Welding a wɔde yɛ adwuma Galvanized Steel da so ara yɛ adeyɛ a wɔahyɛ da ayɛ wɔ mfiridwuma mu nneɛma a wɔyɛ ne adansi ho mfiridwuma nyinaa mu. Zinc a wɔde akata so a ɛyɛ den no ma ɛko tia nsɛe yiye. Eyi ma saa nneɛma yi ho hia ma abɔnten so mmeae a emu yɛ den ne nnwuma a ɛyɛ den a wɔde bɛyɛ nnwuma.
Nanso, saa nneɛma yi a wɔde bɛka abom no de dade ne ahobammɔ ho nsɛnnennen soronko ba bere a wɔde toto adwuma a wɔyɛ wɔ dade a ɛyɛ carbon a ɛda hɔ kwa ho no. Zinc a ɛbɔ ho ban no de ntawntawdi ba tẽẽ. Wobɛhyia nsɛm a ɛfa arc stability, weld pool ahotew, ne adwumayɛfo akwahosan ho. Worentumi mmɔ arc kɛkɛ wɔ ade a wɔde kata so no so na woahwɛ kwan sɛ wobɛnya nkwaa a ɛho tew na ɛyɛ den a nea ebefi mu aba no aniberesɛm biara nni ho.
Saa akwankyerɛ yi de nhyehyɛe a egyina adanse so ma mfiridwumayɛfo, fabrication managers, ne adetɔ akuw. Yɛbɛhwɛ prep ahwehwɛdeɛ a ɛyɛ ahyɛdeɛ, nhyehyɛeɛ a ɛyɛ papa a wɔpaw, ne gyinapɛn a ɛho hia a ɛfa mmara sodiɛ te sɛ OSHA ne AWS. Wubesua sɛnea wobɛkɔ so akura nhyehyɛe no mudi mu na woabɔ w’adwumayɛfo ho ban yiye.
Nneɛma Titiriw a Wɔde Kɔ
Ɛyɛ yie sɛ wɔbɛtumi ayɛ dadeɛ a wɔde galvanized ayɛ, sɛ wɔdi ahosiesie a ɛyɛ katee ansa na wɔadi weld no ani ne akyire a wɔde kata so (ASTM A780) akyi a.
Zinc yɛ vaporizes wɔ ~420°C, ɛde weld pool efĩ, porosity, ne akwahosan ho asiane a emu yɛ den (Metal Fume Fever) ba sɛ wɔamfa PPE ne mframa a ɛfata nni dwuma a.
Adeyɛ a wɔpaw no ho hia: Flux-Cored Arc Welding (FCAW) ne Shielded Metal Arc Welding (SMAW/Stick) di trace zinc ho dwuma yiye sen Gas Metal Arc Welding (MIG), bere a ɛsɛ sɛ wɔkwati Gas Tungsten Arc Welding (TIG) denneennen esiane sɛ wɔte nka kɛse wɔ trace zinc ho nti.
Wɔma ɔdan no mudi mu kura: Sɛnea ILZRO nhwehwɛmu kyerɛ no, weld a wɔayɛ no yiye wɔ dade a wɔde galvanized ayɛ so no ne sɛnea dade nkwaa a wɔmfa nkata so no mu paapae ne ɔbrɛ ahoɔden hyia.
Abɔde mu Nneɛma a Ɛfa Welding Galvanized Steel Ho: Asiane a Ɛwɔ Nneɛma a Wɔde Yɛ Adwuma Mu
Sɛ wobɛte nea enti a nneɛma a wɔde galvanized ayɛ no nyɛ ade yiye wɔ arc ase ase a, ɛsɛ sɛ wohwɛ thermodynamics a ɛwɔ ase no. Asɛm titiriw no gyina ɔhyew mu nsonsonoe kɛse a ɛda ade a wɔde kata so a ɛbɔ ho ban ne dade a wɔde gyina so no ntam no so.
