Ukukhetha igesi efanelekileyo kwimizi-mveliso ayikho nje into yokukhetha isilinda; sisigqibo esibalulekileyo esichaphazela umgangatho, ukusebenza kakuhle, kunye nokhuseleko lwe-welding yakho kunye nokusebenza kokusika. Irhasi efanelekileyo yokukhusela ikhusela i-weld pool etyhidiweyo ekungcoleni kwe-atmospheric, ngelixa i-gas yokusika efanelekileyo iqinisekisa ukucoca, ukusika okuchanekileyo. Esi sikhokelo sibanzi siya kukuhamba kwizinto ezibalulekileyo ekufuneka uziqwalasele xa ukhetha iigesi zemizi-mveliso, ukuqinisekisa ukuba ufikelela kwiziphumo ezizezona zilungileyo kwizicelo zakho ezithile.

Ukuqonda iiGesi zokuKhusela ukuWelding

Iigesi ezikhuselayo ziyimfuneko kwiinkqubo ezifana neGas Metal Arc Welding (GMAW/MIG) kunye neGas Tungsten Arc Welding (GTAW/TIG). Owona msebenzi wabo uphambili kukususa iigesi ezisemoyeni—ioksijini nenitrogen—kwindawo yokutshisa. Ukuba ezi gesi ze-atmospheric zingena kwi-weld pool etyhidiweyo, zinokubangela i-porosity (imingxuma kwi-weld), ukuqina, kunye nenkangeleko ye-weld embi.

Ukukhetha igesi ekhuselayo kuchaphazela kakhulu imiba ephambili yenkqubo yokuwelda:

• Uzinzo lweArc: Ezinye iigesi zikhuthaza i-arc egudileyo, ezinzileyo, ukunciphisa i-spatter kunye nokwenza inkqubo ibe lula ukuyilawula.

• Ukungena kweWeld: Ukubunjwa kwegesi kuchaphazela indlela ubushushu obunzulu bungena ngayo kwisiseko sesinyithi, ukuchaphazela amandla okudibanisa.

• Inkangeleko yeWeld: Ubume be-weld bead (umzekelo, i-flat, i-convex, okanye i-concave) inqunywe ngokuyinxenye yigesi yokukhusela.

• Iinkcazelo ngoomatshini: Irhasi inokuchaphazela amandla okugqibela, i-ductility, kunye nokunganyangeki kwe-corrosion ye-weld metal.

• Inqanaba leSpatter: Imixube ethile yerhasi inciphisa isitshizi, inciphisa ixesha lokucoca emva kweweld.

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Iigesi eziqhelekileyo zoShishino ezisetyenziswa kwi-Welding

Okuninzi iigesi ezisetyenziswa rhoqo kwimizi-mveliso I-welding iwela kwiindidi ezimbalwa eziphambili, nganye inika iimpawu ezahlukileyo.

Argon (i-AR)

IArgon lihashe lomsebenzi wokukhusela iigesi. Yigesi engasebenziyo, okuthetha ukuba ayisebenzi ngokwekhemikhali ngesinyithi esinyibilikisiweyo.

• Usetyenziso: IArgon lukhetho oluqhelekileyo lwe-GTAW (TIG) yokuwelda uninzi lwesinyithi, ngakumbi i-aluminiyam, i-magnesium, kunye ne-titanium. Inika uzinzo olugqwesileyo lwe-arc kunye nembonakalo ye-weld ecocekileyo.

• Iimpawu: Ivelisa iprofayili yokungena emxinwa, enzulu. Kuba inzima kunomoya, ibonelela ngokhuselo olugqwesileyo phezu kwechibi le-weld, ngakumbi kwiindawo zokuwelda ezisicaba.

Helium (yena)

I-Helium yenye igesi ye-inert, kodwa iziphatha ngendlela ehluke kakhulu kwi-argon.

• Usetyenziso: Ihlala isetyenziswa ngokudityaniswa ne-argon yokuwelda imathiriyeli etyebileyo okanye iintsimbi ezine-conductivity ephezulu ye-thermal, njenge-aluminiyam kunye nobhedu.

• Iimpawu: I-Helium ivelisa i-arc eshushu kune-argon, ebangela ukungena okubanzi, okunzulu kunye nesantya sokuhamba ngokukhawuleza. Nangona kunjalo, ilula kunomoya, ifuna amazinga aphezulu okuhamba ukuze kugcinwe ukukhuselwa okwaneleyo, kwaye inokwenza ukuqala kwe-arc kube nzima ngakumbi.

ICarbon Dioxide (CO2)

Ngokungafani ne-argon kunye ne-helium, i-carbon dioxide yigesi esebenzayo. Ngaphantsi kobushushu obukhulu be-arc ye-welding, ihlahlela kwi-carbon monoxide kunye ne-oxygen.

• Usetyenziso: I-CO2 isetyenziswa ngokubanzi kwi-GMAW (MIG) ye-welding ye-carbon steel. Idla ngokuba lolona khetho lunoqoqosho.

