Kun tabbatar da cewa an kera sassan don ƙayyadaddun bayanai.Yanzu ka tabbata ka ɗauki matakai don kare waɗannan sassa a cikin yanayin da abokan cinikin ku suke tsammani.#base
Passivation ya kasance muhimmin mataki na haɓaka juriya na lalata sassa da taruka da aka yi daga bakin karfe.Wannan na iya yin bambanci tsakanin aiki mai gamsarwa da gazawar da bai kai ba.Rashin wucewa mara kyau na iya haifar da lalata.
Passivation dabara ce ta bayan ƙirƙira wacce ke haɓaka juriyar juriya ta bakin karfe daga abin da aka yi aikin.Wannan ba ragewa bane ko zanen.
Babu yarjejeniya kan ainihin hanyar da wucewa ke aiki.Amma an san tabbas cewa akwai fim ɗin kariya na oxide akan saman bakin karfe mai wucewa.Wannan fim din da ba a iya gani an ce yana da sirara sosai, kasa da inci 0.0000001, wanda ya kai kusan 1/100,000 na kaurin gashin dan Adam!
Tsaftace, sabon injina, gogewa, ko ɓangaren bakin karfe da aka ɗora zai sami wannan fim ɗin oxide ta atomatik saboda fallasa ga iskar oxygen.A ƙarƙashin kyakkyawan yanayi, wannan Layer oxide mai kariya ya rufe gaba ɗaya duk saman ɓangaren.
A aikace, duk da haka, gurɓatattun abubuwa kamar dattin masana'anta ko ɓangarorin ƙarfe daga yankan kayan aikin na iya samun saman sassan bakin karfe yayin sarrafawa.Idan ba a cire su ba, waɗannan jikin waje na iya rage tasirin fim ɗin kariya na asali.
A lokacin machining, burbushin baƙin ƙarfe kyauta za a iya cire daga kayan aiki da kuma canjawa wuri zuwa saman bakin karfe workpiece.A wasu lokuta, tsatsa na bakin ciki na iya bayyana a ɓangaren.A gaskiya ma, wannan shine lalata kayan aikin karfe, ba karfen tushe ba.Wani lokaci fashewa daga ɓangarori na ƙarfe da aka haɗa daga kayan aikin yankan ko samfuran lalatarsu na iya lalata sashin da kansa.
Hakazalika, ƙananan barbashi na datti na ƙarfe na ƙarfe na iya mannewa saman ɓangaren.Ko da yake karfen na iya fitowa da kyalli a yanayin da ya gama, bayan fallasa iska, barbashi na baƙin ƙarfe da ba a iya gani zai iya haifar da tsatsa.
Sulfides da aka fallasa suma na iya zama matsala.Ana yin su ta hanyar ƙara sulfur zuwa bakin karfe don inganta injina.Sulfides suna ƙara ƙarfin haɗin gwiwa don samar da kwakwalwan kwamfuta a lokacin machining, wanda za'a iya cire shi gaba daya daga kayan aikin yankan.Idan sassan ba su wuce yadda ya kamata ba, sulfides na iya zama wurin farawa don lalata samfuran masana'antu.
A kowane hali, ana buƙatar wucewa don haɓaka juriya na lalata na bakin karfe.Yana kawar da gurɓataccen ƙasa kamar ƙwayoyin ƙarfe da baƙin ƙarfe a cikin kayan aikin yankan waɗanda zasu iya haifar da tsatsa ko zama wurin farawa don lalata.Passivation kuma yana kawar da sulphides da aka samu a saman buɗaɗɗen bakin karfe gami.
Hanya na mataki biyu yana ba da mafi kyawun juriya na lalata: 1. Tsaftacewa, babban hanya, amma wani lokacin watsi 2. Acid wanka ko passivation.
Tsaftacewa ya kamata koyaushe ya zama fifiko.Dole ne a share fage sosai daga maiko, mai sanyaya ko wasu tarkace don tabbatar da ingantacciyar juriyar lalata.Za'a iya goge tarkacen injina ko sauran dattin masana'anta a hankali daga sashin.Ana iya amfani da na'urar rage ƙorafi na kasuwanci ko masu tsaftacewa don cire mai sarrafa mai ko sanyaya.Baƙi kamar su thermal oxides na iya buƙatar cire su ta hanyoyi kamar niƙa ko tsintsa.
Wani lokaci ma'aikacin na'ura na iya tsallake tsaftacewa na asali, da kuskuren yarda cewa tsaftacewa da wucewa za su faru a lokaci guda, ta hanyar nutsar da ɓangaren mai a cikin wanka na acid.Ba zai faru ba.Akasin haka, gurɓataccen mai yana amsawa da acid don samar da kumfa.Wadannan kumfa suna tattarawa a kan farfajiyar aikin kuma suna tsoma baki tare da wucewa.
