Iziseko zobuGcisa bokuwelda
Ukuwelding kukudibanisa iintsimbi ezinesakhiwo esifanayo okanye esifana noko phantsi kwempembelelo yobushushu, enokuthi okanye ingabi nakongezwa intsimbi efanayo okanye efana noko. Ngoncedo lwewelding iindawo zidibana ngokungenakwahlulwa zibe yinto enye epheleleyo. Iwelding elungileyo ifuna ukudityaniswa okusondeleyo, okufezekiswa kuphela xa kwindawo yewelding kunyibilika nezinto ezisisiseko (indawo yomthungo).
Ukuwelda ngombane we-arc
Kwizakhiwo zentsimbi kuqala kuqwalaselwa i-arc welding, apho ubushushu obufunekayo bufunyanwa ngedangatye lombane. I-arc yomlilo yenziwa phakathi kwento esisiseko kunye noko kubizwa ngokuba yi-electrode, ethi ngelo xesha inyibilike ize inikeze izinto ezongezelelekileyo. Ukukhethwa ngokuchanekileyo kwezinto ezongezelelekileyo (i-electrode) kunempembelelo enkulu kwiimpawu zekhonkco elidityanisiweyo. Ii-electrode zikhethwa ngokwemilinganiselo yeempawu zezinto ezisisiseko ezidityanisiweyo. Ukukhetha ii-electrode, ukumisela iimeko zokuwelda kufuna ulwazi lobungcali, yaye ngenxa yoko kudaliwe iziko leenjineli abafundiswe ngokukodwa ‘njengeengcali kubuchwephesha bokuwelda’, umsebenzi wazo, phakathi kwezinye izinto, kukongamela imisebenzi yokuwelda nokuphinda rhoqo izatifikethi zabaweldi.
Ukuweldisa kunye nokusika ngegesi
Xa kusenziwa ukuwelda ngegesi, ubushushu obufunekayo buveliswa ngokutsha kwerhasi, ukuze izinto ezisisiseko nezongezelelekileyo zinyibilike. Okubaluleke ngakumbi kukuba ukusika. Isibane sokusika sinomjelo wobushushu, osebenza njengakuwelda, kunye nomjelo owongezelelweyo wokusika weoksijini. Intsimbi efudunyezwe lidangatye elishushu iyagqobozeka ize ivuthululwe sisihluzi seoksijini. Ukusika kunika imiphezulu egudileyo nenochaneko eyaneleyo kwiinjongo ezininzi zezakhiwo zentsimbi ngaphandle kokulungiswa okungaphezulu.
Ukuweldwa okunokwenzeka
Kuvavanyo lweendawo ezidityanisiweyo ngentsimbi kufuneka kuthathelwe ingqalelo ukuba ngexesha lenkqubo yokuwelda ukubunjwa kwesongezelelo, kwanokwemathiriyeli esisiseko, kunokutshintsha kakhulu. Ukutshintsha kwesakhiwo nako kunentsingiselo enkulu – phakathi komthungo onyibilikileyo nemathiriyeli esisiseko engatshintshanga kukho, ngokuxhomekeke kwinqanaba lesenzo sobushushu, ummandla onezityalo ezahlukeneyo yaye ngenxa yoko oneempawu ezahlukeneyo. Kufuphi nomthungo kukho indawo apho imathiriyeli esisiseko inyibilikileyo (indawo ye-uvar) yaye apho kwenzeka ukudityaniswa phakathi kwendawo yokuwelda nemathiriyeli esisiseko. Indawo ejikelezileyo yemathiriyeli nayo ifudunyezwa kakhulu, nangona apho indawo yokunyibilika ingasafikelelwanga. Kule ndawo yokushushumbisa kwakhona kuvela iinguqu ezinkulu kwisakhiwo, nto leyo eyenza ukuba kaninzi ibe yeyona nto igqibayo kwiimpawu zekhonkco lonke elidityanisiweyo.
