Wannan labarin daga Wenzhou Tianyu Electronic Co., Ltd. ya bayyana abin da za a yi la'akari da shi yayin ƙayyade ƙarfe masu cikawa don walda bakin ƙarfe.
Ƙarfin da ke sa bakin ƙarfe ya zama mai kyau - ikon daidaita halayen injina da juriya ga tsatsa da iskar shaka - suma suna ƙara sarkakiyar zaɓar ƙarfe mai cikawa da ya dace don walda. Ga kowane haɗin kayan tushe, kowane nau'in lantarki da yawa na iya dacewa, ya danganta da matsalolin farashi, yanayin sabis, halayen injin da ake so da kuma batutuwa da yawa da suka shafi walda.
Wannan labarin ya bayar da tushen fasaha da ake buƙata don bai wa mai karatu fahimtar sarkakiyar batun sannan ya amsa wasu daga cikin tambayoyin da aka fi yi wa masu samar da ƙarfen cika. Ya kafa jagororin gabaɗaya don zaɓar ƙarfen cika bakin ƙarfe da ya dace - sannan ya bayyana duk keɓantattun jagororin! Labarin bai ƙunshi hanyoyin walda ba, domin wannan batu ne na wani labarin.
Aji huɗu, abubuwa masu haɗa ƙarfe da yawa
Akwai manyan nau'ikan ƙarfe guda huɗu na bakin ƙarfe:
austenitic
martensitic
ferritic
Duplex
Sunayen sun samo asali ne daga tsarin lu'ulu'u na ƙarfen da ake samu a yanayin zafin ɗaki. Idan aka yi zafi da ƙarfe mai ƙarancin carbon sama da digiri 912 na Celsius, ana sake tsara ƙwayoyin zarra na ƙarfe daga tsarin da ake kira ferrite a yanayin zafin ɗaki zuwa tsarin lu'ulu'u da ake kira austenite. Da zarar sun sanyaya, ƙwayoyin zarra suna komawa ga tsarinsu na asali, ferrite. Tsarin zafin jiki mai girma, austenite, ba shi da maganadisu, filastik kuma yana da ƙarancin ƙarfi da kuma juriya fiye da yanayin zafin ɗaki na ferrite.
Idan aka ƙara fiye da kashi 16% na chromium a cikin ƙarfe, tsarin crystalline na zafin ɗakin, ferrite, zai daidaita kuma ƙarfen ya ci gaba da kasancewa a cikin yanayin ferritic a kowane yanayin zafi. Don haka ana amfani da sunan ƙarfe mai ƙarfe ferritic a kan wannan tushen ƙarfe. Idan aka ƙara fiye da kashi 17% na chromium da 7% na nickel a cikin ƙarfe, tsarin crystalline mai zafi na ƙarfe, austenite, zai daidaita ta yadda zai ci gaba a kowane yanayin zafi daga mafi ƙasƙanci zuwa kusan narkewa.
Ana kiran bakin ƙarfe na Austenitic da nau'in 'chrome-nickel', kuma ƙarfen martensitic da ferritic galibi ana kiransu nau'ikan 'chrome madaidaiciya'. Wasu abubuwan haɗin ƙarfe da ake amfani da su a cikin ƙarfe na bakin ƙarfe da ƙarfe na walda suna aiki azaman masu daidaita austenite da sauransu azaman masu daidaita ferrite. Mafi mahimmancin masu daidaita austenite sune nickel, carbon, manganese da nitrogen. Masu daidaita ferrite sune chromium, silicon, molybdenum da niobium. Daidaita abubuwan haɗin yana sarrafa adadin ferrite a cikin ƙarfe na walda.
Ma'aunin Austenitic yana da sauƙin haɗawa da gamsuwa fiye da waɗanda ke ɗauke da ƙasa da kashi 5% na nickel. Haɗin walda da aka samar a cikin ƙarfe mai bakin austenitic suna da ƙarfi, masu ƙarfi da ƙarfi a yanayin waldansu. Ba sa buƙatar yin amfani da zafin da aka riga aka dumama ko kuma bayan walda. Ma'aunin Austenitic ya kai kusan kashi 80% na walda mai bakin ƙarfe, kuma wannan labarin gabatarwa ya fi mai da hankali sosai a kansu.
