Ukushisela insimbi engagqwali kudinga ukukhethwa kwegesi yokuvikela ukuze kulondolozwe ukwakheka kwayo kwensimbi kanye nezakhiwo zayo zomzimba nezomshini ezihambisanayo. Izakhi zegesi zokuvikela ezivamile zensimbi engagqwali zifaka i-argon, i-helium, i-oxygen, i-carbon dioxide, i-nitrogen, ne-hydrogen (bheka uMfanekiso 1). Lawa magesi ahlanganiswa ngezilinganiso ezahlukene ukuze avumelane nezidingo zezindlela ezahlukene zokulethwa, izinhlobo zocingo, ama-alloy esisekelo, iphrofayili yobuhlalu obufunwayo kanye nesivinini sokuhamba.
Ngenxa yokuguquguquka kokushisa kwensimbi engagqwali kanye nohlobo "olubandayo" lokushisela i-arc yensimbi yegesi yokudlulisa i-short-circuit (GMAW), inqubo idinga igesi "exutshwe kathathu" equkethe i-helium engu-85% kuya ku-90% (He), kufika ku-10% Argon (Ar) kanye ne-Carbon Dioxide engu-2% kuya ku-5% (CO2). Ingxube evamile ye-triblend iqukethe i-90% He, i-7-1/2% Ar, kanye ne-2-1/2% CO2. Amandla aphezulu e-ionization e-helium akhuthaza i-arcing ngemva kwe-short circuit; kanye ne-conduction yayo ephezulu yokushisa, ukusetshenziswa kwe-He kwandisa ukugeleza kwechibi elincibilikisiwe. Ingxenye ye-Ar ye-Trimix inikeza ukuvikelwa okujwayelekile kwe-weld puddle, kuyilapho i-CO2 isebenza njengengxenye esabelayo ukuze kuzinziswe i-arc (bheka uMfanekiso 2 ukuze uthole ukuthi amagesi okuvikela ahlukene athinta kanjani iphrofayili ye-weld bead).
Ezinye izingxube ze-ternary zingasebenzisa i-oxygen njengesiqinisi, kanti ezinye zisebenzisa ingxube ye-He/CO2/N2 ukuze kufezwe umphumela ofanayo. Abanye abasabalalisi begesi banezingxube zegesi ezizimele ezinikeza izinzuzo ezithembisiwe. Abathengisi batusa futhi lezi zingxube kwezinye izindlela zokudlulisa ezinomphumela ofanayo.
Iphutha elikhulu elenziwa abakhiqizi ukuzama ukufinyeza insimbi engagqwali ye-GMAW ngengxube efanayo yegesi (75 Ar/25 CO2) njengensimbi ethambile, ngokuvamile ngoba abafuni ukuphatha isilinda esengeziwe. Le ngxube iqukethe ikhabhoni eningi kakhulu. Eqinisweni, noma iyiphi igesi yokuvikela esetshenziselwa ucingo oluqinile kufanele iqukathe ubuningi bekhabhoni dioxide engu-5%. Ukusebenzisa amanani amakhulu kuholela ekusetshenzisweni kwensimbi okungasabhekwa njenge-alloy yebanga le-L (ibanga le-L linokuqukethwe kwekhabhoni okungaphansi kuka-0.03%). Ikhabhoni eningi kakhulu kugesi yokuvikela ingakha ama-carbide e-chromium, anciphisa ukumelana nokugqwala kanye nezakhiwo zemishini. I-soot ingavela futhi ebusweni be-weld.
Njengenothi eliseceleni, lapho kukhethwa izinsimbi zokunciphisa i-GMAW yama-alloy esisekelo angu-300 (308, 309, 316, 347), abakhiqizi kufanele bakhethe izinga le-LSi. Ama-filler e-LSi anokuqukethwe okuphansi kwekhabhoni (0.02%) futhi ngenxa yalokho anconywa kakhulu lapho kunengozi yokugqwala kwe-intergranular. Okuqukethwe okuphezulu kwe-silicon kuthuthukisa izakhiwo ze-weld, njengokumanzisa, ukusiza ukuthambisa umqhele we-weld nokukhuthaza ukuhlangana ozwaneni.