Mafi muni har yanzu, gurɓatar hanyoyin wucewa, wanda wani lokaci ya ƙunshi babban adadin chlorides, na iya haifar da "flash".Ya bambanta da samar da fim ɗin oxide da ake so tare da haske, mai tsabta, farfajiya mai jurewa, walƙiya filasha na iya haifar da matsanancin etching ko baƙar fata na saman-lalacewa a cikin farfajiyar da aka tsara wucewa don ingantawa.
Martensitic bakin karfe sassa [magnetic, matsakaici lalata resistant, samar da ƙarfi zuwa kusan 280 dubu psi (1930 MPa)] ana quenched a high yanayin zafi sa'an nan kuma fushi don samar da ake so taurin da inji Properties.Hazo mai taurare gami (waɗanda ke da mafi kyawun ƙarfi da juriya na lalata fiye da maki na martensitic) ana iya magance su, an yi wani yanki na injin, tsufa a ƙananan yanayin zafi, sannan a gama.
A wannan yanayin, dole ne a tsabtace ɓangaren da kyau tare da na'urar bushewa ko mai tsabta kafin maganin zafi don cire duk wani alamar yankan ruwa.In ba haka ba, coolant da ya rage a bangaren na iya haifar da wuce haddi.Wannan yanayin na iya haifar da hakora a kan ƙananan sassa bayan an lalata su tare da acid ko hanyoyin abrasive.Idan an bar coolant akan sassa masu taurare masu sheki, kamar a cikin tanderu ko a cikin yanayi mai karewa, carburization na saman na iya faruwa, yana haifar da asarar juriyar lalata.
Bayan tsaftacewa sosai, sassan bakin karfe za a iya nutsar da su a cikin wankan acid mai wucewa.Ana iya amfani da kowane ɗayan hanyoyin guda uku - passivation tare da acid nitric, passivation tare da nitric acid tare da sodium dichromate, da passivation tare da citric acid.Wace hanya za a yi amfani da ita ya dogara da darajar bakin karfe da ƙayyadaddun ka'idojin karɓa.
Ƙarin makin nickel chromium mai jure lalata ana iya wucewa a cikin wankan nitric acid na 20% (v/v) (Hoto na 1).Kamar yadda aka nuna a cikin tebur, ƙananan bakin karfe za a iya wucewa ta hanyar ƙara sodium dichromate zuwa wanka na nitric acid don sa maganin ya fi oxidizing kuma ya iya samar da fim mai wucewa a saman karfe.Wani zaɓi don maye gurbin acid nitric da sodium chromate shine ƙara yawan nitric acid zuwa 50% ta girma.Duka ƙari na sodium dichromate da mafi girma na nitric acid suna rage yiwuwar walƙiya maras so.
The passivation hanya na machinable bakin karfe (wanda kuma aka nuna a cikin siffa 1) ne dan kadan daban-daban daga hanya na mara-machinable bakin karfe maki.Wannan shi ne saboda lokacin wucewa a cikin wanka na nitric acid ana cire wasu ko duk na'urorin sulfur mai ɗauke da sulfide, suna haifar da inhomogeneities na microscopic a saman kayan aikin.
Hatta wanke ruwa mai tasiri na yau da kullun na iya barin ragowar acid a cikin waɗannan katsewar bayan wucewa.Wannan acid zai kai hari a saman sashin idan ba a cire shi ba ko cire shi.
Don ingantaccen wucewa na bakin karfe mai sauƙi-zuwa inji, Carpenter ya haɓaka tsarin AAA (Alkalin-Acid-Alkaline), wanda ke kawar da ragowar acid.Ana iya kammala wannan hanyar wucewa cikin ƙasa da sa'o'i 2.Ga tsarin mataki-mataki:
Bayan raguwa, jiƙa sassa a cikin 5% sodium hydroxide bayani a 160 ° F zuwa 180 ° F (71 ° C zuwa 82 ° C) na minti 30.Sa'an nan kuma kurkura sassan sosai a cikin ruwa.Sannan a nutsar da bangaren na tsawon mintuna 30 a cikin maganin nitric acid na 20% (v/v) mai dauke da 3 oz/gal (22 g/l) sodium dichromate a 120°F zuwa 140°F (49°C) zuwa 60°C.) Bayan an cire sashin daga wanka, sai a wanke shi da ruwa, sannan a nutsar da shi a cikin maganin sodium hydroxide na minti 30.A sake wanke ɓangaren da ruwa kuma a bushe, kammala hanyar AAA.
Citric acid passivation yana ƙara zama sananne tare da masana'antun da suke so su guje wa amfani da acid acid ko mafita dauke da sodium dichromate, kazalika da matsalolin zubar da damuwa da damuwa na aminci da ke hade da amfani da su.Ana ɗaukar Citric acid a matsayin abokantaka ta kowane fanni.