Tebur 1: Nau'in bakin ƙarfe da abubuwan da ke cikin chromium da nickel.
tstart{c,80%}
ad{Nau'i|% Chromium|% Nickel|Nau'in}
tdata{Austenitic|16 - 30%|8 - 40%|200, 300}
tdata{Martensitic|11 - 18%|0 - 5%|403, 410, 416, 420}
tdata{Ferritic|11 - 30%|0 - 4%|405, 409, 430, 422, 446}
tdata{Duplex|18 - 28%|4 - 8%|2205}
tsara{}
Yadda ake zaɓar ƙarfe mai cika bakin ƙarfe daidai
Idan kayan tushe a cikin faranti biyu iri ɗaya ne, ƙa'idar farko ta kasance, 'Fara da daidaita kayan tushe.' Wannan yana aiki da kyau a wasu lokuta; don haɗawa da Nau'in 310 ko 316, zaɓi Nau'in cikawa da ya dace.
Don haɗa kayan da ba su da kama da juna, bi wannan jagorar: 'zaɓi mai cikawa don ya dace da kayan da suka fi haɗa abubuwa.' Don haɗa 304 zuwa 316, zaɓi mai cikawa 316.
Abin takaici, 'ƙa'idar daidaitawa' tana da keɓancewa da yawa wanda mafi kyawun ƙa'ida ita ce, Duba teburin zaɓin ƙarfe mai cikawa. Misali, Nau'in 304 shine kayan tushe na bakin ƙarfe da aka fi sani, amma babu wanda ke bayar da na'urar lantarki ta Type 304.
Yadda ake walda Nau'in 304 bakin karfe ba tare da na'urar lantarki ta Type 304 ba
Don walda bakin Type 304, yi amfani da abin cika Type 308, domin ƙarin abubuwan haɗawa a cikin Type 308 za su fi daidaita yankin walda.
Duk da haka, 308L shi ma abin cikawa ne da aka yarda da shi. Sunan 'L' bayan kowane Nau'i yana nuna ƙarancin sinadarin carbon. Nau'in bakin karfe na 3XXL yana da sinadarin carbon na 0.03% ko ƙasa da haka, yayin da na yau da kullun na 3XX bakin karfe na iya samun matsakaicin sinadarin carbon na 0.08%.
Saboda cika nau'in L yana cikin rarrabuwa iri ɗaya da samfurin da ba L ba, masu ƙera za su iya, kuma ya kamata su yi la'akari sosai, ta amfani da cika nau'in L saboda ƙarancin sinadarin carbon yana rage haɗarin matsalolin tsatsa tsakanin granular. A zahiri, marubutan sun yi jayayya cewa cika nau'in L zai fi amfani idan masu ƙera kawai suka sabunta hanyoyin aikinsu.
Masu ƙera kayan da ke amfani da tsarin GMAW suma suna iya son yin la'akari da amfani da abin cika nau'in 3XXSi, domin ƙara silicon yana inganta jikewa. A cikin yanayi inda walda take da kambi mai tsayi ko mai kauri, ko kuma inda kududdufin walda bai ɗaure sosai a yatsun fillet ko haɗin gwiwa ba, amfani da na'urar lantarki ta Si Type GMAW na iya sassauta dutsen walda kuma ya haɓaka haɗuwa mafi kyau.
Idan akwai damuwa game da ruwan sama mai dauke da sinadarin carbide, yi la'akari da abin cika nau'in 347, wanda ke dauke da karamin adadin niobium.
Yadda ake haɗa bakin ƙarfe zuwa ƙarfen carbon
Wannan yanayi yana faruwa ne a aikace-aikace inda wani ɓangare na tsari yana buƙatar fuskar waje mai jure tsatsa wanda aka haɗa da sinadarin ƙarfe na carbon don rage farashi. Lokacin haɗa kayan tushe ba tare da abubuwan haɗawa zuwa kayan tushe tare da abubuwan haɗawa ba, yi amfani da abin cikawa mai yawa don narkewar ƙarfe a cikin walda ya daidaita ko ya fi ƙarfen tushe na bakin ƙarfe ƙarfi.
Don haɗa ƙarfen carbon zuwa Type 304 ko 316, da kuma don haɗa ƙarfen bakin ƙarfe daban-daban, yi la'akari da na'urar lantarki ta Type 309L don yawancin aikace-aikace. Idan ana son ƙara yawan Cr, yi la'akari da Type 312.
A matsayin gargaɗi, ƙarfen bakin ƙarfe na austenitic yana nuna ƙaruwar faɗaɗawa wanda ya fi na ƙarfen carbon da kusan kashi 50 cikin ɗari. Idan aka haɗa shi, bambancin ƙimar faɗaɗawa na iya haifar da tsagewa saboda matsin lamba na ciki sai dai idan an yi amfani da hanyar lantarki da walda da ta dace.
