Kun tabbatar da cewa an ƙera sassan bisa ga ƙa'idodi. Yanzu ku tabbata kun ɗauki matakai don kare waɗannan sassan a cikin yanayin da abokan cinikin ku ke tsammani. #base
Passivation ya kasance muhimmin mataki wajen ƙara juriya ga tsatsa na sassa da kayan haɗin da aka ƙera daga bakin ƙarfe. Wannan na iya kawo bambanci tsakanin aiki mai gamsarwa da gazawar da wuri. Rashin daidaiton passivation na iya haifar da tsatsa.
Passivation wata dabara ce ta bayan ƙera kayan da ke ƙara juriya ga tsatsa na ƙarfen bakin ƙarfe da aka yi aikin da shi. Wannan ba rage girman ko fenti ba ne.
Babu wata yarjejeniya kan ainihin hanyar da passivation ke aiki. Amma an san tabbas cewa akwai wani fim mai kariya daga oxide a saman bakin karfe mai passivated. Ana cewa wannan fim ɗin da ba a gani siriri ne sosai, ƙasa da inci 0.0000001 kauri, wanda yake kusan kashi 1/100,000 na kauri na gashin ɗan adam!
Sashen bakin ƙarfe mai tsabta, sabo da aka yi masa injina, gogewa, ko kuma wanda aka yi masa tsami zai sami wannan fim ɗin oxide ta atomatik saboda fallasa shi ga iskar oxygen ta yanayi. A ƙarƙashin yanayi mai kyau, wannan Layer ɗin oxide mai kariya ya rufe dukkan saman ɓangaren gaba ɗaya.
Amma a aikace, gurɓatattun abubuwa kamar dattin masana'anta ko barbashi na ƙarfe daga kayan aikin yankewa na iya shiga saman sassan bakin ƙarfe yayin sarrafawa. Idan ba a cire su ba, waɗannan abubuwan waje na iya rage tasirin fim ɗin kariya na asali.
A lokacin da ake yin injin, ana iya cire alamun ƙarfe marasa amfani daga kayan aikin sannan a mayar da su zuwa saman aikin ƙarfen bakin ƙarfe. A wasu lokuta, siririn tsatsa na iya bayyana a ɓangaren. A zahiri, wannan shine tsatsar ƙarfen kayan aikin, ba ƙarfen tushe ba. Wani lokaci fasawar ƙwayoyin ƙarfe da aka saka daga kayan aikin yankewa ko samfuran tsatsa na iya lalata ɓangaren da kansa.
Hakazalika, ƙananan ƙwayoyin ƙarfe na dattin ƙarfe na iya mannewa a saman ɓangaren. Ko da yake ƙarfen na iya bayyana a yanayin da ya ƙare, bayan an fallasa shi ga iska, ƙwayoyin ƙarfe marasa ganuwa na iya haifar da tsatsa a saman.
Sulfide da aka fallasa suma na iya zama matsala. Ana yin su ta hanyar ƙara sulfur a cikin bakin ƙarfe don inganta injinin. Sulfide yana ƙara ƙarfin haɗin don samar da guntu yayin aikin ƙera, wanda za'a iya cire shi gaba ɗaya daga kayan aikin yankewa. Idan sassan ba su da kyau, sulfide na iya zama wurin farawa na tsatsa saman samfuran masana'antu.
A duka yanayi biyu, ana buƙatar passivation don haɓaka juriyar tsatsa ta halitta na bakin ƙarfe. Yana kawar da gurɓatattun abubuwa kamar ƙwayoyin ƙarfe da ƙwayoyin ƙarfe a cikin kayan aikin yankewa waɗanda zasu iya yin tsatsa ko zama wurin fara tsatsa. Passivation kuma yana cire sulphides da aka samu a saman ƙarfen bakin ƙarfe da aka yanke.
Tsarin matakai biyu yana ba da mafi kyawun juriya ga tsatsa: 1. Tsaftacewa, babban tsari, amma wani lokacin ana yin watsi da shi 2. Wanka mai acid ko passivation.
