Insimbi engagqwali akunzima ngempela ukuyisebenzisa, kodwa ukuyifaka kudinga ukunakwa ngokucophelela emininingwaneni. Ayisusi ukushisa njengensimbi encane noma i-aluminium, futhi ingase ilahlekelwe ukumelana nokugqwala uma ufaka ukushisa okuningi kuyo. Imikhuba emihle isiza ekugcineni ukumelana kwayo nokugqwala. Isithombe: Miller Electric
Ukumelana nokugqwala kwensimbi engagqwali kwenza kube ukukhetha okukhangayo kwezicelo eziningi ezibalulekile zamapayipi, okuhlanganisa ukudla neziphuzo ezihlanzekile kakhulu, imithi, imithambo yokucindezela, kanye nezicelo ze-petrochemical. Kodwa-ke, lokhu akususi ukushisa njengensimbi encane noma i-aluminium, futhi ukushisela okungafanele kunganciphisa ukumelana kwayo nokugqwala. Ukusebenzisa ukushisa okuningi kakhulu nokusebenzisa insimbi yokugcwalisa engalungile kuyizinto ezimbili eziyimbangela.
Ukulandela eminye imikhuba emihle kakhulu yokushisela insimbi engagqwali kungasiza ekuthuthukiseni imiphumela nokuqinisekisa ukuthi insimbi igcina ukumelana kwayo nokugqwala. Ngaphezu kwalokho, ukuthuthukisa inqubo yokushisela kungaletha izinzuzo zokukhiqiza ngaphandle kokubeka engcupheni ikhwalithi.
Ekushiseni ngensimbi engagqwali, ukukhetha insimbi yokugcwalisa kubalulekile ekulawuleni okuqukethwe yikhabhoni. Izinsimbi zokugcwalisa ezisetshenziselwa ukushiseni ngamapayipi ensimbi engagqwali kufanele zithuthukise ukusebenza kokushise futhi zihlangabezane nezidingo zohlelo lokusebenza.
Funa izinsimbi zokugcwalisa ezinegama elithi “L”, njenge-ER308L, njengoba zinikeza okuqukethwe okuphansi kakhulu kwekhabhoni okusiza ukugcina ukumelana nokugqwala kwezinsimbi zensimbi ezingagqwali ezinekhabhoni ephansi. Ukushisela insimbi eyisisekelo enekhabhoni ephansi ngezinsimbi zokugcwalisa ezijwayelekile kwandisa okuqukethwe kwekhabhoni kwejoyinti elishisiwe, okwandisa ingozi yokugqwala. Gwema izinsimbi zokugcwalisa eziphawulwe ngo-“H” njengoba lezi zinikeza okuqukethwe okuphezulu kwekhabhoni futhi zenzelwe izinhlelo zokusebenza ezidinga amandla aphezulu emazingeni okushisa aphezulu.
Lapho ushisela insimbi engagqwali, kubalulekile futhi ukukhetha insimbi yokugcwalisa enamazinga aphansi okulandelela (okwaziwa nangokuthi ukungcola) kwezinto. Lezi yizinto ezisele ezintweni zokusetshenziswa ezisetshenziselwa ukwenza izinsimbi zokugcwalisa, okuhlanganisa i-antimony, i-arsenic, i-phosphorus kanye nesulfure. Zingathinta kakhulu ukumelana nokugqwala kwezinto.
Njengoba insimbi engagqwali ibucayi kakhulu ekufakweni kokushisa, ukulungiswa kwamalunga kanye nokuhlanganiswa okufanele kudlala indima ebalulekile ekulawuleni ukushisa ukuze kulondolozwe izakhiwo zezinto. Ngenxa yezikhala phakathi kwezingxenye noma ukulingana okungalingani, ithoshi kumele lihlale endaweni eyodwa isikhathi eside futhi kudingeka insimbi eyengeziwe yokugcwalisa ukuze kugcwaliswe lezo zikhala. Lokhu kungabangela ukushisa ukuthi kuqongelelane endaweni ethintekile, okungashisa kakhulu ingxenye. Ukulingana okungekuhle kungenza kube nzima kakhulu ukuvala izikhala nokuthola ukungena kwe-weld okudingekayo. Qaphela ukuqinisekisa ukuthi izingxenye zingena ensimbini engagqwali eduze kakhulu nokuphelele ngangokunokwenzeka.