Zinc nwene wɔ bɛyɛ 420°C (788°F). Ɛyɛ nwini koraa bɛyɛ 906°C (1663°F). Carbon dade hia ɔhyew a ɛkorɔn kɛse na ama ayɛ hyew, mpɛn pii no ɛyɛ 1370°C kosi 1500°C (2500°F kosi 2732°F). Sɛ wode welding arc gu so a, zinc a ɛwɔ mu no dan mframa a ɛyɛ hyew bere tenten ansa na dade a ɛwɔ ase no afi ase mpo ayɛ nsu.
Atadeɛ |
Nsuo a Ɛyɛ Nwene |
Vaporization Point a Ɛwɔ Hɔ |
Suban a Ɛwɔ Arc |
Carbon Dade a Wɔde Yɛ Nneɛma |
~1370°C - 1500°C na ɛyɛ nea ɛwɔ hɔ |
~3000°C na ɛwɔ hɔ |
Forms stable molten ɔtare |
Zinc a Wɔde Kata So |
~420°C na ɛwɔ hɔ |
~906°C na ɛwɔ hɔ |
Ɛma ɛyɛ hyew wɔ ɔkwan a ɛpae so |
Sɛ wɔanbrɛ ase a, saa zinc a ayɛ vaporized yi bɛkyere wɔ weld pool a ɛyɛ den no mu. Mframa ahurututu no bɔ mmɔden sɛ ebeguan dade a ɛyɛ nsu a ɛyɛ nnam no ansa na ayɛ nwini. Saa afiri yi ma emu nsunsuanso a emu yɛ den ba. Wubehu nso sɛ slag a emu yɛ duru a ɛka ho ne fusion a ɛtaa ntumi nkɔ weld nansoaa no ho.
Welding tẽẽ wɔ coating no so da so ara yɛ structure ho asodi a emu yɛ den. Ɛsɛ sɛ wofa zinc a ɛwɔ mu no sɛ efĩ a ɛyɛ hu wɔ beae a ɔhyew a ɛwɔ hɔ ntɛm ara (HAZ) no mu. Mmɔden biara a wɔbɛbɔ sɛ wɔbɛhyew afa ade a wɔde kata so no mu a wonsiesiee ne ho no bɛma nkwaa no ahoɔden asɛe na akanyan apete a ɛboro so a wontumi nhu.
Akwahosan mu Asiane ne Nneɛma a Atwa Yɛn Ho Ahyia a Wɔdi So (OSHA & AWS Gyinapɛn) .
Wɔ nhyehyɛe mu sintɔ ahorow akyi no, zinc a ɛma ɛyɛ hyew no de asiane kɛse ba abɔde a nkwa wom mu. Sɛ arc no bɔ ade a wɔde kata so no a, ɛma zinc oxide wusiw fitaa a ɛyɛ den ba. Sɛ wohome wusiw a awuduru wom yi a, ɛde tebea bi a wɔfrɛ no Metal Fume Fever ba tẽẽ.
Metal Fume Fever kanyan sɛnkyerɛnne ahorow a emu yɛ den a ɛte sɛ atiridiinini. Adwumayɛfo taa bɔ amanneɛ sɛ awɔw a emu yɛ den, atiridiinini kɛse, akisikuru, ɔbrɛ, ne dɛ a ɛda nsow wɔ anom. Mpɛn pii no, saa sɛnkyerɛnne ahorow yi ba bere a wɔawie adwuma no akyi nnɔnhwerew pii. Wobetumi ama obi a ɔyɛ adwuma no ayɛ nea ontumi nyɛ hwee koraa.
Nnwumakuw no kura anansesɛm pii a asiane wom a ɛfa awuduru a zinc wɔ ho. Ɛsɛ sɛ yɛma abɔde a nkwa wom ankasa no mu da hɔ na ama yɛabɔ adwumayɛfo ho ban yiye.