Tsaftacewa ya kamata ya zama abin fifiko koyaushe. Dole ne a tsaftace saman da mai, ruwan sanyaya ko wasu tarkace sosai don tabbatar da juriyar tsatsa. Ana iya goge tarkacen injin ko wasu datti na masana'anta a hankali daga ɓangaren. Ana iya amfani da na'urorin rage mai ko masu tsaftacewa na kasuwanci don cire mai ko na'urorin sanyaya ruwa. Abubuwan da ba na waje kamar su thermal oxides na iya buƙatar cire su ta hanyoyi kamar niƙa ko tsinken tsinkewa.
Wani lokaci mai aikin injin zai iya tsallake tsaftacewa ta asali, yana tunanin cewa tsaftacewa da passivation za su faru a lokaci guda, kawai ta hanyar nutsar da ɓangaren da aka mai a cikin baho mai acid. Ba zai faru ba. Akasin haka, mai da ya gurɓata yana amsawa da acid don samar da kumfa iska. Waɗannan kumfa suna taruwa a saman aikin kuma suna tsoma baki ga passivation.
Mafi muni ma, gurɓatar maganin passivation, wanda wani lokacin ke ɗauke da yawan sinadarin chloride, na iya haifar da "walƙiya". Sabanin samar da fim ɗin oxide da ake so tare da saman da ke da sheƙi, tsabta, da juriya ga tsatsa, walƙiyar walƙiya na iya haifar da mummunan ɓarna ko duhun saman - lalacewa a saman da aka tsara passivation don ingantawa.
Ana kashe sassan bakin ƙarfe masu kama da Martensitic [magnetic, masu juriya ga tsatsa, ƙarfin samarwa har zuwa kusan psi dubu 280 (1930 MPa)] a yanayin zafi mai yawa sannan a daidaita su don samar da taurin da ake so da halayen injiniya. Ana iya magance ruwan sama mai ƙarfi (wanda ke da ƙarfi da juriya ga tsatsa fiye da matakan martensitic) ta hanyar maganin ruwa, a yi masa injin da kansa, a tsufa a ƙananan zafin jiki, sannan a gama.
A wannan yanayin, dole ne a tsaftace ɓangaren sosai da man shafawa ko mai tsaftacewa kafin a yi amfani da shi a zafin jiki don cire duk wani alamar ruwan da aka yanke. In ba haka ba, ruwan da ke sanyaya da ya rage a ɓangaren na iya haifar da yawan iskar shaka. Wannan yanayin na iya haifar da tarkace a kan ƙananan sassa bayan an cire shi da hanyoyin acid ko abrasive. Idan aka bar ruwan sanyaya a kan sassa masu sheƙi, kamar a cikin tanda mai tsabta ko a cikin yanayi mai kariya, za a iya samun carburization na saman, wanda ke haifar da asarar juriya ga tsatsa.
Bayan tsaftacewa sosai, ana iya nutsar da sassan bakin karfe a cikin wani wurin wanka mai ɗauke da sinadarin acid. Ana iya amfani da kowace hanya guda uku - passivation tare da nitric acid, passivation tare da nitric acid tare da sodium dichromate, da passivation tare da citric acid. Wace hanya za a yi amfani da ita ta dogara ne da matakin bakin karfe da kuma ƙa'idodin karɓuwa da aka ƙayyade.
Ana iya amfani da ƙarin nau'ikan nickel chromium masu jure tsatsa a cikin baho na nitric acid na 20% (v/v) (Hoto na 1). Kamar yadda aka nuna a cikin tebur, ana iya amfani da ƙarfe marasa juriya ta hanyar ƙara sodium dichromate a cikin baho na nitric acid don sa maganin ya fi oxidizing kuma ya sami damar samar da fim mai jure tsatsa a saman ƙarfe. Wani zaɓi don maye gurbin nitric acid da sodium chromate shine ƙara yawan nitric acid zuwa 50% ta hanyar girma. Duk da ƙara sodium dichromate da yawan nitric acid yana rage yiwuwar walƙiya mara so.
