U: Muva nje sesiqalile ukwenza umsebenzi odinga ukuthi izingxenye ezithile zenziwe ngokuyinhloko ngensimbi engagqwali engu-304, ehlanganiswe yodwa kanye nensimbi ethambile. Sibhekane nezinkinga ezithile ngokuqhekeka kwensimbi phakathi kwensimbi engagqwali kanye nensimbi engagqwali efika ku-1.25″ ubukhulu. Kukhulunywe ukuthi sinamazinga aphansi e-ferrite. Ungachaza ukuthi iyini nokuthi ungayilungisa kanjani?
A: Umbuzo omuhle lowo. Yebo, singakusiza uqonde ukuthi kusho ukuthini ukuthi i-ferrite ephansi nokuthi ungayivimbela kanjani.
Okokuqala, ake sibheke incazelo yensimbi engagqwali (SS) nokuthi i-ferrite ihlobene kanjani namajoyinti ahlanganisiwe. Insimbi emnyama nama-alloy aqukethe insimbi engaphezu kuka-50%. Lokhu kufaka phakathi zonke izinsimbi ze-carbon ne-stainless, kanye namanye amaqembu athile. I-aluminium, ithusi, ne-titanium azinazo insimbi, ngakho-ke ziyizibonelo ezinhle kakhulu zama-alloy angewona awensimbi.
Izingxenye eziyinhloko zale alloy yi-carbon steel enokuqukethwe kwensimbi okungenani okungu-90% kanye ne-stainless steel enokuqukethwe kwensimbi okungu-70 kuya ku-80%. Ukuze ihlukaniswe njenge-SS, kumele okungenani ibe ne-chromium engu-11.5% eyengeziwe. Amazinga e-Chromium angaphezu kwalesi silinganiso esincane akhuthaza ukwakheka kwefilimu ye-chromium oxide ezindaweni zensimbi futhi avimbele ukwakheka kwe-oxidation efana nokugqwala (i-iron oxide) noma ukugqwala kokuhlasela kwamakhemikhali.
Insimbi engagqwali ihlukaniswe kakhulu ngamaqembu amathathu: i-austenitic, i-ferritic kanye ne-martensitic. Igama lawo livela esakhiweni sekristalu lapho izinga lokushisa legumbi lakhiwe khona. Elinye iqembu elivamile insimbi engagqwali ephindwe kabili, okuyibhalansi phakathi kwe-ferrite ne-austenite esakhiweni sekristalu.
Amagreyidi ase-Austenitic, uchungechunge lwama-300, aqukethe i-chromium engu-16% kuya ku-30% kanye ne-nickel engu-8% kuya ku-40%, akha isakhiwo sekristalu se-austenitic ikakhulukazi. Izithambisi ezifana ne-nickel, ikhabhoni, i-manganese, ne-nitrogen zengezwa ngesikhathi senqubo yokwenza insimbi ukusiza ekwakheni isilinganiso se-austenite-ferrite. Amanye amagreyidi avamile angama-304, 316 kanye no-347. Inikeza ukumelana okuhle kokugqwala; isetshenziswa kakhulu ezimbonini zokudla, zamakhemikhali, zemithi kanye nezimboni ze-cryogenic. Ukulawula ukwakheka kwe-ferrite kunikeza ukuqina okuhle kakhulu emazingeni okushisa aphansi.
I-Ferritic SS iyibanga lochungechunge lwama-400 elinobuthi obuphelele, liqukethe i-chromium engu-11.5% kuya ku-30%, futhi linesakhiwo sekristalu se-ferritic ikakhulukazi. Ukuze kukhuthazwe ukwakheka kwe-ferrite, iziqinisi zifaka i-chromium, i-silicon, i-molybdenum kanye ne-niobium ngesikhathi sokukhiqizwa kwensimbi. Lezi zinhlobo ze-SS zivame ukusetshenziswa ezinhlelweni zokukhipha umoya ezimotweni kanye nasezinjinini zamandla futhi zinezicelo ezilinganiselwe zokushisa okuphezulu. Izinhlobo eziningana ezivame ukusetshenziswa: 405, 409, 430 kanye no-446.
Amagreyidi e-Martensitic, abizwa nangokuthi uchungechunge lwama-400, njenge-403, 410, kanye ne-440, anamandla kazibuthe, aqukethe i-chromium engu-11.5% kuya ku-18%, futhi anesakhiwo sekristalu se-martensitic. Le nhlanganisela inokuqukethwe kwegolide okuphansi kakhulu, okwenza kube okungabizi kakhulu ukukhiqiza. Anikeza ukumelana nokugqwala, amandla aphezulu, futhi avame ukusetshenziswa ezitsheni zokudla, emishinini yamazinyo neyokuhlinza, ezitsheni zokupheka, nakwezinye izinhlobo zamathuluzi.
Uma ushisela insimbi engagqwali, uhlobo lwe-substrate kanye nokusetshenziswa kwayo okusebenzayo kuzonquma insimbi yokugcwalisa efanele okufanele isetshenziswe. Uma usebenzisa inqubo yegesi yokuvikela, kungadingeka ukuthi unake kakhulu izingxube zegesi yokuvikela ukuze uvimbele izinkinga ezithile ezihlobene nokushisela.