Nea edi kan no, zinc yɛ nea nsu tumi nwura mu. Onipa nipadua no yɛ nneɛma a ɛsakra na ɛyi fi mu bere kɔ so. Nea ɛnte sɛ kɔbere anaa hexavalent chromium a wɔde hyɛ obi mu no, zinc oxide a wɔhome no mma dade a emu yɛ duru nboaboa ano bere tenten. Yare no kɔ so yɛ mmerɛw kɛse nnɔnhwerew 24 kosi 48, nanso ɛntaa nsɛe nhyehyɛe no bere tenten.
Nea ɛto so abien no, nufusu a wɔnom no mma abɔde mu ahobammɔ biara nni zinc oxide a wɔhome ho. Eyi da so ara yɛ anansesɛm a atrɛw wɔ sotɔɔ ahorow mu. Nufusu kɔ yafunu mu. Wusiw kɔ ahurututu mu. Nufusu a wɔde wɔn ho to so sɛ ade a wɔde bɔ wɔn ho ban no de wɔn a wɔyɛ adwuma no to asiane mu tẽẽ.
OSHA mmara ne ANSI/ASC Z-49.1 gyinapɛn ahorow a wodi so denneennen no hwɛ hu sɛ adwumayɛbea a ahobammɔ wom. Ɛsɛ sɛ wode mfiridwuma ho nhyehyɛe ne mfiri a ɛfata a wode bɔ w’ankasa ho ban di dwuma.
Source Extraction: Fa mframa a wɔde fi mframa mu a ɛwɔ mpɔtam hɔ di dwuma tẽẽ wɔ weld beae no. Ɛsɛ sɛ wɔn a wɔde yi wusiw no twe wusiw no fi baabi a nea ɔyɛ adwuma no home no.
Ɔhome mu Ahobammɔ: Ɛsɛ sɛ wɔn a wɔyɛ adwuma no hyɛ ɔhome afiri a wɔde akatawia fã a wɔde P100 HEPA filters ahyɛ mu.
Advanced Systems: Sɛ wopɛ mmeae a wɔato mu anaasɛ kɔ so yɛ nneɛma a, hyɛ sɛ wɔmfa Powered Air-Purifying Respirators (PAPR) a wɔde ahyɛ welding dade kyɛw no mu nni dwuma.
Mframa a Wɔde Bɛma Mframa a Ɛwɔ Hɔ Kɛse: Hwɛ sɛ mframa a wɔde sesa sotɔɔ ahorow a atwa yɛn ho ahyia no di nneɛma a atwa yɛn ho ahyia ho ahobammɔ a ɛba fam koraa no ho dwuma.
Pre-Weld Ahosiesie: '1-4 Inch' Mmara no
Ahosiesie a wɔyɛ wɔ asase ani no na ɛkyerɛ sɛnea nkwaa no bedi nkonim koraa. Amerika Welding Fekuw no de akwankyerɛ a emu yɛ den ma wɔ AWS D-19.0 ase a wɔde siesie dade a wɔde akata so. Aban gyinapɛn hwehwɛ sɛ wɔn a wɔyɛ adwuma no yi zinc a wɔde akata so no nsateakwaa 1 kosi 4 (anyɛ yiye koraa no, 10-25mm) fi weld joint a wɔpɛ sɛ wɔyɛ no afã abien no nyinaa.
Wowɔ akwan titiriw abien a wobɛfa so ayi ade a wɔde kata so no afi hɔ. Ɔkwan biara kura mfaso ne anohyeto pɔtee bi.
Mfiri a Wɔde Yi Fi Mu (Wɔpɛ): Fa diski a ɛyɛ den a wɔde twitwiw nneɛma anaasɛ abrasive flap wheel di dwuma. Yam nkwaa no kɔ fam ma ɛnyɛ dade a ɛhyerɛn na ɛda hɔ kwa. Saa kwan yi yɛ ntɛmntɛm na etu mpɔn kɛse. Nanso, gye asiane a ɛwɔ dwumadie mu no tom. Sɛ wɔyam denneennen mpo a, ɛtaa ma zinc a ɛyɛ nketenkete a ɛyɛ ketewaa bi hyɛ dade no ani.