Yi amfani da hanyoyin tsaftacewa da suka dace na shirye-shiryen walda
Kamar yadda yake a sauran karafa, da farko a cire mai, mai, alamomi da datti da sinadarin da ba shi da sinadarin chlorine. Bayan haka, babban ƙa'idar shirya walda ta bakin karfe ita ce 'Guji gurɓatawa daga ƙarfen carbon don hana tsatsa.' Wasu kamfanoni suna amfani da gine-gine daban-daban don 'shagonsu na bakin karfe' da 'shagon carbon' don hana gurɓatawa.
Sanya ƙafafun niƙa da goga marasa bakin ƙarfe a matsayin 'babu bakin ƙarfe kawai' lokacin shirya gefuna don walda. Wasu hanyoyin suna buƙatar tsaftacewa inci biyu daga haɗin gwiwa. Shiri na haɗin gwiwa shi ma ya fi mahimmanci, domin rama rashin daidaiton da aka samu tare da sarrafa lantarki ya fi wahala fiye da ƙarfe mai carbon.
Yi amfani da hanyar tsaftace bayan walda don hana tsatsa
Da farko, ku tuna abin da ke sa bakin ƙarfe ya yi bakin ƙarfe: martanin chromium tare da iskar oxygen don samar da wani Layer mai kariya na chromium oxide a saman kayan. Tsatsa mai bakin ƙarfe saboda ruwan carbide (duba ƙasa) kuma saboda tsarin walda yana dumama ƙarfen walda har zuwa inda ferritic oxide zai iya samuwa a saman walda. Idan aka bar shi a cikin yanayin walda, walda mai kyau zai iya nuna 'wuraren tsatsa na kekunan kekuna' a iyakokin yankin da zafi ya shafa cikin ƙasa da awanni 24.
Domin sabon Layer na chromium oxide mai tsabta ya iya gyara yadda ya kamata, bakin karfe yana buƙatar tsaftacewa bayan walda ta hanyar gogewa, tsintsa, niƙa ko gogewa. Kuma, yi amfani da injin niƙa da buroshi da aka keɓe don aikin.
Me yasa waya ta walda ta bakin karfe take maganadisu?
Bakin ƙarfe mai cikakken austenitic ba shi da wani sinadari na maganadisu. Duk da haka, yanayin zafi na walda yana haifar da babban hatsi a cikin ƙananan tsarin, wanda ke haifar da walda ta zama mai saurin kamuwa da tsagewa. Don rage saurin kamuwa da tsagewa mai zafi, masana'antun lantarki suna ƙara abubuwan haɗin gwiwa, gami da ferrite. Matakin ferrite yana sa ƙwayoyin austenitic su fi kyau, don haka walda ta zama mai juriya ga tsagewa.
Magnet ba zai manne a kan wani abu mai kama da bakin ƙarfe na austenitic ba, amma mutumin da ke riƙe da maganadisu zai iya jin ɗan jan hankali saboda ferrite ɗin da aka riƙe. Abin takaici, wannan yana sa wasu masu amfani su yi tunanin cewa an yi wa samfurin su lakabin da bai dace ba ko kuma suna amfani da ƙarfen cikawa da bai dace ba (musamman idan sun yage lakabin daga kwandon waya).
Daidaiton adadin ferrite a cikin na'urar lantarki ya dogara ne da zafin aiki na aikace-aikacen. Misali, yawan ferrite yana sa walda ta rasa tauri a ƙananan yanayin zafi. Don haka, na'urar cika bututun LNG ta Type 308 tana da lambar ferrite tsakanin 3 da 6, idan aka kwatanta da lambar ferrite ta 8 don na'urar cika nau'in 308 na yau da kullun. A takaice, ƙarfe mai cika na iya kama da juna da farko, amma ƙananan bambance-bambance a cikin abun da ke ciki suna da mahimmanci.
Akwai wata hanya mai sauƙi ta walda ƙarfe masu duplex marasa ƙarfi?
Yawanci, ƙarfe mai kauri biyu yana da tsarin microstructure wanda ya ƙunshi kusan kashi 50% na ferrite da kashi 50% na austenite. A taƙaice, ferrite yana ba da ƙarfi mai yawa da kuma juriya ga tsagewar datti yayin da austenite ke ba da ƙarfi mai kyau. Matakai biyu a haɗe suna ba ƙarfe mai kauri biyu kyawawan halaye. Akwai nau'ikan ƙarfe mai kauri biyu, waɗanda suka fi yawa sune Type 2205; wannan ya ƙunshi kashi 22% na chromium, kashi 5% na nickel, kashi 3% na molybdenum da kuma kashi 0.15% na nitrogen.