Tsarin passivation na ƙarfen bakin ƙarfe da za a iya kera (wanda kuma aka nuna a Hoto na 1) ya ɗan bambanta da tsarin passivation na ƙarfen bakin ƙarfe da ba za a iya kera ba. Wannan saboda a lokacin passivation a cikin wanka na nitric acid ana cire wasu ko duk sulfides masu ɗauke da sulfur da za a iya kera, wanda ke haifar da rashin daidaituwar microscopic a saman aikin.
Ko da wanke ruwa yadda ya kamata zai iya barin ragowar acid a cikin waɗannan abubuwan da suka rage bayan an cire shi. Wannan acid ɗin zai kai hari kan saman ɓangaren idan ba a cire shi ba ko kuma an cire shi.
Domin inganta ingancin amfani da bakin karfe mai sauƙin amfani da shi, Carpenter ya ƙirƙiro tsarin AAA (Alkaline-Acid-Alkaline), wanda ke kawar da ragowar acid. Ana iya kammala wannan hanyar passivation cikin ƙasa da awanni 2. Ga tsarin mataki-mataki:
Bayan an shafa mai, a jiƙa sassan a cikin ruwan sodium hydroxide mai kashi 5% a zafin 160°F zuwa 180°F (71°C zuwa 82°C) na tsawon mintuna 30. Sannan a wanke sassan sosai a cikin ruwa. Sannan a nutsar da sashin na tsawon mintuna 30 a cikin ruwan nitric acid mai kashi 20% (v/v) wanda ke ɗauke da sodium dichromate mai girman 3 oz/gal (22 g/l) a zafin 120°F zuwa 140°F (49°C) zuwa 60°C.) Bayan cire sashin daga wanka, a wanke shi da ruwa, sannan a nutsar da shi a cikin ruwan sodium hydroxide na tsawon mintuna 30. A sake kurkure sashin da ruwa sannan a busar da shi, a kammala hanyar AAA.
Rashin sinadarin citric acid yana ƙara zama ruwan dare a tsakanin masana'antun da ke son guje wa amfani da ma'adanai ko mafita waɗanda ke ɗauke da sodium dichromate, da kuma matsalolin zubar da shi da kuma ƙara matsalolin tsaro da ke tattare da amfani da shi. Ana ɗaukar Citric acid a matsayin wanda ba ya cutar da muhalli ta kowace fuska.
Duk da cewa sinadarin citric acid yana da fa'idodi masu kyau ga muhalli, shagunan da suka yi nasara wajen amfani da sinadarin inorganic acid passivation kuma ba su da wata damuwa game da tsaro na iya son ci gaba da aiki. Idan waɗannan masu amfani suna da shago mai tsafta, kayan aikin suna cikin yanayi mai kyau da tsafta, injin sanyaya ba shi da ma'ajiyar ƙarfe, kuma tsarin yana samar da sakamako mai kyau, ƙila ba za a buƙaci canji ba.
An gano cewa rashin amfani da sinadarin citric acid a cikin wanka yana da amfani ga nau'ikan ƙarfe masu yawa, gami da nau'ikan ƙarfe daban-daban, kamar yadda aka nuna a Hoto na 2. Don saukaka amfani, Hoto na 2. 1 ya haɗa da hanyar gargajiya ta rashin amfani da sinadarin nitric acid. Lura cewa an bayyana tsoffin tsarin nitric acid a matsayin kashi-kashi ta hanyar girma, yayin da sabbin yawan sinadarin citric acid ana bayyana su a matsayin kashi-kashi ta hanyar taro. Yana da mahimmanci a lura cewa lokacin yin waɗannan hanyoyin, daidaita lokacin jiƙa, zafin wanka, da yawan amfani yana da mahimmanci don guje wa "walƙiya" da aka bayyana a sama.
Rashin aiki ya bambanta dangane da abun ciki na chromium da halayen sarrafawa na kowane nau'in. Lura da ginshiƙai na Tsarin 1 ko Tsarin 2. Kamar yadda aka nuna a Hoto na 3, Tsarin 1 yana da ƙananan matakai fiye da Tsarin 2.
