Dacromet-Coated Bolts uye Nuts

2026-10-28

1. Nhanganyaya

A threaded connection yakasimba chete sechikamu chayo chisina kusimba. Yekutanga Dacromet-yakavharwa hex bhoti yakakandwa mune yakachipa zinc-plated nati haisi corrosion-protection system - ndeye galvanic cell kumirira kukundikana. Iyo zinc-plated nati inova anode mune vaviri, corrodes zvakaringana, inobata patambo dzebhaudhi, uye chibatanidza chese chinorasikirwa nekusungirira kwaro nguva refu bhaudhi risati raratidza chero ngura tsvuku.

Nechikonzero ichi, nyanzvi fastener yakatarwa nguva dzose kubata mabhaudhi, nzungu uye washer seimwe inofananidzwa necorrosion-protection package. Dacromet (zinc-aluminium flake, non-electrolytic) coating ndiyo nzira yekusarudza pasuru iyi: inopa shinda yega yega - murume nemukadzi - mutete (5-12 μm), yunifomu, hydrogen-isina firimu inotsungirira maawa 500-1,000 yekusarerekera munyu spray (NSS) kuratidzwa pasina chena ngura kuputika kana tsvuku ngura.

Ichi chinyorwa chinotsanangura mhuri dzinosungirirana dzakabatanidzwa, nzira dzekuora dzinorwisa majoini ane shinda, nei Dacromet ichipfeka mabhaudhi nenzungu zvakafanana, uye nzira yekutsanangura uye kuunganidza inofananidzwa bhoti-nut-washer seti.

2. Iyo Corrosion Inorwisa sei Iyo Threaded Joint

Threads ndidzo dzinonyanya corrosion-pableble geometry pane chero fastener assembly:

1.Crevice corrosion- mukaha wemicroscopic pakati pebhaudhi shinda neshinda yenati inoteya hunyoro uye electrolyte, ichigadzira mukaha une nzara yeoxygen uko nzvimbo dzeanodic dzinoumba uye pitting inotanga;

2.Galvanic corrosion- mabhaudhi akasiyana-siyana kana simbi (Dacromet bolt ine electro-plated nut, bhaudhi isina tsvina mune galvanized nut) dhiraivha yakasarudzika corrosion yechikamu chisina kunaka;

3.Coating kukanganisa pagungano- shinda dzinokwenya uye nduru panguva yekusimbisa; electroplate yakaonda uye pendi yependi inotemwa nyore nyore, ichifumura simbi isina chinhu mumidzi yeshinda;

4.Stress concentration- tambo yekutanga inotakura mutoro inotakura mugove usingaenzaniswi we preload, saka makomba ekuora ipapo anokurumidza kuve akatsemuka kuneta;

5.Fretting pasi pekudengenyeka- micro-movement pakati pezviso zvinotakura inokanganisa firimu, ichikoka tsvina yakachena uye ipapo tsvuku tsvuku.

Kana zvinhu zvakaita ngura zvawanda mushinda, nati inobata, disassembly torque inodarika torque yekuisa, uye bhaudhi kana stud kazhinji inofanirwa kutemwa - iyo yekare "chando nut" kutadza mukugadzirisa munda.

3. Corrosion Resistance yeMatched Set

Coating system (bhaudhi + nzungu + washer)	Ukobvu	NSS kuita ngura tsvuku	Thread fit mushure mekuputira	Hydrogen embrittlement	Mari yakaenzana
Plain / self-ruvara, mafuta	—	<24 h	Excellent	Hapana	Pazasi
Zinc ndiro + blue chromate	5 μm	≈ 48 h	Zvakanaka	High	Low
Zinc ndiro + gobvu tri-passivate	8–12 μm	120–240 h	Zvakanaka	High	Low-pakati
Mechanical galvanizing	20–50 μm	300–800 h	Zvakanaka	Yakaderera kwazvo	Pakati
Kupisa-dip galvanizing (nzungu yakadzvanywa zvakare)	45–85 μm	500–1,500 h	Kudzvanya zvakare kunodiwa	Low	Pakati
Dacromet Kirasi 2 (flZn 8)	8 μm	≈ 720 h	Excellent	Hapana	Pakati
Dacromet Kirasi 3 / dema	10–12 μm	≈ 1,000 h	Excellent	Hapana	Pakati-pamusoro

Tafura 1. Coating systems for bolt-nut assemblies ichienzaniswa (yakajairika indasitiri kukosha).

Nekuti iyo yekupfekedza inoiswa kune yakapedzwa, inopisa-yakagadziriswa zvikamu uye yakaporeswa pazasi tembiricha yekudziya, zvese mabhaudhi nenzungu zvinochengeta yavo yakazara mechanical zvivakwa - tensile simba, humbowo mutoro uye kuoma pane ISO 898-1 / ISO 898-2 - isina kuchinjika.

4. Gungano Maitiro Akanakisisa

1.Never kusanganisa coating systems- pair Dacromet bolts chete neDacromet nuts uye washers; vaviri vakavhengana vanotyaira galvanic corrosion yeiyo isina simba (kazhinji zinc-plated) chikamu;

2.Remekedza tafura ye torque- lubricated Dacromet pairs vane yakaderera, yakagadzikana nut factor pane isina simbi; kushandisazve ma torque echinyakare kunowedzera kuomesa uye kunogona kubvisa shinda dze nzungu;

3.Usazora mafuta zvakare- iyo yakasanganiswa topcoat yatoisa iyo friction coefficient; mamwe mafuta pashinda anochinja K zvisingatarisike;

4.Mind iyo jam-nut order- apo nut yakaonda uye nut yakazara yakarongedzerwa (classic locking arrangement), simbisai nut yakazara kurwisana nehutete hutete;

5.Watch for gallingpamateya asina tsvina - Dacromet's lubricant topcoat zvakare inoderedza galling njodzi pastainless studs;

6.Verify yekutanga-chinyorwa torque-tensionpane yekuyedza skid, uchishandisa iyo chaiyo bhaudhi-nut-washer musanganiswa kubva kune yekugadzira yakawanda.

5. Mhedziso

Corrosion kutadza kashoma kutangira pashank yebhaudhi - inotanga mushinda, mumukaha pakati pebhaudhi nenati. Naizvozvo kubatana kwakasimba kunoda a inofananidzwa necorrosion-protection package: Dacromet-yakavharwa mabhaudhi, nzungu uye washers mune imwechete zinc-flake system, inotsanangurwa pamwe chete (ISO 10683 / ASTM F1136, flZn 8/10, ≥ 720 h NSS), yakaunganidzwa neiyo torque chaiyo uye friction values. Mhedzisiro ndeye tambo yekubatanidza inoramba chena ngura, tsvuku ngura, gomba, kurwiswa kwemugodhi uye kubatwa - kuburikidza nemakore emunyu wekupfapfaidza, mamiriro ekunze uye vibration.

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