Abakhiqizi kufanele baqaphele lapho besebenzisa izinqubo zokudlulisa ze-short-circuit. Ukuhlanganiswa okungaphelele kungabangelwa ukucisha kwe-arc, okwenza inqubo ingabi ngcono kakhulu ekusetshenzisweni okubalulekile. Ezimweni zomthamo ophezulu, uma impahla ingasekela okokufaka kwayo ukushisa (≥ 1/16 intshi cishe iyinto encane kakhulu ehlanganisiwe kusetshenziswa imodi yokufutha kwe-pulse), ukudluliselwa kwe-pulse spray kuzoba yisinqumo esingcono. Lapho ubukhulu bezinto nendawo yokufutha kuyisekela, ukudluliselwa kwe-spray GMAW kuyathandwa njengoba kunikeza ukuhlanganiswa okuhlala njalo.
Lezi zindlela zokudlulisa ukushisa okuphezulu azidingi igesi yokuvikela. Ukuze kufakwe ukushiswa kokudluliselwa kokufutha kwama-alloy angu-300 ochungechunge, ukukhetha okuvamile yi-98% Ar kanye ne-2% yezinto ezisebenzayo njenge-CO2 noma i-O2. Ezinye izingxube zegesi zingase ziqukathe inani elincane le-N2. I-N2 inamandla aphezulu e-ionization kanye nokuqhuba ukushisa, okukhuthaza ukumanzisa futhi kuvumela ukuhamba okusheshayo noma ukugeleza okuthuthukisiwe; futhi kunciphisa ukuphambuka.
Ngokudluliselwa kwe-pulsed spray GMAW, i-100% Ar ingaba yisinqumo esamukelekayo. Ngenxa yokuthi i-pulsed current izinzisa i-arc, igesi ayidingi njalo izinto ezisebenzayo.
Ichibi elincibilikisiwe lihamba kancane ngezinsimbi ezingagqwali ze-ferritic kanye nezinsimbi ezingagqwali ezimbili (isilinganiso esingu-50/50 se-ferrite ne-austenite). Kulezi zinsimbi, ingxube yegesi efana ne-~70% Ar/~30% He/2% CO2 izokhuthaza ukumanzisa okungcono futhi inyuse isivinini sokuhamba (bheka Umfanekiso 3). Izingxube ezifanayo zingasetshenziswa ukushisela ama-alloy e-nickel, kodwa zizobangela ukuthi kwakheke ama-nickel oxides ebusweni bokushisela (isb., ukwengeza i-2% CO2 noma i-O2 kwanele ukwandisa okuqukethwe kwe-oxide, ngakho abakhiqizi kufanele bawagweme noma balungele ukuchitha isikhathi esiningi kuwo). Aqinile ngoba la ma-oxide aqinile kangangokuthi ibhulashi lensimbi ngokuvamile ngeke liwasuse).
Abakhiqizi basebenzisa izintambo zensimbi engagqwali ezine-flux-core zokushisela ngaphandle kwe-situ ngoba uhlelo lwe-slag kulezi zintambo lunikeza "ishelufu" elisekela ichibi lokushisela njengoba liqina. Ngenxa yokuthi ukwakheka kwe-flux kunciphisa imiphumela ye-CO2, intambo yensimbi engagqwali ene-flux-core yenzelwe ukusetshenziswa ngezingxube zegesi ze-75% Ar/25% CO2 kanye/noma i-100% CO2. Ngenkathi intambo ene-flux-core ingabiza kakhulu ngephawundi, kubalulekile ukuqaphela ukuthi isivinini esiphezulu sokushisela kuzo zonke izindawo kanye namazinga okufaka kunganciphisa izindleko zokushisela ezijwayelekile. Ngaphezu kwalokho, intambo ene-flux-core isebenzisa ukuphuma kwe-DC voltage evamile, okwenza uhlelo lokushisela oluyisisekelo lungabizi kakhulu futhi lungabi yinkimbinkimbi kunezinhlelo ze-GMAW eziqhutshwa yi-pulsed.
