Oku kuvakala kulungile kakhulu ukuba kungaba yinyani, ngoko ke yintoni ingxaki? Ukuwelda kudla ngokufuneka ukuze kwenziwe phantse nantoni na kwenye yeentlobo zentsimbi engagqwaliyo ezingaphezu kwe-150. Ukuwelda intsimbi engagqwaliyo ngumsebenzi onzima. Eminye yale micimbi ibandakanya ubukho be-chromium oxide, indlela yokulawula ubushushu, ukuba yeyiphi inkqubo yokuwelda ekufuneka isetyenziswe, indlela yokuphatha i-chromium ene-hexavalent kunye nendlela yokwenza ngokuchanekileyo.
Nangona kukho ubunzima bokudityaniswa nokugqityezelwa kwesi sixhobo, intsimbi engagqwaliyo isathandwa kwaye ngamanye amaxesha yeyona ndlela ikhethekileyo kumashishini amaninzi. Ukwazi indlela yokuyisebenzisa ngokukhuselekileyo kunye nexesha lokusebenzisa inkqubo nganye yokudityaniswa kubalulekile ekudibaneni ngempumelelo. Oku kunokuba sisitshixo somsebenzi ophumelelayo.
Kutheni ke ukuwelda ngentsimbi engagqwaliyo kunzima kangaka? Impendulo iqala ngendlela eyadalwa ngayo. Intsimbi engagqwaliyo, eyaziwa ngokuba yintsimbi engagqwaliyo, ixutywa ne-10.5% ye-chromium ubuncinane ukuvelisa intsimbi engagqwaliyo. I-chromium eyongeziweyo yenza umaleko we-chromium oxide kumphezulu wentsimbi, nto leyo ethintela uninzi lweentlobo zokugqwala kunye nokugqwala. Abavelisi bongeza ubungakanani obahlukeneyo be-chromium kunye nezinye izinto kwintsimbi ukutshintsha umgangatho wemveliso yokugqibela, baze basebenzise inkqubo enamanani amathathu ukwahlulahlula amanqanaba.
Iintsimbi ezingenasici ezisetyenziswa rhoqo ziquka i-304 kunye ne-316. Eyona ingabizi kakhulu kwezi yi-304, equlethe i-18% ye-chromium kunye ne-8% ye-nickel kwaye isetyenziswa kuyo yonke into ukusuka kwi-trim yemoto ukuya kwizixhobo zasekhitshini. Intsimbi engenasici ye-316 ine-chromium encinci (16%) kunye ne-nickel engaphezulu (10%), kodwa ikwanayo ne-2% ye-molybdenum. Le compound inika i-316 intsimbi engenasici ukumelana ne-chloride kunye ne-chlorine izisombululo, nto leyo eyenza ukuba ibe lolona khetho lufanelekileyo kwiindawo zaselwandle kunye namashishini eekhemikhali kunye namayeza.
Umaleko we-chromium oxide unokuqinisekisa umgangatho wentsimbi engagqwaliyo, kodwa yile nto yenza abawelda baphazamiseke kangaka. Olu thintelo luluncedo lunyusa uxinzelelo lomphezulu wesinyithi, lucothisa ukwakheka kwedama lokuwelda elingulwelo. Impazamo eqhelekileyo kukunyusa ubushushu, njengoko ubushushu obuninzi bunyusa ukugeleza kwedama. Nangona kunjalo, oku kunokuchaphazela kakubi intsimbi engagqwaliyo. Ubushushu obuninzi bunokubangela i-oxidation engaphezulu kunye nokujika okanye ukutsha kwisinyithi esisisiseko. Xa idibene nesinyithi esisetyenziswa kumashishini amakhulu afana nomsi weemoto, oku kuba yinto ephambili.
Ubushushu butshabalalisa ngokupheleleyo ukumelana nokugqwala kwentsimbi engagqwali. Ubushushu obuninzi busetyenziswa xa i-weld okanye indawo echaphazelekayo kubushushu (HAZ) ijika ibe yi-iridescent. Intsimbi engagqwali e-oxidized ivelisa imibala emangalisayo ukusuka kwigolide engwevu ukuya kuluhlaza okwesibhakabhaka nomfusa. Le mibala yenza umfanekiso omhle, kodwa inokubonisa ii-welds ezisenokungahlangabezani neemfuno ezithile ze-welding. Iinkcazo ezingqongqo azithandi umbala we-weld.
Kuyavunywa ngokubanzi ukuba i-gas-shielded tungsten arc welding (GTAW) yeyona ifanelekileyo kwi-stainless steel. Ngokwembali, oku bekuyinyani ngokubanzi. Oku kusenjalo xa sizama ukuzisa loo mibala inesibindi kwi-art weaving ukuze ihlangabezane nemigangatho ephezulu kumashishini afana namandla enyukliya kunye ne-aerospace. Nangona kunjalo, iteknoloji ye-inverter welding yanamhlanje yenze i-gas metal arc welding (GMAW) ibe ngumgangatho wemveliso ye-stainless steel, kungekuphela nje iinkqubo ezizenzekelayo okanye ze-robotic.