Ukuqhekeka kwentsingo kuthetha ukubonakala kweentanda kwintingo, ezivela ngoko nangoko emva kokuwelda kusekho ubushushu obuphezulu okanye mhlawumbi kuphela xa kuphola kummandla wokukhanya okuluhlaza (malunga ne 300oC). Ukuqhekeka ubukhulu becala luphawu lwee-electrode; phantse kuvela kuphela kwii-electrode ezigqunyiweyo, eziyimfuneko kanye kwizakhiwo zentsimbi. Ukuze kuvele iintanda kufuneka kuhlangatyezwane neemeko ezimbini, ezizezi uxinzelelo oluphezulu ngenxa yenkqubo yokuwelda okanye ezinye iimpembelelo zangaphandle, kwakunye nokwanda kokuqina kwezinto.
Ngaphandle kotshintsho lwemetallurgical ekubunjweni nasekwakhiweni kwezinto, zibalulekile neenkqubo zomzimba, ezinxulumene nobuninzi obukhulu bobushushu obungeniswa kwizinto ngexesha le-welding, kunye namaqondo obushushu aphezulu afikelelwayo ngaloo ndlela. Ukufudumeza akwenzeki ngokulinganayo, koko kuphela kwiindawo ezincinane ezilinganiselweyo. Ukwanda kobushushu okunxulumene nokufudumeza kuthintelwa luxinzelelo lwangaphakathi lwendawo eshushu ngezinto ezingashushu. Ukongezelela koko kuvela noxinzelelo lwangaphandle, kuba iinxalenye kufuneka ziqiniswe ngokuqinileyo ngexesha le-welding, ngoko ngexesha lokufudumeza kuvela ukucuthwa kweplastiki. Ngexesha lokupholisa, umthungo nendawo ewungqongileyo ziyancipha kakhulu (ukuncipha). Xa kupholiswa, ngenxa yokuthintelwa kokwandiswa kufuneka kuvele iimpembelelo ezinyanzelekileyo (iimpembelelo zokuncipha). Ngaphambi kokufudumeza iindawo eziza kuwelditshwa ukuya kwi-200 oC ukuya kwi-300 oC, ukupholisa kungacothiswa kakhulu. Ngenxa yokuncipha kwempembelelo yokunyibilikisa, kufumaneka ukwakheka kwesakhiwo okungcono, ukuqina kuhlala kuncinci.
Uvavanyo lwezinto kunye nemisebenzi yokuqinisa ngocingo
Ngokubanzi: Kuba umgangatho wemisebenzi ye-welding uxhomekeke kuthotho lweemeko, kwaye ekugqibeleni nakubuchule kunye nokuthembeka komsebenzi onolwazi, kuyimfuneko ukubeka iliso elichanekileyo nokuvavanya yonke imisebenzi ye-welding. Phakathi kovavanyo kukhankanywa ezo zokumisela ukukwazi ukuweldisa kwezinto kunye nee-electrode, ukuthelekisa iimeko zokuweldisa neenkqubo zokuwelda kwimeko ethile, iimvavanyo zeesampuli njl.
Umz. 1 - Uvavanyo lokugoba kweweldi yokudityaniswa
Uvavanyo lokugoba komthungo odityanisiweyo: Olu luvavanyo lokugoba ibhimu elula enecandelo elixande (umz. 1), apho umsele wobude ophathwe ngesangqa kwifayibha etsaliweyo uphinda udityaniswe ngomqolo omnye, yaye oko kubushushu begumbi. Umthungo ubangela ukwehla okukhulu kokukwazi ukuguquka, ngoko ke iimvavanyo zihlala ziqhekeka ngokupheleleyo ngendlela ebhityileyo kunye ngesiquphe. I-engile yokugoba inkulu kwiipleyiti ezibhityileyo, yaye iyancipha njengoko ubukhulu bepleyiti busanda.