Lokacin walda ƙarfe mai duplex, matsaloli na iya tasowa idan ƙarfen walda yana da ferrite da yawa (zafin da ke fitowa daga baka yana sa ƙwayoyin halittar su shirya kansu a cikin matrix na ferrite). Don ramawa, ƙarfe masu cikawa suna buƙatar haɓaka tsarin austenitic tare da babban abun ciki na gami, yawanci nickel 2 zuwa 4% fiye da ƙarfe na tushe. Misali, waya mai juzu'i don walda Type 2205 na iya samun nickel 8.85%.
Yawan sinadarin ferrite da ake so zai iya kasancewa daga kashi 25 zuwa 55% bayan walda (amma zai iya zama mafi girma). Lura cewa dole ne saurin sanyaya ya kasance mai jinkirin da zai ba da damar austenite ya gyara, amma ba mai jinkirin da zai haifar da matakai na ƙarfe ba, kuma ba mai sauri da zai haifar da ƙarin ferrite a yankin da zafi ya shafa ba. Bi hanyoyin da masana'anta suka ba da shawarar don aikin walda da ƙarfen cika da aka zaɓa.
Daidaita sigogi lokacin walda bakin karfe
Ga masu ƙera kayayyaki waɗanda ke daidaita sigogi akai-akai (ƙarfin lantarki, amperage, tsawon baka, inductance, faɗin bugun jini, da sauransu) lokacin walda bakin ƙarfe, babban abin da ke haifar da hakan shine rashin daidaiton abun da ke cikin ƙarfe mai cikewa. Ganin mahimmancin abubuwan da ke haɗa ƙarfe, bambancin da ke tsakanin nau'ikan sinadarai na iya yin tasiri sosai kan aikin walda, kamar rashin danshi ko wahalar sakin slag. Bambancin diamita na lantarki, tsaftar saman, siminti da helix suma suna shafar aiki a aikace-aikacen GMAW da FCAW.
Sarrafa ruwan sama mai sarrafa carbide a cikin bakin karfe na austenitic
A yanayin zafi da ke tsakanin digiri 426-871 na Celsius, sinadarin carbon da ya wuce kashi 0.02% yana ƙaura zuwa iyakokin hatsi na tsarin austenitic, inda yake amsawa da chromium don samar da chromium carbide. Idan chromium ya haɗu da carbon, ba ya samuwa don juriya ga tsatsa. Idan aka fallasa shi ga muhallin da ke lalata iska, tsatsa tsakanin granular na iya haifar da lalacewa, wanda ke ba da damar cinye iyakokin hatsi.
Domin sarrafa ruwan sama na carbide, a kiyaye yawan sinadarin carbon gwargwadon iyawa (mafi girman kashi 0.04%) ta hanyar walda da ƙananan electrodes na carbon. Haka kuma ana iya ɗaure carbon ta hanyar niobium (wanda a da columbium ne) da titanium, waɗanda ke da ƙarfi ga carbon fiye da chromium. An yi nau'in electrodes na 347 don wannan dalili.
Yadda ake shirya tattaunawa game da zaɓin ƙarfe mai cikawa
Aƙalla, tattara bayanai kan yadda ake amfani da ɓangaren da aka haɗa a ƙarshen amfani da shi, gami da yanayin sabis (musamman yanayin zafi na aiki, fallasa ga abubuwan da ke lalata da matakin juriyar tsatsa) da kuma tsawon lokacin sabis ɗin da ake so. Bayani kan halayen injina da ake buƙata a yanayin aiki yana taimakawa sosai, gami da ƙarfi, tauri, jurewa da gajiya.
Yawancin manyan masana'antun lantarki suna ba da littattafan jagora don zaɓar ƙarfe mai cikawa, kuma marubutan ba za su iya jaddada wannan batu ba: tuntuɓi jagorar aikace-aikacen ƙarfe mai cikawa ko tuntuɓi ƙwararrun masana'antar. Suna nan don taimakawa wajen zaɓar madaidaicin lantarki na bakin ƙarfe.
Don ƙarin bayani game da ƙarfen cika bakin ƙarfe na TYUE da kuma tuntuɓar ƙwararrun kamfanin don neman shawara, ziyarci www.tyuelec.com.
Lokacin Saƙo: Disamba-23-2022