Nnuru a Wɔde Yi Fi Mu: Fa nnuru a wɔde twitwiw nneɛma te sɛ muriatic acid a wɔde vinegar fitaa aka ho di dwuma. Eyi yi zinc no fi hɔ yiye a ennyi dade a ɛwɔ ase no mfi hɔ. Ɛsɛ sɛ wode neutralization a ɛyɛ katee di dwuma wɔ ɛno akyi. Sɛ wɔantumi anhohoro acid no na wɔantumi ansɛe no a, ɛma dade a ɛda adi no so yɛ hyew ntɛmntɛm.
Scale na ɛkyerɛ ɔkwan a wobɛfa so asiesie wo ho. Mmirikatu akɛse a ɛkɔ so a wodi ho dwuma fi a galvanized dade coil taa hia automated mfiri brushing anaasɛ localized induction ɔhyew ansa na welding station. Nea ɛne eyi bɔ abira no, amanne kwan so fabrication wɔ biako so galvanized dade krataa taa ma nsaano flap-disc grinding yɛ nea ɛho ka sua na mfaso wɔ so sen biara.
Welding Adeyɛ Nhwehwɛmu ma Galvanized Nneɛma
Sɛ woyi ade a wɔde kata so no fi hɔ pɛpɛɛpɛ a, ɛntaa mma sɛ wobetumi ayɛ wɔ afuw mu tebea horow mu. Mpɛn pii no, zinc a wɔde microscopic trace trace no kɔ so tra hɔ. Enti, ɛsɛ sɛ wopaw welding kwan a ebetumi agyina efĩ nketenkete ano.
Welding Adeyɛ a Wɔyɛ |
Trace Zinc Tolerance a Ɛwɔ Hɔ |
Nneɛma a Wɔde Di Dwuma a Wɔkamfo Kyerɛ |
Dwumadie a Ɛfata |
FCAW (Flux-Cored) a wɔde yɛ adwuma . |
Soro |
Wire a ɛwɔ kyɛm abien anaa nea ɛbɔ ne ho ban |
Ɔdansi a emu yɛ duru, abɔnten afuw mu adwuma |
SMAW (Poma) . |
Soro |
E7018 electrode ahorow a hydrogen sua |
Maintenance, afã horow a ɛyɛ den |
GMAW (MIG) na ɛyɛ adwuma. |
Kakra |
ER70S-6 nhama a ɛyɛ den |
Nneɛma a wɔyɛ no ntɛmntɛm, nkratafa a ɛyɛ tratraa |
GTAW (TIG) na ɛyɛ . |
Ohunu |
N/A |
Abam abu kɛse |
FCAW (Flux-Cored) & SMAW (Stick): Saa akwan yi da abodwokyɛre kɛse adi ma trace zinc. Nneɛma a ɛma nsu fa nsu mu a wɔde ahyɛ electrode ahorow no mu no yɛ nwini ntɛmntɛm wɔ ɔtare a ayɛ hyew no mu. Wɔde nsiyɛ yi atɛkyɛ no mu, na wɔma efĩ ne mframa a wɔakyere no so kɔ slag a ɛwɔ mu no mu. Wɔ SMAW adwumayɛ ho no, mfiridwumayɛfo kamfo E7018 electrodes a hydrogen sua kyerɛ kɛse. Wɔyɛ welds a ɛyɛ den na ɛyɛ ductile bere mpo a nneɛma nketenkete a wɔde kata so no da so ara wɔ hɔ no.