Ekubeni i-GMAW iyinkqubo yokufunxa ucingo oluzenzekelayo, inika izinga eliphezulu lokufaka, nto leyo enceda ekunciphiseni ubushushu. Abanye oochwephesha bathi kulula ukuyisebenzisa kune-GTAW kuba ayixhomekekanga kakhulu kwisakhono somshibili kodwa ixhomekeke kakhulu kwisakhono somthombo wamandla okuwelda. Eli linqaku elingaqhelekanga, kodwa uninzi lwezixhobo zamandla ze-GMAW zanamhlanje zisebenzisa imigca ye-synergy ecwangcisiweyo kwangaphambili. Ezi nkqubo zenzelwe ukuseta iiparameter ezifana nombane kunye ne-voltage, kuxhomekeke kwisinyithi esizalisa esifakwe ngumsebenzisi, ubukhulu bezinto, uhlobo lwegesi kunye nobubanzi bentambo.
Ezinye ii-inverters zinokulungisa i-arc kuyo yonke inkqubo yokuwelda ukuze zivelise i-arc echanekileyo rhoqo, ziphathe izithuba phakathi kwamacandelo, kwaye zigcine isantya esiphezulu sokuhamba ukuze zihlangabezane nemigangatho yemveliso kunye nomgangatho. Oku kuyinyani ngakumbi kwi-automated okanye i-robotic welding, kodwa kukwasebenza nakwi-manual welding. Ezinye izixhobo zamandla ezikwimarike zibonelela nge-touch screen interface kunye nolawulo lwetotshi ukuze kube lula ukuseta.
Ukuwelda intsimbi engagqwaliyo ngumsebenzi onzima. Eminye yale miba ibandakanya ukubakho kwe-chromium oxide, indlela yokulawula ubushushu, indlela yokusebenzisa inkqubo yokuwelda, indlela yokuphatha i-chromium ene-hexavalent kunye nendlela yokwenza ngokuchanekileyo.
Ukukhetha igesi efanelekileyo ye-GTAW kudla ngokuxhomekeka kumava okanye ekusebenziseni uvavanyo lokuwelda. I-GTAW, ekwaziwa ngokuba yi-tungsten inert gas (TIG), kwiimeko ezininzi isebenzisa kuphela igesi engangeniyo, ngokuqhelekileyo i-argon, i-helium, okanye umxube wazo zombini. Ukufakwa okungafanelekanga kwegesi yokukhusela okanye ubushushu kunokubangela ukuba nayiphi na i-weld ibe yi-domed kakhulu okanye ifane nentambo, kwaye oku kuya kuyithintela ekudibaneni nesinyithi esijikelezileyo, okubangela i-weld engathandekiyo okanye engafanelekanga. Ukuchonga ukuba loluphi umxube olungele i-weld nganye kunokuthetha uvavanyo oluninzi kunye neempazamo. Imigca yemveliso ye-GMAW ekwabelwana ngayo inceda ukunciphisa ixesha elichithwayo kwizicelo ezintsha, kodwa xa kufuneka umgangatho ongqongqo, indlela yokuwelda ye-GTAW ihlala iyeyona ndlela ikhethwayo.
Ukuwelda intsimbi engagqwaliyo kuyingozi empilweni yabo banetotshi. Eyona ngozi inkulu ibangelwa ngumsi okhutshwa ngexesha lenkqubo yokuwelda. I-chromium eshushu ivelisa i-compound ebizwa ngokuba yi-hexavalent chromium, eyaziwa ngokuba yonakalisa inkqubo yokuphefumla, izintso, isibindi, ulusu namehlo kwaye ibangela umhlaza. Abawelda kufuneka basoloko benxibe izixhobo zokuzikhusela, kuquka ne-respirator, kwaye baqinisekise ukuba igumbi linomoya ococekileyo ngaphambi kokuba baqalise ukuwelda.
Iingxaki ngentsimbi engagqwaliyo azipheli emva kokuba ukuwelda kugqityiwe. Intsimbi engagqwaliyo ikwafuna ingqalelo ekhethekileyo kwinkqubo yokugqiba. Ukusebenzisa ibrashi yentsimbi okanye i-polishing pad engcoliswe yintsimbi yekhabhoni kunokonakalisa umaleko okhuselayo we-chromium oxide. Nokuba umonakalo awubonakali, ezi zinto zingcolisayo zinokwenza imveliso egqityiweyo ibe sesichengeni sokugqwala okanye ukugqwala.
UTerrence Norris yiNjineli yeZicelo ePhakamileyo eFronius USA LLC, 6797 Fronius Drive, Portage, IN 46368, 219-734-5500, www.fronius.us.
URhonda Zatezalo ngumbhali ozimeleyo weCrearies Marketing Design LLC, 248-783-6085, www.crearies.com.
Itekhnoloji yanamhlanje yokuwelda ye-inverter yenze i-GMAW yegesi ibe ngumgangatho wokwenziwa kwentsimbi engagqwaliyo, kungekuphela nje kwiinkqubo ezizenzekelayo okanye zerobhothi.
I-WELDER, eyayisakuba yi-Practical Welding Today, imele abantu bokwenene abenza iimveliso esizisebenzisayo nesisebenza ngazo yonke imihla. Le magazini ibikhonza uluntu oludibanisa iintsimbi eMntla Melika kangangeminyaka engaphezu kwama-20.
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