deposits zinc los ntawm cov tshuaj electrolyte mus rau fastener nto los ntawm electrolytic deposition. Cov txheej tuab yog tswj hwm los ntawm kev kho qhov ceev tam sim no thiab lub sijhawm plating, feem ntau ua rau 5-15 μm tso nyiaj. Qhov saum npoo yog du thiab ci, nrog rau kev xaiv passivation kev kho mob uas ua rau xiav-dawb, daj (ntau xim), lossis xim dub tiav uas txhim kho corrosion kuj thiab muab cov xim pleev xim coding. Electroplating tswj qhov tseeb xov qhov ntev thiab haum rau feem ntau fastener xov cov chav kawm yam tsis muaj oversize hloov.

Daim ntawv thov thiab kev txwv

Electroplated fasteners yog tsim rau kev siv sab hauv tsev, ib puag ncig qhuav, thiab sab nraum zoov sab nraud uas yuav tsum muaj kev tiv thaiv corrosion yog 1-5 xyoos. Lawv yog qhov kev xaiv pheej yig tshaj plaws rau kev siv dav dav - lub hom phiaj fasteners hauv cov tsev lag luam, tsheb sib dhos, tshuab, thiab cov khoom siv. Qhov kev txwv tseem ceeb yog txheej txheej nyias - nyob rau hauv qhov chaw sab nraum zoov lossis marine ib puag ncig, cov txheej yog siv sai heev thiab corrosion pib ntawm substrate.

Mechanical Galvanizing

Txheej txheem - Mechanical Impact Deposition ntawm Chav Kub

Mechanical galvanizing siv zinc hmoov rau fasteners nyob rau hauv lub rotating chim nrog iav hlaws thiab tshuaj accelerators nyob rau hauv chav tsev kub. Kev cuam tshuam ntawm cov hlaws dai hammers zinc hmoov rau ntawm qhov chaw fastener, tsim ib txheej ntawm 20-50 μm thickness. Vim tias cov txheej txheem ua haujlwm ntawm qhov kub thiab txias, tsis muaj qhov cuam tshuam thermal ntawm cov khoom siv fastener thiab tsis muaj hydrogen embrittlement los ntawm pickling - qhov kev kho ua ntej tsuas yog cov kua qaub me me uas tsis tsim cov hydrogen tseem ceeb.

Qhov zoo rau High Strength Bolts

Mechanical galvanizing yog txoj kev nyiam zinc txheej rau siab - lub zog bolts nrog hardness saum 38 HRC, tshwj xeeb tshaj yog ASTM A490 thiab ISO 12.9 qib uas muaj feem cuam tshuam rau hydrogen embrittlement. Cov txheej tuab ntawm 20-50 μm muab kev tiv thaiv corrosion ntawm electroplating thiab HDG, nrog ntsev tsuag tsis kam ntawm 500-1000 teev. Mechanical galvanizing kuj tseem haum rau threaded fasteners qhov ntev ntev yuav tsum tau khaws cia, raws li cov txheej txheem kuj zoo ib yam.

Kev sib piv ntawm Peb Txoj Kev Galvanizing

Cov nyhuv ntawm Galvanizing ntawm Xov Tolerance

Kub-dip galvanizing ntxiv cov txheej tuab tshaj plaws rau cov xov, xav tau cov txiv ntoo kom tau tapping nrog cov xov sab hauv loj (feem ntau yog hloov kho chav kawm 2B lossis 3B haum) kom muaj kev sib dhos kom zoo. Qhov yuav tsum tau muaj ntau tshaj yog teev nyob rau hauv ASME B1.1 rau galvanized threads, nrog rau kev tso cai nyob ntawm cov txheej thickness. Electroplating feem ntau tsis tas yuav hloov qhov loj me me vim tias cov txheej txheej yog nyias txaus kom haum raws li tus qauv xov kam rau ua. Cov txheej txheem galvanizing nyob rau hauv thaj tsam ntawm 20-30 μm feem ntau haum nyob rau hauv cov qauv xov txwv, tab sis cov txheej tuab (40-50 μm) yuav xav tau cov txiv ntseej loj zoo ib yam li HDG.

Hydrogen Embrittlement nyob rau hauv Galvanized Fasteners

Hydrogen embrittlement tshwm sim thaum hydrogen atoms generated thaum lub sij hawm pickling (acid tu) los yog electroplating diffuse mus rau hauv cov hlau lattice thiab accumulates nyob rau hauv grain ciam teb los yog inclusions, txo ductility thiab ua rau ncua nkig tawg nyob rau hauv sustained tensile kev nyuaj siab. Siab - lub zog bolts (Ntau dua lossis sib npaug rau 10.9 qib lossis Ntau dua lossis sib npaug rau 38 HRC) yog qhov cuam tshuam tshaj plaws. Ci ntawm 190-220℃rau 4-24 teev tom qab plating tuaj yeem tshem tawm cov hydrogen diffusible thiab txo qhov kev pheej hmoo ntawm embrittlement, tab sis tsis tshem tawm tag nrho. Mechanical galvanizing yog qhov kev daws teeb meem zoo tshaj plaws rau cov bolts muaj zog vim tias cov txheej txheem tsis tsim hydrogen. ASTM A490 bolts feem ntau txwv tsis pub kub-dip galvanizing thiab electroplating vim li no.

ManufacturerPipe's Galvanized Fastener Peev Xwm

ManufacturerPipe muaj tag nrho peb txoj hauv kev galvanizing - electroplating, mechanical galvanizing, thiab kub-dip galvanizing - kom phim txhua daim ntawv thov kev tiv thaiv corrosion thiab cov kev txwv qib zog. Peb cov khoom siv hluav taws xob galvanizing muaj siab ua haujlwm siab - siv lub zog ntsia hlau (A325 / A490 thiab 10.9 / 12.9 qib) xav tau hydrogen embrittlement- ua haujlwm dawb. Peb muab cov ntawv qhia txog tshuaj tsuag ntsev thiab cov txheej thickness ntsuas nrog txhua qhov khoom xa tuaj, thiab txhawb nqa tsis yog - tus qauv ntev thiab batch customization rau ib qho twg.

Xav tau Galvanized Fasteners rau koj daim ntawv thov?

Hu rau ManufacturerPipe rau txoj cai galvanizing kev daws teeb meem raws li koj qhov chaw pabcuam thiab qib zog.