Duk da yake citric acid passivation yana ba da fa'idodin muhalli masu ban sha'awa, shagunan da suka yi nasara tare da wucewar acid inorganic kuma ba su da damuwa na tsaro na iya so su ci gaba da tafiya.Idan waɗannan masu amfani suna da kantin sayar da tsabta, kayan aiki suna cikin yanayi mai kyau da tsabta, mai sanyaya ba shi da ma'auni na masana'anta, kuma tsarin yana samar da sakamako mai kyau, ƙila ba za a sami ainihin buƙatar canji ba.
Citric acid bath passivation an gano yana da amfani ga nau'o'in nau'in bakin karfe, ciki har da nau'o'in nau'o'in nau'in nau'in karfe, kamar yadda aka nuna a cikin Hoto 2. Don dacewa, Hoto 2. 1 ya haɗa da hanyar gargajiya ta hanyar wucewa tare da nitric acid.Lura cewa tsoffin tsarin nitric acid ana bayyana su azaman kaso ta girma, yayin da sabbin abubuwan citric acid ana bayyana su azaman kaso ta taro.Yana da mahimmanci a lura cewa lokacin yin waɗannan hanyoyin, ma'auni mai mahimmanci na lokacin jiƙa, zafin wanka, da kuma maida hankali yana da mahimmanci don kauce wa "flashing" da aka bayyana a sama.
Passivation ya bambanta dangane da abun ciki na chromium da halayen sarrafawa na kowane iri-iri.Yi la'akari da ginshiƙan don ko dai Tsari 1 ko Tsari 2. Kamar yadda aka nuna a hoto na 3, Tsarin 1 yana da ƙarancin matakai fiye da Tsarin 2.
Gwaje-gwajen gwaje-gwaje sun nuna cewa tsarin wucewar citric acid ya fi dacewa da "tafasa" fiye da tsarin nitric acid.Abubuwan da ke haifar da wannan harin sun haɗa da zafin wanka mai yawa, tsayin lokacin jiƙa, da gurɓataccen wanka.Kayayyakin tushen citric acid da ke ɗauke da masu hana lalata da sauran abubuwan da ake ƙarawa kamar su jika ana samun su ta kasuwanci kuma ana ba da rahoton rage haɗarin “lalata walƙiya”.
Zaɓin ƙarshe na hanyar wucewa zai dogara ne akan sharuɗɗan karɓa wanda abokin ciniki ya saita.Duba ASTM A967 don cikakkun bayanai.Ana iya isa gare shi a www.astm.org.
Ana yin gwaje-gwaje sau da yawa don kimanta saman sassan da ke wucewa.Tambayar da za a amsa ita ce "Shin wucewa yana cire baƙin ƙarfe kyauta kuma yana inganta juriya na lalata na allo don yanke atomatik?"
Yana da mahimmanci cewa hanyar gwaji ta dace da ajin da ake tantancewa.Gwaje-gwajen da suke da tsauri ba za su wuce kayan aiki masu kyau ba, yayin da gwaje-gwajen da suka yi rauni za su wuce sassan da ba su da kyau.
PH da sauƙi-machining 400 jerin bakin karfe mafi kyawun kimantawa a cikin ɗakin da ke da ikon kiyaye zafi 100% (samfurin rigar) na awanni 24 a 95°F (35°C).Sashin giciye sau da yawa shine mafi mahimmancin farfajiya, musamman don yankan maki kyauta.Ɗayan dalili na wannan shi ne cewa sulphide an ja shi a cikin hanyar injin a fadin wannan saman.
Ya kamata a sanya wurare masu mahimmanci zuwa sama, amma a kusurwar digiri 15 zuwa 20 daga tsaye, don ba da damar asarar danshi.Abubuwan da ba su da kyau ba za su yi tsatsa ba, kodayake ƙananan tabo na iya bayyana a kai.
Austenitic bakin karfe maki kuma za a iya kimanta ta da danshi gwajin.A cikin wannan gwajin, ɗigon ruwa ya kamata ya kasance a saman samfurin, yana nuna baƙin ƙarfe kyauta ta kasancewar kowane tsatsa.
Hanyoyin wucewa don yawan amfani da bakin karfe na atomatik da na hannu a cikin maganin citric ko nitric acid suna buƙatar matakai daban-daban.A kan fig.3 da ke ƙasa yana ba da cikakkun bayanai kan zaɓin tsari.
(a) Daidaita pH tare da sodium hydroxide.(b) Duba fig.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.