• Iimpawu: Ibonelela ngokungena okunzulu kodwa ithande ukuvelisa i-arc engazinzanga kwaye i-spatter engaphezulu kune-inert gases okanye imixube ye-argon. Iprofayile ye-weld ephumayo ihlala ibanzi kwaye i-oxidized ngakumbi.

Ioksijini (O2)

Ioksijini iyasebenza kakhulu kwaye ayikaze isetyenziswe njengegesi ekhuselayo iyodwa.

• Usetyenziso: Izixa ezincinci ze-oksijini (ngokuqhelekileyo i-1-5%) zivame ukufakwa kwi-argon ye-welding carbon kunye ne-low-alloy steels, kwaye ngamanye amaxesha insimbi engenasici.

• Iimpawu: Ioksijini iphucula uzinzo lwe-arc, inciphisa ukuxinana komphezulu wesinyithi esinyibilikisiweyo (ivumela ukuba iphume kakuhle), kwaye inokuphucula ukungena kwizicelo ezithile.

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Ukukhetha iigesi kwiiNkqubo eziKhethekileyo zeWelding

Ukhetho olufanelekileyo lwegesi luxhomekeke kakhulu kwinkqubo ye-welding kunye nesiseko sezinto.

IGas Metal Arc Welding (GMAW / MIG)

Ukuwelda kwe-MIG kuxhomekeke kakhulu kwimixube yerhasi eyenzelwe intsimbi ethile.

• Intsimbi yeCarbon:

  • 100% CO2: Olona khetho lubiza kakhulu, lunikezela ukungena okunzulu kodwa ukutshiza okuphezulu. Ilungile kwizinto ezityebileyo.

  • Argon/CO2 Imixube (umzekelo, 75% Ar / 25% CO2 okanye "C25"): Olona khetho luqhelekileyo kwimveliso jikelele. Babonelela ngolungelelwaniso lokuzinza kwe-arc elungileyo, i-spatter esezantsi kune-CO2 ecocekileyo, kunye nembonakalo entle kakhulu ye-weld bead. Iipesenti ezisezantsi ze-CO2 (umzekelo, i-5-15%) zisetyenziselwa izinto ezincinci okanye i-pulsed MIG welding.

  • Imixube yeArgon/Oxygen (umzekelo, 95% Ar / 5% O2): Isetyenziselwa ukutshiza ukuwelda kwentsimbi yekhabhoni, ivelisa ichibi leweld elimanzi kakhulu kunye nokungena nzulu.

• Intsimbi engatyiwa:

  • Argon/CO2 (umzekelo, 98% Ar / 2% CO2): Ukhetho oluqhelekileyo, kodwa umxholo we-CO2 kufuneka ugcinwe uphantsi ukuze unciphise i-carbon pickup, enokunciphisa ukuxhathisa kwe-corrosion.

  • Imixube ye-Tri-(Argon/Helium/CO2): Ihlala isetyenziselwa ukuwelda i-short-circuit yentsimbi ebhityileyo engenasici, ebonelela ngeempawu ezibalaseleyo ze-arc kunye nokunciphisa ukugqwetheka.

• Aluminiyam:

  • 100% Argon: Ukhetho olusemgangathweni uninzi lwe-MIG welding ye-aluminium ukuya kuthi ga malunga ne-1/2 intshi ubukhulu.

  • Argon / Helium Imixube (umzekelo, 50% Ar / 50% Yena okanye 25% Ar / 75% Yena): Isetyenziselwa amacandelo e-aluminiyam angqindilili ukunyusa igalelo lobushushu kunye nokungena.

Irhasi yeTungsten Arc Welding (GTAW / TIG)

I-TIG welding ngokubanzi idinga iigesi ezingenayo ukukhusela i-electrode ye-tungsten engasetyenziswanga kunye ne-weld pool.

• Zonke iintsimbi (ngaphandle kwamacandelo ashinyene kakhulu): I-100% iArgon lukhetho lwendalo yonke, inika i-arc egqwesileyo yokuqala, ukuzinza, kunye nesenzo sokucoca (ibaluleke kakhulu kwi-aluminium).

• IAluminiyam okanye ubhedu: Imixube yeArgon / Helium (ihlala i-50/50 okanye i-75/25 Helium/Argon) isetyenziselwa ukunyusa i-arc voltage kunye negalelo lobushushu, ivumela ukungena nzulu kunye nokuhamba ngokukhawuleza kwezantya kwizinto eziqhuba kakhulu.

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Ukukhetha iigesi kwiiNkqubo zokusika

Iinkqubo zokusika zifuna iirhasi ukuba ziphembe ilangatye, zivuthele isinyithi esinyibilikisiweyo, okanye zombini.

I-Oxy-Fuel Cutting

Le nkqubo isebenzisa irhasi yamafutha exutywe neoksijini esulungekileyo ukutshisa intsimbi kwiqondo lobushushu bayo, emva koko i-oksijini yoxinzelelo oluphezulu isetyenziselwa ukukhawuleza i-oxidize (ukutshisa) kunye nokuvuthela isinyithi. Ukukhethwa kwerhasi yamafutha kuchaphazela kakhulu isantya sokusika kunye nomgangatho.

