Lokhu kuzwakala kukuhle kakhulu ukuba yiqiniso, pho inkinga ikuphi? Ukushisela kuvame ukudingeka ukuze kwenziwe noma yini kusuka kwenye yezinhlobo zensimbi engagqwali ezingaphezu kuka-150. Ukushisela insimbi engagqwali kuwumsebenzi oyinkimbinkimbi. Ezinye zalezi zinkinga zifaka phakathi ukuba khona kwe-chromium oxide, indlela yokulawula ukufakwa kokushisa, ukuthi iyiphi inqubo yokushisela okufanele isetshenziswe, indlela yokusingatha i-chromium ene-hexavalent nokuthi ungayenza kanjani kahle.
Naphezu kobunzima bokushisela nokuqeda le nto, insimbi engagqwali isalokhu ithandwa futhi ngezinye izikhathi iyindlela ewukuphela kwayo ezimbonini eziningi. Ukwazi ukuthi ungayisebenzisa kanjani ngokuphephile nokuthi ungayisebenzisa nini inqubo ngayinye yokushisela kubalulekile ekushiseleni okuphumelelayo. Lokhu kungaba yisihluthulelo somsebenzi ophumelelayo.
Ngakho-ke kungani ukushisela insimbi engagqwali kuwumsebenzi onzima kangaka? Impendulo iqala ngendlela eyadalwa ngayo. Insimbi ethambile, eyaziwa nangokuthi insimbi engagqwali, ixutshwa okungenani ne-10.5% chromium ukuze ikhiqize insimbi engagqwali. I-chromium eyengeziwe yakha ungqimba lwe-chromium oxide ebusweni bensimbi, okuvimbela izinhlobo eziningi zokugqwala nokugqwala. Abakhiqizi banezela amanani ahlukahlukene e-chromium nezinye izinto ensimbini ukuze bashintshe ikhwalithi yomkhiqizo wokugcina, bese besebenzisa uhlelo olunezinombolo ezintathu ukuze bahlukanise amamaki.
Izinsimbi ezingagqwali ezisetshenziswa kakhulu zifaka phakathi u-304 no-316. Ezishibhile kakhulu kulezi yi-304, equkethe u-18% we-chromium kanye no-8% we-nickel futhi isetshenziswa kukho konke kusukela ekuhlobiseni izimoto kuya kumishini yasekhishini. Insimbi engagqwali engu-316 iqukethe i-chromium encane (16%) kanye ne-nickel eyengeziwe (10%), kodwa futhi iqukethe u-2% we-molybdenum. Le nhlanganisela inikeza u-316 wensimbi engagqwali ukumelana okwengeziwe nama-chloride kanye nezixazululo ze-chlorine, okwenza kube ukukhetha okungcono kakhulu ezindaweni zasolwandle kanye nezimboni zamakhemikhali nezemithi.
Ingqimba ye-chromium oxide ingaqinisekisa ikhwalithi yensimbi engagqwali, kodwa yilokhu okwenza abashiseli baphazamiseke kangaka. Lesi sivimbelo esiwusizo sandisa ukucindezelwa kobuso bensimbi, sinciphise ukwakheka kwechibi lokushisela eliwuketshezi. Iphutha elivamile ukwandisa ukufakwa kokushisa, njengoba ukushisa okwengeziwe kwandisa ukugeleza kwechibi. Kodwa-ke, lokhu kungathinta kabi insimbi engagqwali. Ukushisa okuningi kungabangela ukushiswa okwengeziwe kanye nokugoba noma ukusha ngensimbi eyisisekelo. Uma kuhlanganiswa nensimbi eshidi esetshenziswa ezimbonini ezinkulu ezifana nokukhipha umoya ezimotweni, lokhu kuba yinto eza kuqala.
Ukushisa kubhubhisa ngokuphelele ukumelana nokugqwala kwensimbi engagqwali. Ukushisa okuningi kusetshenziswa lapho i-weld noma indawo ethintekile ekushiseni ezungezile (i-HAZ) iphenduka ibe nsundu. Insimbi engagqwali e-oxidized ikhiqiza imibala emangalisayo kusukela kwegolide elikhanyayo kuya koluhlaza okwesibhakabhaka okumnyama nokunsomi. Le mibala yenza umfanekiso omuhle, kodwa ingabonisa ama-weld angase angahlangabezani nezidingo ezithile zokushisela. Imininingwane eqinile kakhulu ayithandi umbala we-weld.
Ngokuvamile kuyamukelwa ukuthi ukushisela i-arc ye-tungsten evikelwe ngegesi (i-GTAW) kufaneleka kakhulu ensimbini engagqwali. Ngokomlando, lokhu bekuyiqiniso ngomqondo ojwayelekile. Lokhu kuseyiqiniso uma sizama ukuletha leyo mibala enesibindi ekuthungeni kobuciko ukuze kuhlangatshezwane nezindinganiso zekhwalithi ephezulu ezimbonini ezifana namandla enuzi kanye nezindiza. Kodwa-ke, ubuchwepheshe besimanje bokushisela i-inverter buye benza ukushisela i-arc yensimbi yegesi (i-GMAW) kube yindinganiso yokukhiqizwa kwensimbi engagqwali, hhayi nje izinhlelo ezizenzakalelayo noma zamarobhothi.