Ukuqina xa kukho inotshi: Kuvavanyo lokugoba intingo, iintanda zihlala ziqala ukubonakala kuqala kwintingo ngokwayo, nto leyo ekhokelela ekophukeni okubuthathaka. Izinto ezisisiseko kufuneka zikwazi ukwamkela umthwalo ovela ngequbuliso xa intingo iqhuma kabukhali. Kufuneka kufuneke ukuba intanda kummandla wendawo eweldiweyo ingangeni ngokukhawuleza nakwizinto ezisisiseko, koko intanda mayiqhubele phambili kancinci kuphela. Izinto ezisisiseko kufuneka zibe nokuqina okwaneleyo ukuze zamkele lo mthwalo wexesha elifutshane, kwaye eli khono kufuneka lihlale likho ngokwaneleyo nakumaqondo obushushu asezantsi. Ukuqina xa kukho inotshi kunye nezinye iipropati zoomatshini zixhomekeke kakhulu kubushushu apho uvavanyo luqhutywa khona. Kumaqondo obushushu asezantsi, umzekelo ngaphantsi kwe 0 oC kunokwehla kuye kufikelela kwiqhezu lexabiso eliku 20 oC. Indawo yokuhla ngokukhawuleza ibalulekile ekuvavanyeni into ethile. Kwizakhiwo zentsimbi ezidityanisiweyo namhlanje kufunwa izinto ezinokumelana kakuhle nokuguga, oko kukuthi amandla aphezulu okunqanda impembelelo xa kubanda kwiisampuli ezolulweyo.
Sl. 2 - Ukuguquka kwiimeko zoxinzelelo lwemijelo yesikroba
Ubunzima: Kubalulekile kakhulu ukubonakala kobunzima kwindawo yokudibanisa ngokuwelda. Kubalulekile ukwazi ukwanda kobunzima, kuba ukolula ekwaphukeni kwehla ngokukhawuleza xa ubunzima bonyuka (sl. 3), ngoxa amandla okutsalwa σB enyuka phantse ngokwemilinganiselo nobunzima beBrinell HB. Kwiintsimbi zokwakha malunga σB = 0,36*HB. Omnye umzekelo wobunzima bomthungo omkhulu we-engile kwi-I-beam uboniswe ku sl. 4. Kwindawo yotshintsho kukho umahluko omkhulu kubunzima kumgama omncinci kakhulu. Umkhondo wobunzima uxhomekeke kwisakhiwo esenziweyo. Umgca σ-ε-l utshintsha ngendlela efanayo nobunzima njengakwindlela yoxinzelelo lwenotshi (sl. 2).
Sl. 3 - Ubunzima beBrinell kunye nokolula
Sl. 4 - Ukuqina kwindawo yeweld entanyeni yebhimu ye-I edityanisiweyo
Uvavanyo olungonakalisi lwezihlanganisi ezidityanisiweyo ezigqityiweyo
Ukungena ngemiqadi – Xa kungena imiqa kwizikhuseli ezincinane, umfanekiso we-X-ray unokwenziwa ubonakale kwisikrini esinye. Endaweni yemitha ye-X kusenokusetyenziswa imitha ye-gamma evela kwizinto eziradioactive. Umfanekiso we-X-ray uvumela ukuba kugwetywe umgangatho womthungo. I-slag ebandakanyiweyo okanye iipori, kwakunye neempazamo ekudityaniseni kunye neentanda, kunokuthi ngolu hlobo kufunyaniswe kwaye, xa kuyimfuneko, kususwe.
Ukuhamba kwemagnethi – Kwenziwa intsimi yemagnethi kule ndawo yentsimbi evavanywayo, ze iifayili ezigalelweyo zicwangciswe ngokwentsimi. Iimpazamo ezinokuvela kwintsimi yemagnethi zinokubonisa iintanda. Le ndlela isebenza kakuhle ngakumbi ekufumaneni iintanda ezingaphezulu, kodwa ayinabuntununtunu obuphezulu ngokuthelekisa nezinxweme ze-slags kunye nemingxuma, kwakunye neentanda ezikwindawo engaphakathi yamacwecwe ashinyeneyo.
Uvavanyo nge-ultrasound – Amaza esandi amafutshane kakhulu abonakaliswa kungekuphela kwimiphezulu yemida, kodwa nakwimiphezulu yokwahlula ngaphakathi njengoko kumfoka okanye kwimihlathi yokwahlukana.