DACROMET HEX NUTS-Ib qho Kev Taw Qhia rau Corrosion-Resistant Fasteners 

1. Taw qhia

Hexagonal txiv ntseej, feem ntau hu ua hex txiv ntseej, yog cov feem ntau siv fasteners nyob rau hauv mechanical engineering, kev tsim kho, tsheb, thiab kev siv tshuab. Thaum ua ke nrog kev kho saum npoo av xws li Dacromet txheej, cov khoom no ua tiav qhov tshwj xeeb corrosion tsis kam, ua rau lawv haum rau cov cheeb tsam hnyav xws li marine, tsheb hauv qab, thiab kev siv sab nraum zoov.

Kab lus no muab ob txoj kev taw qhia: thawj zaug tshuaj xyuas cov qauv tsim thiab cov qauv ntawm hex txiv ntseej, thiab thib ob tshawb nrhiav Dacromet (zinc-aluminium flake) txheej tshuab uas ua rau lawv ua tau zoo thiab ua haujlwm tau zoo.

1.1 Hex ceev yog dab tsi?

Ib tug hex txiv ntseej yog ib hom fastener nrog ib tug threaded qhov thiab ib tug hexagonal txheej txheej. 6-sided geometry tso cai rau kev siv tau zoo ntawm torque siv tus qauv wrenches los yog sockets, muab kev nkag tau zoo nyob rau hauv qhov chaw kaw thaum tiv thaiv kev sib tw nyob rau hauv siab loads. Hex txiv ntseej yuav luag txhua zaus siv ua ke nrog mating ntsia liaj qhov rooj los yog stud kom clamp ob los yog ntau tshaj cov khoom ua ke.

Cov yam ntxwv tseem ceeb muaj xws li:

• Internal xov (metric los yog imperial) txuam lub bolt
• Dav thoob plaws cov tiaj tiaj (qhov loj me) thiab cov thickness tau txhais los ntawm cov qauv
• Muaj nyob rau hauv ntau qib zog (piv txwv li, Chav Kawm 8, 10, Qib 5, 8)
• Cov khoom siv: carbon hlau, hlau alloy, stainless hlau

1.2 Lub luag haujlwm ntawm Dacromet Txheej

Dacromet yog cov txheej txheem zinc-aluminium flake txheej txheej txheem (thawj tsim los ntawm Hlau Coatings International) siv los ua ib zaj duab xis nyias, tsis yog electrolytic. Nws muab kev tiv thaiv corrosion zoo dua piv nrog cov pa zinc electroplating lossis kub-dip galvanizing, tshwj xeeb tshaj yog rau cov khoom siv zog siab uas yuav tsum zam kom tsis txhob muaj hydrogen embrittlement. Cov txheej txheej feem ntau tshwm xim xim nyiaj-grey thiab ntsuas tsuas yog 5-12 μm hauv tuab, khaws cov xov haum thiab qhov tseeb.

2. Hex ceev: Tsim, qauv & qhov ntev

2.1 Hom Hex Ceev

Muaj ntau qhov sib txawv kom tau raws li qhov xav tau ntawm kev ua haujlwm sib txawv:

• Txheem (Tiav) Hex Txiv Ntoo - Lub hom phiaj dav dav, feem ntau daim ntawv (ISO 4032 / DIN 934 / ASME B18.2.2).
• Heavy Hex Txiv Ntoo - Loj dua dav thoob plaws cov tiaj tiaj thiab ntau dua tuab rau kev siv cov qauv (xws li ASTM A563).
• Jam (Thin) Txiv Ntoo - Txo cov tuab rau kev xauv lossis siv qhov chaw txwv.
• Nylon-Insert Lock Nut (Nylock) - Prevailing-torque locking feature.
• Flange Nut - Kev sib xyaw ua ke lub ntsej muag rau kev txhim kho kev xa khoom.

2.2 Metric Hex Txiv Ntoo Dimensions (ISO 4032 / DIN 934)

Cov lus hauv qab no qhia txog qhov tseem ceeb ntawm qhov loj me ntawm cov qauv hex txiv ntseej:

Table 1: Xaiv metric hex txiv ntseej qhov ntev (kwv yees qhov tseem ceeb raws li ISO 4032 / DIN 934).

2.3 Qib Siab & Cov Khoom Siv

Hex txiv ntseej raug muab qhab nia raws li cov qauv khoom siv tshuab. Cov chav kawm metric feem ntau suav nrog Chav Kawm 6, 8, thiab 10 (ISO 898-2). Cov chav kawm siab dua sib raug rau cov ntaub ntawv pov thawj dua thiab hardness. Rau cov qauv siv, hnyav hex txiv ntoo ua raws li ASTM A563 lossis EN cov qauv yog nyiam. Cov pa roj carbon steel yog cov khoom siv ntau tshaj plaws; stainless hlau (A2 / A4) yog siv thaum muaj kev tiv thaiv corrosion, txawm hais tias Dacromet-coated carbon steel feem ntau muab cov nqi zoo dua rau kev ua haujlwm siab.