GMAW (MIG): Solid wire MIG ma ahoɔhare a ɛkyɛn so a wɔyɛ. Ɛyɛ adwuma yiye titiriw wɔ thin so galvanized dade krataa nhyiam ahorow. Nanso, MIG nni nneɛma a ɛma nsu no yɛ adwuma. Ɛhwehwɛ sɛ wɔhwɛ parameter so denneennen. Ɛsɛ sɛ wode akwan a wɔfa so de ɔhyew a ɛba fam te sɛ short-circuit anaa pulsed-spray transfer di dwuma. Bere nyinaa fa ER70S-6 waya di dwuma. Silicon ne manganese a wɔde aka ho wɔ ER70S-6 mu no yɛ adwuma sɛ deoxidizers, na ɛboa ma bead no yɛ petee na ɛko tia emu porosity.
GTAW (TIG) – The Exclusion Zone: Field osuahu di adanse sɛ TIG yɛ n’ade te sɛ dae bɔne wɔ saa nneɛma yi so. Tungsten electrode a ɛnyɛ nea wɔde di dwuma no hwehwɛ sɛ ɛho tew koraa. Ɛbɛyɛ nea efĩ wom ntɛm ara denam zinc ketewaa biara a wɔpa bere a wɔresiesie no so. Arc no bɛteɛteɛm, akɔkyinkyin, na awiei koraa no adum. Yi TIG fi wo dwumadi ahorow mu koraa gye sɛ woyɛ adwuma wɔ dade a ɛda hɔ kwa a wɔagye atom 100% so.
Joint Quality Assurance ne Post-Weld Sanba
Wɔn a wɔyɛ nneɛma pii haw wɔn ho wɔ sɛnea wobetumi de wɔn ho ato saa nhyiam ahorow yi so bere tenten no ho. Wogye akyinnye sɛ ebia nneɛma no su sɛe wɔ ɔhyew kyinhyia no mu anaa.
Amanaman Ntam Lead Zinc Nhwehwɛmu Ahyehyɛde (ILZRO) yɛɛ nipadua mu nhwehwɛmu kɛse wɔ saa nkwaa yi ho. Mfiri a ɛwɔ mu no da so ara yɛ nea ɛte saa koraa. ILZRO data di adanse sɛ welded yiye galvanized nkwaa da tensile ahoɔden a ɛyɛ pɛ, bend radii, ne impact adwumayɛ sɛ wɔde toto uncoated dade nhyiam ahorow.
Nanso, micro-porosity nketenkete taa kɔ so tra hɔ. Wubetumi de mfiridwuma ho akwan a nyansa wom atua porosity fatigue no ka. Wɔ nkwaa a wɔde ahyɛ adesoa a ɛho hia a ɛma ɔbrɛ a ɛyɛ kyinhyia ase no, mfiridwumayɛfo taa kyerɛ 'oversized welds.' Fillet weld kɛse a wɔma ɛkɔ soro kakra no siw volume a ɛyera esiane micro-porosity nti no ano yiye. Saa nipadua mu ntrɛwmu yi brɛ adwennwen a ɛwɔ nipadua no mu nyinaa ase. Ɛmma zinc penetrator intergranular mpaapaemu ntumi nkɔ ntini no mu.
Awiei koraa no, grinding ne welding sɛe afɔrebɔ akwanside no. Ɛsɛ sɛ wode ahobammɔ a ɛbɔ wɔ weld akyi no di dwuma na amma wim nsɛe ntɛmntɛm. Kyerɛ sɛnea wodi ASTM A780 gyinapɛn a wɔde san de ahobammɔ layer no ba no so katee.
Kyerɛ sɛnea wɔde paint a zinc wom, a wɔtaa frɛ no cold galvanizing spray bedi dwuma. Fa eyi gu HAZ ne asase so mmeae nyinaa so kɛse. Hwɛ sɛ dry film no mu duru ne hot-dip layer a atwa ho ahyia no hyia. Wɔ ɔdan no mufo akɛse fam no, thermal metallizing (zinc spraying) ma wonya nkitahodi a ɛkorɔn, a ɛte sɛ adwumayɛbea. ASTM A780 akyi no hwɛ hu sɛ welded joint foforo no nya lifecycle parity ka mfitiase hot-dip coating no ho.