Ukuhlanzeka kwale nto nakho kubaluleke kakhulu. Inani elincane kakhulu lokungcola noma ukungcola emajoyintini ahlanganisiwe kungabangela amaphutha anciphisa amandla kanye nokumelana nokugqwala komkhiqizo wokugcina. Ukuze uhlanze isisekelo ngaphambi kokushisela, sebenzisa ibhulashi elikhethekile lensimbi engagqwali elingasetshenziswanga ensimbini yekhabhoni noma e-aluminium.
Ensimbini engagqwali, ukuzwela kuyimbangela eyinhloko yokulahlekelwa ukumelana nokugqwala. Lokhu kungenzeka uma izinga lokushisa lokushisela kanye nezinga lokupholisa kushintshashintsha kakhulu, kushintsha isakhiwo sezinto ezibonakalayo.
Lokhu kushisela kwe-OD epayipini lensimbi engagqwali, okushiselwe kusetshenziswa i-GMAW kanye ne-regulated metal deposition (RMD) ngaphandle kokushintsha i-root pass, kufana ngokubukeka nangekhwalithi kuma-weld enziwe nge-backflushed GTAW.
Ingxenye ebalulekile yokumelana nokugqwala kwensimbi engagqwali yi-chromium oxide. Kodwa uma okuqukethwe yikhabhoni ku-weld kuphezulu kakhulu, kuzokwakheka i-chromium carbide. Lokhu kubopha i-chromium futhi kuvimbele ukwakheka kwe-chromium oxide oyifunayo, enikeza ukumelana nokugqwala kwensimbi engagqwali. Uma ingekho i-chromium oxide eyanele, izinto ngeke zibe nezakhiwo ezifiselekayo futhi kuzokwenzeka ukugqwala.
Ukuvimbela ukuzwela kuncike ekukhetheni insimbi yokugcwalisa kanye nokulawula ukufakwa kokushisa. Njengoba kushiwo ngaphambili, kubalulekile ukukhetha insimbi yokugcwalisa enesikhabhoni esincane yokushisela insimbi engagqwali. Kodwa-ke, ikhabhoni ngezinye izikhathi iyadingeka ukuze inikeze amandla kwezinye izinhlelo zokusebenza. Ukulawula ukushisa kubaluleke kakhulu lapho izinsimbi zokugcwalisa ezinesikhabhoni esincane zingeyona inketho.
Nciphisa isikhathi lapho indawo yokushisela kanye nendawo ethintekile ekushiseni ihlala khona emazingeni okushisa aphezulu—okuvamile ukubhekwa njengama-degrees Fahrenheit angu-950 kuya ku-1,500 (500 kuya ku-800 Celsius). Uma isikhathi esincane sokushisela sichitha kuleli banga, kulapho kukhiqiza khona ukushisa okuncane. Hlola njalo futhi uqaphele izinga lokushisa le-interpass enkambisweni yokufaka i-soldering.
Enye indlela ukusebenzisa izinsimbi zokugcwalisa eziklanywe ngezingxenye zokuxuba ezifana ne-titanium ne-niobium ukuvimbela ukwakheka kwe-chromium carbide. Ngenxa yokuthi lezi zingxenye nazo zithinta amandla nokuqina, lezi zinsimbi zokugcwalisa azikwazi ukusetshenziswa kuzo zonke izinhlelo zokusebenza.
Ukushisela i-arc ye-gas tungsten (GTAW) ye-root pass kuyindlela yendabuko yokushisela ipayipi lensimbi engagqwali. Lokhu kuvame ukudinga ukushiselwa emuva kwe-argon ukusiza ukuvimbela ukushiswa ngemuva kwe-weld. Kodwa-ke, ukusetshenziswa kwezinqubo zokushisela ngocingo kumapayipi ensimbi engagqwali kuya ngokuya kuvama. Kulezi zinhlelo zokusebenza, kubalulekile ukuqonda ukuthi amagesi ahlukahlukene okuvikela athinta kanjani ukumelana nokugqwala kwezinto.