Gwaje-gwajen dakin gwaje-gwaje sun nuna cewa tsarin passivation na citric acid ya fi saurin "tafasa" fiye da tsarin nitric acid. Abubuwan da ke taimakawa wajen wannan harin sun haɗa da yawan zafin wanka, tsawon lokacin jiƙawa, da gurɓatar wanka. Kayayyakin da aka samo daga citric acid waɗanda ke ɗauke da hana tsatsa da sauran ƙari kamar su abubuwan da ake ƙarawa a jika suna samuwa a kasuwa kuma an ruwaito cewa suna rage saurin "tsatsagewa".
Zaɓin ƙarshe na hanyar wucewa zai dogara ne akan ƙa'idodin karɓa da abokin ciniki ya gindaya. Duba ASTM A967 don ƙarin bayani. Ana iya samunsa a www.astm.org.
Sau da yawa ana yin gwaje-gwaje don tantance saman sassan da aka cire. Tambayar da za a amsa ita ce "Shin passivation yana cire ƙarfe kyauta kuma yana inganta juriyar tsatsa na ƙarfe don yankewa ta atomatik?"
Yana da mahimmanci cewa hanyar gwajin ta yi daidai da ajin da ake tantancewa. Jarabawar da ta yi tsauri sosai ba za ta wuce kayan aiki masu kyau ba, yayin da jarrabawar da ta yi rauni sosai za ta wuce sassan da ba su da gamsarwa.
Ana iya kimanta ƙarfe mai laushi da na bakin ƙarfe mai sassauƙa 400 a cikin ɗaki mai iya kiyaye danshi 100% (samfurin ya jike) na tsawon awanni 24 a zafin jiki na 95°F (35°C). Sashen giciye galibi shine saman da ya fi mahimmanci, musamman don matakan yankewa kyauta. Ɗaya daga cikin dalilan wannan shine cewa ana jan sulphide zuwa alkiblar injin a duk faɗin wannan saman.
Ya kamata a sanya saman abubuwa masu mahimmanci a sama, amma a kusurwar digiri 15 zuwa 20 daga tsaye, don ba da damar asarar danshi. Kayan da aka yi amfani da su yadda ya kamata ba zai yi tsatsa ba, kodayake ƙananan tabo na iya bayyana a kai.
Ana iya kimanta ma'aunin bakin ƙarfe na Austenitic ta hanyar gwajin danshi. A cikin wannan gwajin, ya kamata a sami digo na ruwa a saman samfurin, wanda ke nuna babu ƙarfe ta hanyar kasancewar kowane tsatsa.
Tsarin Passivation na ƙarfe masu amfani da hannu da na atomatik a cikin maganin citric ko nitric acid yana buƙatar matakai daban-daban. A kan siffa ta 3 da ke ƙasa yana ba da cikakkun bayanai kan zaɓin tsari.
(a) Daidaita pH da sodium hydroxide. (b) Duba hoto na 3(c) Na2Cr2O7 shine 3 oz/gal (22 g/L) sodium dichromate a cikin 20% nitric acid. Madadin wannan cakuda shine 50% nitric acid ba tare da sodium dichromate ba.
Hanya mafi sauri ita ce amfani da ASTM A380, Tsarin Aiki na Tsaftacewa, Rage Tsaftacewa, da Rage Tsaftace Sassan Bakin Karfe, Kayan Aiki, da Tsarin. Gwajin ya haɗa da goge ɓangaren da maganin jan ƙarfe sulfate/sulfuric acid, ajiye shi a jika na tsawon mintuna 6, da kuma lura da farantin jan ƙarfe. A madadin haka, ana iya nutsar da ɓangaren a cikin maganin na tsawon mintuna 6. Idan ƙarfe ya narke, farantin jan ƙarfe yana faruwa. Wannan gwajin bai shafi saman sassan sarrafa abinci ba. Hakanan, bai kamata a yi amfani da shi akan ƙarfe martensitic jerin 400 ko ƙananan ƙarfe ferritic chromium ba saboda sakamakon ƙarya na iya faruwa.
A tarihi, an yi amfani da gwajin fesa gishiri na kashi 5% a zafin jiki na 95°F (35°C) don tantance samfuran da aka yi amfani da su wajen fesawa. Wannan gwajin ya yi tsauri ga wasu nau'ikan kuma gabaɗaya ba a buƙatar shi don tabbatar da ingancin passivation.