Awie
Welding saa ahobammɔ alloys yi yɛ koraa viable ma structure ne mfiridwuma applications. Ɛsɛ sɛ wobɛn no sɛ ɔkwan a wɔahyɛ so denneennen sen sɛ wobɛfa ɔkwan tiawa a wɔfa so weld tẽẽ. Ahosiesie anammɔn a wohuruw no ma ɔdan mu nokwaredi ne nnipa ahobammɔ nyinaa to asiane mu. Sɛ wogye bere yi nkwaa no fi hɔ a, ɛma wotumi hyɛn mu kɔ akyiri, ɛyɛ arcs a ɛyɛ den, na mfiri no yɛ adwuma yiye.
Sɛnea ɛbɛyɛ a nea ebefi wo fabrication mu aba no atu mpɔn no, fa anammɔn a edi hɔ yi ntɛm ara:
Hwɛ wo mprempren localized fume extraction infrastructure no mu na ama woahwɛ ahu sɛ wobɛkyere ahoɔhare a ɛfata.
Yɛ wo WPS (Welding Procedure Specifications) no foforo ma ɛda zinc a woyi fi hɔ a ɛyɛ nsateakwaa 1 kosi 4 no adi pefee.
Standardize wo post-weld touch-up consumables ma ɛne ASTM A780 dry film thickness ahwehwɛde ahorow hyia pɛpɛɛpɛ.
Transition sensitive applications away from TIG na fa dual-shield FCAW anaa pulsed MIG di dwuma ma efĩ a wotumi gyina ano yiye.
FAQ
Asɛmmisa: So dade a wɔde galvanized ayɛ a wɔde weld yɛ no ma dade no yɛ mmerɛw?
A: Dabi Sɛ wɔasiesie no yiye a, ahoɔden a ɛtwetwe ne sɛnea ɛyɛ den sɛ ɛbɛpaapae no da so ara yɛ pɛ ne dade a wɔankata so. Sɛ woyi zinc a ɛwɔ soro no fi hɔ ansa na woabɔ arc no a, ɛma wotumi hyɛn mu yiye na esiw ɔdan no mu sintɔ akɛse ano.
Asɛmmisa: So metumi anom nufusu de asiw dade wusiw atiridii ano?
A: Ɛnyɛ saa koraa. Nufusu mma ɔhome ho ahobammɔ biara. Ɛkɔ aduan mu, na ɛmma w’ahurututu no ahobammɔ biara. Fibea a woyi fi mu ne PPE a ɛfata (te sɛ P100 afiri a wɔde home) nkutoo na esiw zinc oxide a asiane wom ano.
Asɛmmisa: So metumi de TIG ayɛ dade a wɔde galvanized ayɛ no weld?
A: Ɛyɛ abasamtu kɛse. TIG hwehwɛ sɛ wonya baabi a ɛho tew soronko. Zinc nkae a wɔde hwɛ nneɛma nketenkete mpo a wobegyaw bere a wɔayam no denneennen akyi no bɛgu tungsten electrode no ho fĩ kɛse, na ama arc no akɔkyinkyin, ateɛteɛm, na awiei koraa no adi nkogu.
Asɛmmisa: Ɛhe na ɛsɛ sɛ meyam galvanizing no ansa na mayɛ welding?
A: Nnwuma gyinapɛn (te sɛ AWS D-19.0) kyerɛ sɛ wobeyi nsateakwaa 1 kosi 4 afi weld beae no. Saa buffer a ɛho hia yi mma ɔhyew a atwa yɛn ho ahyia no ntumi mma zinc a atwa ho ahyia no ntumi ntwe nkɔ weld pool a ayɛ hyew no mu.