Hanyar da ta fi sauri ita ce amfani da ASTM A380, Ƙa'idar Ƙaƙwalwar Tsabtace, Tsaftacewa, da Ƙarfafa Ƙarfe na Bakin Karfe, Kayan aiki, da Tsarin.Gwajin ya hada da shafa bangaren da sinadarin jan karfe sulfate/sulfuric acid, ajiye shi na tsawon mintuna 6, da kuma lura da platin jan karfe.A madadin, za'a iya nutsar da sashin a cikin bayani na mintuna 6.Idan ƙarfe ya narke, platin jan karfe yana faruwa.Wannan gwajin ba zai shafi saman sassan sarrafa abinci ba.Har ila yau, bai kamata a yi amfani da shi a kan 400 jerin martensitic karafa ko ƙananan chromium ferritic karafa kamar yadda ƙarya tabbatacce sakamako na iya faruwa.
A tarihi, an kuma yi amfani da gwajin feshin gishiri na 5% a 95°F (35°C) don kimanta samfuran da suka wuce.Wannan gwajin yana da ƙarfi sosai ga wasu cultivars kuma gabaɗaya ba a buƙata don tabbatar da ingancin wuce gona da iri.
Guji yin amfani da chloride mai yawa, wanda zai iya haifar da tashin hankali mai haɗari.Yi amfani da ruwa mai inganci kawai tare da ƙasa da sassa 50 a kowace miliyan (ppm) chloride a duk lokacin da zai yiwu.Ruwan famfo yawanci ya isa, kuma a wasu lokuta yana iya jurewa sassa ɗari da yawa a cikin miliyan chlorides.
Yana da mahimmanci don maye gurbin wanka akai-akai don kada a rasa yiwuwar wucewa, wanda zai haifar da walƙiya da lalacewa ga sassa.Dole ne a kiyaye wanka a yanayin zafi da ya dace, saboda yanayin zafi mara ƙarfi na iya haifar da lalatawar gida.
Yana da mahimmanci a bi ƙayyadadden ƙayyadaddun jadawali na canjin bayani yayin manyan ayyukan samarwa don rage yiwuwar kamuwa da cuta.An yi amfani da samfurin sarrafawa don gwada tasirin wanka.Idan an kai wa samfurin hari, lokaci yayi da za a maye gurbin wanka.
Lura cewa wasu injina suna samar da bakin karfe ne kawai;yi amfani da mai sanyaya da aka fi so don yankan bakin karfe zuwa keɓe duk sauran karafa.
Ana sarrafa sassan DO rack daban don guje wa hulɗar ƙarfe zuwa ƙarfe.Wannan yana da mahimmanci musamman don ƙirar bakin karfe kyauta, kamar yadda ake buƙatar wucewa mai sauƙi da mafita don watsa samfuran lalata sulfide da hana samuwar aljihunan acid.
Kar a ƙyale sassa na bakin karfe na carburized ko nitrided.Za a iya rage juriya na lalata sassan da aka bi da su ta wannan hanya har ta yadda za su iya lalacewa a cikin wankan wucewa.
Kada a yi amfani da kayan aikin ƙarfe na ƙarfe a yanayin bita waɗanda ba su da tsabta musamman.Ana iya guje wa guntun ƙarfe ta amfani da carbide ko kayan aikin yumbu.
Ku sani cewa lalata na iya faruwa a cikin wankan wucewa idan ba a kula da sashin da zafi sosai ba.Makin Martensitic tare da babban carbon da abun ciki na chromium dole ne a taurare don juriyar lalata.
Passivation yawanci ana aiwatar da shi bayan zafin jiki na gaba a yanayin zafi da ke kula da juriyar lalata.
Kar a manta da yawan nitric acid a cikin wankan wucewa.Yakamata a yi bincike na lokaci-lokaci ta amfani da hanya mai sauƙi titration wanda Carpenter ya ba da shawarar.Kada ku wuce fiye da bakin karfe ɗaya a lokaci guda.Wannan yana hana rudani mai tsada kuma yana hana halayen galvanic.
Game da Marubuta: Terry A. DeBold kwararre ne na Bakin Karfe Alloys R&D kuma James W. Martin ƙwararren masani ne na Metallurgy a Carpenter Technology Corp.(Karanta, Pennsylvania).
Nawa ne shi din?Nawa sarari nake bukata?Wadanne matsalolin muhalli zan fuskanta?Yaya tsayin koyo yake?Menene ainihin anodizing?Da ke ƙasa akwai amsoshin tambayoyin farko na masters game da anodizing ciki.
Samun daidaito, sakamako mai inganci daga tsarin niƙa marar tsakiya yana buƙatar fahimtar asali.Yawancin matsalolin aikace-aikacen da ke da alaƙa da niƙa marar tsakiya sun taso ne daga rashin fahimtar tushen tushe.Wannan labarin yana bayyana dalilin da yasa tsarin rashin hankali ke aiki da yadda ake amfani da shi sosai a cikin bitar ku.