Njengoba i-GMAW iyinqubo yokuphakelwa kwentambo okuzenzakalelayo, inikeza izinga eliphezulu lokufakwa, okusiza ukunciphisa ukufakwa kokushisa. Abanye ochwepheshe bathi kulula ukuyisebenzisa kune-GTAW ngoba incike kancane ekhonweni lomshiseli kodwa incike kakhulu ekhonweni lomthombo wamandla okushisela. Leli iphuzu elingaqondakali, kodwa iningi lamandla kagesi e-GMAW anamuhla asebenzisa imigqa yokuvumelanisa ehlelwe kusengaphambili. Lezi zinhlelo zenzelwe ukusetha amapharamitha afana nogesi kanye ne-voltage, kuye ngokuthi insimbi yokugcwalisa ifakwe umsebenzisi, ubukhulu bezinto, uhlobo lwegesi kanye nobubanzi bentambo.
Amanye ama-inverter angalungisa i-arc kuyo yonke inqubo yokushisela ukuze akhiqize i-arc enembile njalo, aphathe izikhala phakathi kwezingxenye, futhi agcine isivinini esikhulu sokuhamba ukuze ahlangabezane namazinga okukhiqiza kanye nekhwalithi. Lokhu kuyiqiniso ikakhulukazi ngokushisela okuzenzakalelayo noma kwerobhothi, kodwa futhi kusebenza nasekushiseleni ngesandla. Amanye amandla emakethe anikeza isikhombikubona sesikrini sokuthinta kanye nezilawuli zethoshi ukuze kube lula ukusetha.
Ukushisela insimbi engagqwali kuwumsebenzi oyinkimbinkimbi. Ezinye zalezi zinkinga zifaka phakathi ukuba khona kwe-chromium oxide, indlela yokulawula ukufakwa kokushisa, ukuthi iyiphi inqubo yokushisela okufanele isetshenziswe, indlela yokusingatha i-chromium ene-hexavalent kanye nendlela yokuyenza kahle.
Ukukhetha igesi efanele ye-GTAW kuvame ukuncika kokuhlangenwe nakho noma ukusetshenziswa kokuhlolwa kokushisela. I-GTAW, eyaziwa nangokuthi i-tungsten inert gas (TIG), ezimweni eziningi isebenzisa kuphela igesi engasebenzisi igesi, ngokuvamile i-argon, i-helium, noma ingxube yakho kokubili. Ukujova okungalungile kwegesi yokuvikela noma ukushisa kungabangela noma yikuphi ukushisela ukuba kufakwe ngokweqile noma kufane nentambo, futhi lokhu kuzokuvimbela ekuxubeni nensimbi ezungezile, okuholela ekushiseleni okungathandeki noma okungafanele. Ukunquma ukuthi iyiphi ingxube engcono kakhulu kushisele ngayinye kungasho ukuzama okuningi namaphutha. Imigqa yokukhiqiza ye-GMAW eyabiwe isiza ukunciphisa isikhathi esichithwayo ezinhlelweni ezintsha, kodwa lapho kudingeka ikhwalithi eqinile kakhulu, indlela yokushisela ye-GTAW ihlala iyindlela ekhethwayo.
Ukushisela insimbi engagqwali kubeka impilo engozini kulabo abanethoshi. Ingozi enkulu ibangelwa umusi okhishwa ngesikhathi senqubo yokushisela. I-chromium efudumele ikhiqiza i-compound ebizwa ngokuthi i-hexavalent chromium, eyaziwa ngokulimaza uhlelo lokuphefumula, izinso, isibindi, isikhumba namehlo futhi ibangele umdlavuza. Abashisela kumele bahlale begqoke imishini yokuzivikela, okuhlanganisa nomshini wokuphefumula, futhi baqinisekise ukuthi igumbi linomoya omuhle ngaphambi kokuqala ukushisela.
Izinkinga ngensimbi engagqwali azipheli ngemva kokushisela sekuqediwe. Insimbi engagqwali idinga ukunakwa okukhethekile enqubweni yokuqeda. Ukusebenzisa ibhulashi lensimbi noma iphedi yokupholisha engcoliswe yinsimbi yekhabhoni kungalimaza ungqimba lwe-chromium oxide oluvikelayo. Ngisho noma umonakalo ungabonakali, lezi zinto ezingcolisayo zingenza umkhiqizo oqediwe ube sengozini yokugqwala noma okunye ukugqwala.
UTerrence Norris unguNjiniyela Omkhulu Wezicelo kwa-Fronius USA LLC, 6797 Fronius Drive, Portage, IN 46368, 219-734-5500, www.fronius.us.
URhonda Zatezalo ungumbhali ozimele weCrearies Marketing Design LLC, 248-783-6085, www.crearies.com.
Ubuchwepheshe besimanje bokushisela i-inverter buye benza i-gas GMAW yaba yindinganiso yokukhiqizwa kwensimbi engagqwali, hhayi nje izinhlelo ezizenzakalelayo noma zamarobhothi.
I-WELDER, eyayibizwa ngokuthi i-Practical Welding Today, imelela abantu bangempela abenza imikhiqizo esiyisebenzisayo futhi esisebenza nayo nsuku zonke. Lo magazini ubulokhu ukhonza umphakathi wokushisela eNyakatho Melika iminyaka engaphezu kwengu-20.
Manje ngokufinyelela okugcwele kuhlelo lwedijithali lwe-FABRICATOR, ukufinyelela okulula ezinsizeni ezibalulekile zemboni.
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