A guji amfani da sinadarin chloride mai yawa, wanda zai iya haifar da fashewa mai haɗari. Yi amfani da ruwa mai inganci kawai tare da ƙasa da sassa 50 a kowace miliyan (ppm) chloride duk lokacin da zai yiwu. Ruwan famfo yawanci ya isa, kuma a wasu lokuta yana iya jure wa har zuwa ɗaruruwan sassa a kowace miliyan na chloride.
Yana da muhimmanci a riƙa maye gurbin wanka akai-akai domin kada a rasa ƙarfin passivation, wanda zai iya haifar da walƙiya da lalacewar sassa. Dole ne a kula da wanka a yanayin zafi mai kyau, domin yanayin zafi mara tsari na iya haifar da tsatsa a yankin.
Yana da mahimmanci a bi takamaiman jadawalin canza mafita yayin manyan ayyukan samarwa don rage yuwuwar gurɓatawa. An yi amfani da samfurin sarrafawa don gwada ingancin wanka. Idan an kai wa samfurin hari, lokaci ya yi da za a maye gurbin wanka.
Lura cewa wasu injuna suna samar da bakin karfe ne kawai; suna amfani da irin wannan ruwan sanyi da aka fi so don yanke bakin karfe banda duk sauran karafa.
Ana kera sassan DO rack daban-daban domin gujewa hulɗar ƙarfe da ƙarfe. Wannan yana da mahimmanci musamman ga injinan ƙarfe kyauta, domin ana buƙatar hanyoyin tsaftacewa da kuma fitar da ruwa mai sauƙi don yaɗa samfuran tsatsa na sulfide da kuma hana samuwar aljihunan acid.
Kada a yi amfani da sassan ƙarfe masu ƙarfe masu kauri ko nitride. Juriyar tsatsa na sassan da aka yi wa magani ta wannan hanyar na iya raguwa har ta kai ga lalacewa a cikin baho mai kauri.
Kada a yi amfani da kayan aikin ƙarfe masu ƙarfe a yanayin aiki wanda ba shi da tsafta musamman. Ana iya guje wa guntun ƙarfe ta amfani da kayan aikin carbide ko yumbu.
A sani cewa tsatsa na iya faruwa a cikin wurin wanka idan ba a yi maganin zafi yadda ya kamata ba. Dole ne a taurare ma'aunin Martensitic tare da yawan carbon da chromium don juriya ga tsatsa.
Ana yin amfani da passivation bayan an yi amfani da shi a yanayin zafi wanda ke kiyaye juriya ga tsatsa.
Kada ku yi watsi da yawan sinadarin nitric acid a cikin baho mai narkewa. Ya kamata a yi bincike akai-akai ta amfani da tsarin titration mai sauƙi da Carpenter ya ba da shawara. Kada a yi amfani da ƙarfe fiye da ɗaya a lokaci guda. Wannan yana hana rikicewa mai tsada kuma yana hana halayen galvanic.
Game da Marubutan: Terry A. DeBold ƙwararren masani ne kan bincike da haɓaka ƙarfe na ƙarfe, kuma James W. Martin ƙwararren masani ne kan sarrafa ƙarfe a kamfanin Carpenter Technology Corp.(Reading, Pennsylvania).
Nawa ne? Nawa ne sarari nake buƙata? Waɗanne matsalolin muhalli zan fuskanta? Yaya tsayin koyo yake? Menene ainihin anodizing? Ga amsoshin tambayoyin farko na masters game da anodizing cikin gida.
Samun sakamako mai inganci da daidaito daga tsarin niƙa mara tsakiya yana buƙatar fahimta ta asali. Yawancin matsalolin aikace-aikacen da ke da alaƙa da niƙa mara tsakiya suna tasowa ne daga rashin fahimtar muhimman abubuwa. Wannan labarin ya bayyana dalilin da yasa tsarin rashin hankali yake aiki da kuma yadda za a yi amfani da shi yadda ya kamata a cikin taron bitar ku.