Lapho kushiselwa insimbi engagqwali kusetshenziswa inqubo yokushiselwa kwensimbi yegesi (i-GMAW), i-argon ne-carbon dioxide, kusetshenziswa ingxube ye-argon ne-oxygen, noma ingxube yegesi emithathu (i-helium, i-argon, ne-carbon dioxide). Ngokuvamile, lezi zingxube ziqukethe kakhulu i-argon noma i-helium kanye ne-carbon dioxide engaphansi kuka-5%, njengoba i-carbon dioxide ifaka ikhabhoni echibini lokushiselwa futhi yandisa ingozi yokuzwela. I-argon emsulwa ayinconywa i-GMAW ensimbini engagqwali.
Intambo yensimbi engagqwali ene-flux yakhelwe ukusebenza ngengxube yendabuko ye-argon engu-75% kanye ne-carbon dioxide engu-25%. I-flux iqukethe izithako ezenzelwe ukuvimbela ikhabhoni ephuma kugesi evikelayo ukuthi ingangcolisi i-weld.
Njengoba izinqubo ze-GMAW sezishintshile, zenze lula ukushintshwa kwamashubhu namapayipi ensimbi engagqwali. Ngenkathi ezinye izinhlelo zokusebenza zingase zidinge izinqubo ze-GTAW, izinqubo zentambo ezithuthukisiwe zinganikeza ikhwalithi efanayo kanye nokukhiqiza okuphezulu ezinhlelweni eziningi zensimbi engagqwali.
Ama-weld e-ID ensimbi engagqwali enziwe nge-GMAW RMD afana ngekhwalithi nokubukeka nama-weld e-OD ahambisanayo.
I-root pass esebenzisa inqubo ye-GMAW ye-short-circuit eguquliwe njenge-Miller's Regulated Metal Deposition (RMD) iqeda i-backflushing kwezinye izinhlelo zokusebenza ze-austenitic stainless steel. I-RMD root pass ingalandelwa yi-pulsed GMAW noma i-flux-cored arc welding fill and cap pads—ushintsho olusindisa isikhathi nemali uma kuqhathaniswa nokusebenzisa i-GTAW nge-back-purging, ikakhulukazi kumapayipi amakhulu.
I-RMD isebenzisa ukudluliselwa kwensimbi okulawulwa ngokunembile ukuze ikhiqize i-arc ezolile, ezinzile kanye ne-weld ichibi. Lokhu kunikeza amathuba amancane okudlula okubandayo noma ukuntuleka kokuhlangana, ukuchitheka okuncane kanye nokudlula kwempande yepayipi esezingeni eliphezulu. Ukudluliselwa kwensimbi okulawulwa ngokunembile kunikeza nokufakwa kwamaconsi okufanayo, okwenza kube lula ukulawula ichibi lokushisela kanye nesivinini sokufaka ukushisa kanye nokushisela.
Izinqubo ezingavamile zingandisa umkhiqizo wokushisela. Uma usebenzisa i-RMD, isivinini sokushisela singaba ngu-6 kuya ku-12 in./min. Ngenxa yokuthi inqubo yandisa umkhiqizo ngaphandle kokushisa okwengeziwe kwezingxenye, iyasiza ekugcineni izakhiwo kanye nokumelana nokugqwala kwensimbi engagqwali. Ukufakwa kokushisa okuncishisiwe kwenqubo kusiza futhi ukulawula ukuguquka kwesisekelo.
Le nqubo ye-GMAW evuvukile inikeza ubude obufushane be-arc, ama-arc cone amancane kanye nokufakwa kokushisa okuncane kunokudluliselwa kwe-pulse evamile yokufutha. Njengoba inqubo ivaliwe, ukukhukhuleka kwe-arc kanye nokwehluka kwebanga eliya endaweni yokusebenza kuqedwa cishe. Lokhu kunikeza ukulawula okulula kwe-chiddle kokushisela endaweni kanye nangaphandle kwendawo. Okokugcina, ukuhlanganisa i-GMAW evuvukile ye-fill and cap bead ne-RMD ye-root bead kuvumela inqubo yokushisela ukuthi yenziwe kusetshenziswa ucingo olulodwa kanye negesi eyodwa, kuqedwe izikhathi zokushintsha kwenqubo.
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