Ukuze uhlanganise i-304 kuyo, uzodinga i-electrode ye-E308/308L. I-“L” imele ikhabhoni ephansi, okusiza ekuvimbeleni ukugqwala kwe-intergranular. Okuqukethwe kwekhabhoni kwalawa ma-electrode kungaphansi kuka-0.03%, uma leli nani lidlula, ingozi yokufakwa kwekhabhoni emingceleni yokusanhlamvu kanye nokubopha kwe-chromium ukwakha ama-carbide e-chromium iyanda, okunciphisa ngempumelelo ukumelana nokugqwala kwensimbi. Lokhu kuba sobala uma ukugqwala kwenzeka endaweni ethintekile ekushiseni (HAZ) yama-weld ensimbi engagqwali. Okunye okucatshangelwayo ngensimbi engagqwali yebanga L ukuthi inamandla aphansi okubamba emazingeni okushisa aphezulu okusebenza kunamazinga ensimbi engagqwali aqondile.
Njengoba i-304 iwuhlobo lwensimbi engagqwali oluyi-austenitic, insimbi ehambisanayo izoqukatha iningi le-austenite. Kodwa-ke, i-electrode ngokwayo izoqukatha i-ferrite stabilizer, njenge-molybdenum, ukukhuthaza ukwakheka kwe-ferrite ensimbini ehlanganisiwe. Abakhiqizi bavame ukubhala ububanzi obujwayelekile benani le-ferrite lensimbi ehlanganisiwe. Njengoba kushiwo ngaphambili, i-carbon iyi-austenitic stabilizer enamandla futhi ngenxa yalezi zizathu kubalulekile ukuvimbela ukungezwa kwayo ensimbini ehlanganisiwe.
Izinombolo ze-Ferrite zithathwe eshadini le-Scheffler kanye neshadi le-WRC-1992, ezisebenzisa amafomula alinganayo e-nickel ne-chromium ukubala inani elibekwa eshadini elinikeza inombolo evamile. Inombolo ye-ferrite ephakathi kuka-0 no-7 ihambelana nephesenti levolumu yesakhiwo se-ferritic crystal esikhona ensimbini ye-weld, nokho, ngamaphesenti aphezulu, inombolo ye-ferrite iyanda ngokushesha. Khumbula ukuthi i-ferrite ku-SS ayifani ne-ferrite yensimbi yekhabhoni, kodwa iyisigaba esibizwa ngokuthi i-delta ferrite. Insimbi engagqwali yase-Austenitic ayidluli ezinguqukweni zesigaba ezihlotshaniswa nezinqubo zokushisa okuphezulu njengokwelashwa kokushisa.
Ukwakheka kwe-ferrite kuyafiseleka ngoba ithambile kakhulu kune-austenite, kodwa kumele ilawulwe. Okuqukethwe kwe-ferrite okuphansi kunganikeza ama-welds ukumelana okuhle kakhulu nokugqwala kwezinye izinhlelo zokusebenza, kodwa avame kakhulu ukuqhekeka okushisa ngesikhathi sokushisela. Ukusetshenziswa okuvamile, inani lama-ferrite kufanele libe phakathi kuka-5 no-10, kodwa ezinye izinhlelo zokusebenza zingadinga amanani aphansi noma aphezulu. Ama-ferrite angahlolwa kalula endaweni yokusebenza ngesibonakaliso se-ferrite.
Njengoba ushilo ukuthi unezinkinga zokuqhekeka kanye nama-ferrite aphansi, kufanele ubhekisise insimbi yakho yokugcwalisa bese uqinisekisa ukuthi ikhiqiza ama-ferrite anele – cishe angu-8 kufanele enze ubuqili. Futhi, uma usebenzisa i-flux-cored arc welding (FCAW), lezi zinsimbi zokugcwalisa zivame ukusebenzisa igesi yokuvikela engu-100% carbon dioxide noma ingxube ye-75% argon kanye ne-25% CO2, okungabangela ukuthi insimbi yokugcwalisa imunce ikhabhoni. Ungashintshela enqubweni yokugcwalisa i-arc yensimbi (GMAW) bese usebenzisa ingxube ye-argon engu-98%/2% oxygen ukuze unciphise amathuba okufakwa kwekhabhoni.
Uma kushintshwa insimbi engagqwali ibe yinsimbi yekhabhoni, kufanele kusetshenziswe izinto zokugcwalisa i-E309L. Le nsimbi yokugcwalisa isetshenziswa ngokukhethekile ekushisweni kwensimbi okuhlukile, okwakha inani elithile le-ferrite ngemva kokuba insimbi yekhabhoni incibilikisiwe kushintshwa. Ngenxa yokuthi insimbi yekhabhoni imunca ikhabhoni ethile, iziqinisi ze-ferrite zengezwa kushintshwa ukuze kulwiswane nokuthambekela kwekhabhoni ekwakheni i-austenite. Lokhu kuzosiza ekuvimbeleni ukuqhekeka kokushisa ngesikhathi sokushiswa.
Ekuphetheni, uma ufuna ukulungisa imifantu eshisayo kuma-weld ensimbi engagqwali e-austenitic, hlola ukuthi insimbi ye-ferrite filler eyanele yini bese ulandela umkhuba omuhle wokushisela. Gcina ukushisa okungaphakathi kungaphansi kwama-50 kJ/in, gcina amazinga okushisa aphakathi kuya kwaphansi, futhi uqinisekise ukuthi amajoyinti e-solder ahlanzekile ngaphambi kokushisela. Sebenzisa igeyiji efanele ukuhlola inani le-ferrite ku-weld, uhlose ama-5-10.
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.
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