• Iacetylene: Ivelisa elona qondo lobushushu liphezulu kunayo nayiphi na irhasi yamafutha eqhelekileyo, ivumela awona maxesha akhawulezayo obushushu bangaphambi kwexesha. Igqwesile kwi-beveling kunye nokugqobhoza kodwa ifuna ukuphathwa ngononophelo ngenxa yokungazinzi kwayo kuxinzelelo oluphezulu.

• Ipropane: Ukhetho olunoqoqosho kakhulu, olusetyenziselwa ukusika ngokubanzi kunye nokufudumeza. Inobushushu obusezantsi bedangatye kune-acetylene, ikhokelela kumaxesha amade kancinane obushushu, kodwa ikhuselekile ukuyigcina nokuyihambisa.

• Ipropylene: Inika ubushushu bomlilo phakathi kwepropane kunye ne-acetylene. Inika amaxesha okukhawuleza okutshisa kune-propane kwaye idla ngokukhethwa kwizicelo zokusika ezinzima.

• Irhasi yendalo: Ngokuqhelekileyo eyona ndlela ingabizi kakhulu ukuba ifakwe ngqo kwiziko. Inokushisa okuphantsi komlilo, okwenza ukuba ifaneleke kakhulu kwizinto ezincinci okanye izicelo apho ixesha lokutshisa kwangaphambili lingeyona nto ibalulekileyo.

Ukusika i-Plasma Arc

Ukusika kwe-plasma kusebenzisa i-jet yesantya esiphezulu segesi ye-ionized (i-plasma) ukunyibilika kunye nokuqhawula isinyithi.

• Umoya (Umoya oxiniweyo): Olona khetho luqhelekileyo kunye noqoqosho lwenjongo yokusika i-carbon steel, insimbi engenasici, kunye ne-aluminium. Ifuna umoya ococekileyo, owomileyo, nongenaoyile.

• I-nitrogen: Ihlala isetyenziselwa ukusika intsimbi engatyiwayo kunye nealuminiyam, njengoko ivelisa umphetho ococekileyo oneoxidation encinci xa kuthelekiswa nomoya oxinanisiweyo. Ikwasetyenziswa rhoqo njengegesi yesibini (ikhaka) kwiinkqubo zegesi ezimbini.

• Ioksijini: Ibonelela ngezantya ezikhawulezayo zokusika kunye nemiphetho ecocekileyo kwi-carbon steel, kodwa ayikhuthazwa kwintsimbi engenasici okanye i-aluminium.

• Imixube yeArgon/Hydrogen (umzekelo, H35 - 65% Ar / 35% H2): Isetyenziselwa ukusika intsimbi eshinyeneyo kakhulu kunye ne-aluminiyam. Ihydrogen ibonelela ngokugqithiselwa kobushushu okuphezulu, okukhokelela kumgangatho ogqwesileyo wokusika kunye nezantya ezikhawulezayo kwizinto ezinzima.

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IMatrix yoKhetho lwegesi

Ukwenza lula inkqubo yokhetho, jonga kwesi sikhokelo sikhawulezayo:

IiNgqwalaselo zoMgangatho noBunyulu

Ukucoceka kwerhasi yeshishini lakho kubaluleke kakhulu. Izinto ezingcolisayo ezifana nokufuma, ioksijini (kwizicelo zerhasi engasebenziyo), okanye iihydrocarbons zinokuwuthoba kakhulu umgangatho weweld, zibangele iporosity, brittleness, kunye nenkangeleko engalunganga.

• Iigesi zeBanga lokuWelding: Ngalo lonke ixesha qinisekisa ukuba usebenzisa iigesi eziqinisekisiweyo njenge "welding grade," enemigangatho ephezulu yokucoceka (umzekelo, i-99.99% okanye ngaphezulu kwi-argon).

• Ukuphathwa kweCylinder: Ukugcinwa ngokufanelekileyo kunye nokuphathwa kweesilinda kubalulekile ukugcina ukucoceka kwegesi. Gcina iivalvu zivaliwe xa zingasetyenziswa kwaye uphephe ukubeka iisilinda kumaqondo obushushu agqithisileyo.

• Iinkqubo zokuhanjiswa: Qinisekisa ukuba izilawuli zakho, imibhobho, kunye neeflowutmeters zicocekile, azivuzi, kwaye ziyilelwe irhasi ethile esetyenziswayo.

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Ukuqukumbela

Ukukhetha i igesi yamashishini ekunene I-welding kunye nokusika linyathelo elibalulekileyo ekuphumezeni umgangatho ophezulu, osebenzayo, kunye neziphumo ezingabizi kakhulu. Ngokuqonda iipropathi zeegesi ezikhuselayo ezahlukeneyo kunye neegesi zokusika, kwaye uzifanise neenkqubo zakho ezithile kunye nezixhobo, unokwandisa ukusebenza kwakho kwaye uqinisekise ukuthembeka komsebenzi wakho. Ungalibazisi ukubonisana nomthengisi wakho wegesi okanye umenzi wezixhobo ze-welding ukuze ufumane iingcebiso ezihambelana neemfuno zakho zesicelo.