Kuma-alloy ochungechunge angu-300 no-400, i-100% Ar isalokhu iyisinqumo esijwayelekile sokushisela i-arc ye-tungsten yegesi (i-GTAW). Ngesikhathi se-GTAW yama-alloy e-nickel, ikakhulukazi ngezinqubo ezenziwe ngomshini, inani elincane le-hydrogen (kufika ku-5%) lingangezwa ukwandisa isivinini sokuhamba (qaphela ukuthi ngokungafani nezinsimbi zekhabhoni, ama-alloy e-nickel awakwazi ukuqhekeka nge-hydrogen).
Ngokushisela izinsimbi ezingagqwali ze-superduplex kanye ne-superduplex, i-98% Ar/2% N2 kanye ne-98% Ar/3% N2 ziyizinketho ezinhle, ngokulandelana. I-Helium ingangezwa futhi ukuthuthukisa ukumanzi cishe ngo-30%. Lapho kushiselwa izinsimbi ezingagqwali ze-super duplex noma ze-super duplex, umgomo ukukhiqiza ijoyinti elinesakhiwo esincane esilinganiselayo esingaba ngu-50% we-ferrite kanye no-50% we-austenite. Ngoba ukwakheka kwesakhiwo esincane kuncike esilinganisweni sokupholisa, futhi ngenxa yokuthi ichibi le-TIG weld liphola ngokushesha, i-ferrite eyengeziwe ihlala lapho kusetshenziswa i-100% Ar. Lapho kusetshenziswa ingxube yegesi equkethe i-N2, i-N2 ixuba echibini elincibilikisiwe futhi ikhuthaze ukwakheka kwe-austenite.
Insimbi engagqwali idinga ukuvikela izinhlangothi zombili zejoyinti ukuze ikhiqize i-weld eqediwe enokumelana okukhulu nokugqwala. Ukwehluleka ukuvikela ingemuva kungabangela "ukungagqwali," noma ukungcoliswa okukhulu okungaholela ekwehlulekeni kwe-solder.
Izithako eziqinile ezinezinga elifanele kahle noma ukugcinwa okuqinile ngemuva kwethako kungenzeka zingadingi igesi yokusekela. Lapha, inkinga enkulu ukuvimbela ukushintsha kombala okweqile kwendawo ethintekile ekushiseni ngenxa yokwakheka kwe-oxide, okudinga ukususwa ngomshini. Ngobuchwepheshe, uma izinga lokushisa langemuva lidlula ama-degrees Fahrenheit angu-500, kudingeka igesi yokuvikela. Kodwa-ke, indlela elondolozayo ukusebenzisa ama-degrees Fahrenheit angu-300 njengomkhawulo. Okungcono kakhulu, i-backback kufanele ibe ngaphansi kwama-30 PPM O2. Okuhlukile ukuthi i-backback ye-weld izogezwa, igaywe futhi ihlanganiswe ukuze kufezwe i-weld egcwele.
Amagesi amabili asekelayo akhethwayo yi-N2 (eshibhile kakhulu) kanye ne-Ar (ebiza kakhulu). Ezihlanganisweni ezincane noma lapho imithombo ye-Ar itholakala kalula, kungaba lula kakhulu ukusebenzisa le gesi futhi akufanele ukonge i-N2. Kungangezwa i-hydrogen efinyelela ku-5% ukunciphisa i-oxidation. Kunezinketho eziningi zokuhweba ezitholakalayo, kodwa izisekelo ezenziwe ekhaya kanye namadamu okuhlanza avamile.
Ukwengezwa kwe-10.5% noma ngaphezulu kwe-chromium yikho okwenza insimbi engagqwali ibe nezakhiwo zayo ezingagqwali. Ukugcina lezi zakhiwo kudinga ubuchwepheshe obuhle ekukhetheni igesi yokuvikela ukushisela efanele nokuvikela ingemuva lejoyinti. Insimbi engagqwali iyabiza, futhi kunezizathu ezinhle zokuyisebenzisa. Akunangqondo ukuzama ukunciphisa amakhona uma kukhulunywa ngegesi yokuvikela noma ukukhetha izinsimbi zokugcwalisa lokhu. Ngakho-ke, kuhlale kunengqondo ukusebenza nomsabalalisi wegesi onolwazi kanye nochwepheshe wensimbi yokugcwalisa lapho ukhetha insimbi yegesi neyokugcwalisa yokushisela insimbi engagqwali.
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