3. Dacromet Txheej Technology

3.1 Kev sib xyaw thiab cov qauv

Dacromet yog dej-raws li, uas tsis yog-electrolytic txheej muaj feem ntau ntawm overlapping zinc thiab txhuas flakes dispersed nyob rau hauv ib tug inorganic chromium-oxide binder. Cov yeeb yaj kiab uas tau tshwm sim yog nyias (feem ntau 5-12 μm), cov xim hlau zoo nkauj, thiab muab kev tiv thaiv ntau txheej:

• Barrier tiv thaiv - Flake txheej cais cov substrate los ntawm corrosive media.
• Galvanic (sacrificial) tiv thaiv - Zinc ua raws li anode, nyiam corroding.
• Passivation - Hlau oxides qeeb cov tshuaj tiv thaiv corrosion.
• Kev kho tus kheej - Zinc oxides thiab carbonates tsiv mus rau qhov chaw puas.

3.2 Cov txheej txheem thov

Cov txheej txheem raug ua ntu zus zam cov kua qaub pickling, yog li tshem tawm txoj kev pheej hmoo ntawm hydrogen embrittlement:

1. Kev npaj nto: Alkaline degreasing + mechanical descaling (shot blasting).
2. Daim ntawv thov txheej: Dip-spin (feem ntau yog rau fasteners), tshuaj tsuag, los yog dip-drain.
3. Flash-off / ua ntej ziab ntawm qhov nruab nrab kub kom tshem tawm cov dej.
4. Thermal curing ntawm kwv yees li 280-320 ° C los tsim cov inorganic matrix.

3.3 Corrosion Performance

Kev ua tau zoo feem ntau raug ntsuas los ntawm kev ntsuas nruab nrab ntsev-txheej txheem (ISO 9227 / ASTM B117). Cov txiaj ntsig zoo rau Dacromet 320/500 systems tau qhia hauv qab no:

Table 2: Kev ua haujlwm zoo ntawm Dacromet coatings (qhov tshwm sim nyob ntawm substrate, geometry, thiab txheej txheem).

Cov txiaj ntsig ntxiv muaj xws li kub tsis kam mus txog kwv yees li 300 ° C, kev pleev xim zoo, tswj coefficient ntawm kev sib txhuam (tshwj xeeb tshaj yog nrog lubricated topcoats xws li PLUS los yog DACROLUB), thiab compatibility nrog txhuas (txo galvanic corrosion kuj).

4. Daim ntawv thov, kev sib piv & Cov lus xaus

4.1 Hom Kev Siv Dacromet Hex Ceev

Vim tias lawv cov kev sib xyaw ua ke ntawm lub zog siab, cov duab kos duab meej, thiab qhov zoo tshaj plaws corrosion tsis muaj kev pheej hmoo hydrogen-embrittlement, Dacromet-coated hex txiv ntseej yog dav teev nyob rau hauv:

• Automotive: chassis, underbody, cav thiab kis tau tus mob fasteners (feem ntau Qib 10.9 / Chav Kawm 10).
• Cov khoom siv hauv hiav txwv thiab ntug hiav txwv: trailers, winches, cov khoom siv kho vajtse.
• Kev tsim kho thiab infrastructure: sab nraum zoov steel qauv, txuas hniav, guardrails.
• Cua zog thiab cov tshuab hnyav: lub zog siab bolted pob qij txha raug huab cua.
• Railway thiab cov khoom siv ua liaj ua teb xav tau kev pab lub neej ntev hauv corrosive atmospheres.

4.2 Sib piv nrog lwm txheej txheej

Table 3: Sib piv cov txheej txheem ntawm cov txheej txheem fastener.

4.3 Xaus

Dacromet hex txiv ntseej sawv cev rau kev paub tab, kev ua tau zoo tshaj plaws uas ua ke nrog kev ntseeg siab ntawm cov txheej txheem hexagonal fasteners nrog qib siab zinc-aluminium flake corrosion tiv thaiv. Lawv cov txheej txheej nyias nyias khaws cov xov geometry thiab tshem tawm cov kev txhawj xeeb ntawm hydrogen-embrittlement cuam tshuam nrog cov txheej txheem electrolytic, ua rau lawv tshwj xeeb tshaj yog haum rau cov qib siab zog siv hauv kev nyab xeeb-tseem ceeb lossis lub neej ntev kev siv sab nraum zoov.

Thaum xaiv cov fasteners, engineers yuav tsum xav txog qhov tshwj xeeb corrosion ib puag ncig, xav tau kev pabcuam kub, torque / kev sib txhuam, thiab cov hom phiaj nqi. Hauv ntau lub tsheb, dej hiav txwv, thiab kev tsim kho vaj tse, Dacromet-coated hex txiv ntseej xa cov txiaj ntsig zoo ntawm kev ua tau zoo, kev ntseeg tau, thiab tag nrho cov nqi ntawm lub neej.

Raws li cov kev cai ib puag ncig txuas ntxiv txhawb cov chromium-txo lossis chromium-dawb lwm txoj hauv kev (piv txwv li, Geomet® systems), cov tsev neeg zinc-flake txheej txheej tseem yog cov cuab yeej nyiam rau niaj hnub corrosion-resistant fastening daws.