Uqinisekise ukuthi izingxenye zenziwa ngendlela ebekiwe.Manje qiniseka ukuthi uthatha izinyathelo zokuvikela lezi zingxenye endaweni elindelwe ngamakhasimende akho.#isisekelo
I-passivation isalokhu iyisinyathelo esibalulekile ekwandiseni ukumelana nokugqwala kwezingxenye nezihlanganisi ezenziwe ngomshini ngensimbi engagqwali.Lokhu kungenza umehluko phakathi kokusebenza okwanelisayo nokwehluleka ngaphambi kwesikhathi.I-passivation engalungile ingabangela ukugqwala.
I-Passivation iyindlela yokwenziwa yangemva kokwenziwa ekhulisa ukumelana nokugqwala okungokwemvelo kwama-alloys ensimbi engagqwali okwenziwa ngawo ucezu lokusebenza.Lokhu akukhona ukwehliswa noma ukudweba.
Akukho ukuvumelana mayelana nendlela okuyiyona ndlela i-passivation esebenza ngayo.Kodwa kuyaziwa ngokuqinisekile ukuthi kukhona ifilimu ye-oxide evikelayo ebusweni bensimbi engagqwali edlulayo.Le filimu engabonakali kuthiwa izacile ngokwedlulele, ingaphansi kuka-0.0000001 inch ugqinsi, okungaba ugqinsi luka-1/100,000 lwezinwele zomuntu!
Ingxenye yensimbi engagqwali ehlanzekile, esanda mshini, epholishiwe, noma efakwe emanzini anosawoti izothola ngokuzenzakalelayo le filimu ye-oxide ngenxa yokuchayeka kumoya-mpilo womkhathi.Ngaphansi kwezimo ezikahle, lolu ungqimba lwe-oxide oluvikelayo luhlanganisa ngokuphelele zonke izindawo zengxenye.
Kodwa-ke, ekusebenzeni, ukungcola okufana nokungcola kwefekthri noma izinhlayiya zensimbi ezivela kumathuluzi okusika zingafika phezu kwezingxenye zensimbi engagqwali ngesikhathi sokucubungula.Uma ingakhishiwe, le mizimba yangaphandle ingase yehlise ukusebenza kwefilimu yokuvikela yasekuqaleni.
Ngesikhathi somshini, iminonjana yensimbi yamahhala ingasuswa ethuluzini futhi idluliselwe ebusweni bomsebenzi wensimbi engagqwali.Kwezinye izimo, ungqimba oluncane lokugqwala lungase luvele engxenyeni.Eqinisweni, lokhu ukugqwala kwensimbi yamathuluzi, hhayi isisekelo sensimbi.Ngezinye izikhathi imifantu evela ezinhlayiyeni zensimbi ezishumekiwe ezivela kumathuluzi okusika noma imikhiqizo yazo yokugqwala ingaguguleka ingxenye ngokwayo.
Ngokufanayo, izinhlayiya ezincane zokungcola kwe-ferrous metallurgical zinganamathela ebusweni bengxenye.Nakuba insimbi ingase ibonakale icwebezela esimweni sayo esiphelile, ngemva kokuchayeka emoyeni, izinhlayiya ezingabonakali zensimbi yamahhala zingabangela ukugqwala okungaphezulu.
Ama-sulfide adaluliwe nawo angaba yinkinga.Zenziwa ngokungeza isulfure ensimbini engagqwali ukuze kuthuthukiswe ukusebenza kahle.Ama-sulfide akhulisa amandla e-alloy ukwenza ama-chips ngesikhathi somshini, angasuswa ngokuphelele ethuluzini lokusika.Uma izingxenye zingasulwa ngendlela efanele, ama-sulfide angaba isiqalo sokugqwala kwemikhiqizo yezimboni.
Kuzo zombili izimo, i-passivation iyadingeka ukuze kwandiswe ukumelana nokugqwala kwemvelo kwensimbi engagqwali.Isusa ukungcola okungaphezulu njengezinhlayiya zensimbi nezinhlayiya zensimbi kumathuluzi okusika angenza ukugqwala noma abe indawo yokuqala ukugqwala.I-passivation iphinde isuse ama-sulfide atholakala endaweni evulekile yama-alloys ensimbi engagqwali.
Inqubo enezinyathelo ezimbili inikeza ukumelana nokugqwala okungcono kakhulu: 1. Ukuhlanza, inqubo eyinhloko, kodwa ngezinye izikhathi inganakwa 2. Ukugeza nge-Acid noma i-passivation.
Ukuhlanza kufanele kube yinto ehamba phambili ngaso sonke isikhathi.Indawo engaphezulu kufanele ihlanzwe kahle kufakwe amafutha, isipholile noma enye imfucumfucu ukuze kuqinisekiswe ukumelana nokugqwala okuphelele.Imfucumfucu yomshini noma okunye ukungcola kwasefekthri kungasulwa kahle engxenyeni.Ama-degreaser ezentengiselwano noma izinto zokuhlanza zingasetshenziswa ukususa amafutha okucubungula noma izinto zokupholisa.Izinto zangaphandle ezifana nama-thermal oxides zingadinga ukususwa ngezindlela ezinjengokugaya noma ukukha.
Ngezinye izikhathi u-opharetha womshini angase eqe ukuhlanza okuyisisekelo, ngephutha ekholelwa ukuthi ukuhlanzwa nokunciphisa kuzokwenzeka ngesikhathi esifanayo, ngokumane acwilise ingxenye enamafutha kubhavu we-asidi.Ngeke kwenzeke.Ngokuphambene, amafutha angcolile ahlangana ne-asidi akhe amabhamuza omoya.Lawa ma-bubbles aqoqana endaweni yokusebenza futhi aphazamise ukuhamba.
Okubi nakakhulu, ukungcoliswa kwezixazululo ze-passivation, ngezinye izikhathi eziqukethe ukugxila okuphezulu kwama-chloride, kungabangela "i-flash".Ngokuphambene nokukhiqiza ifilimu ye-oxide efiswayo enendawo ecwebezelayo, ehlanzekile, ekwazi ukumelana nokugqwala, ukuchotshozwa kwe-flash kungase kubangele ukushumeka okukhulu noma kube mnyama kwendawo—ukonakala endaweni okuklanyelwe ukuyithuthukisa.
Izingxenye zensimbi engagqwali ye-Martensitic [umazibuthe, ukumelana nokugqwala okusesilinganisweni, zinikeza amandla afinyelela ku-280 000 we-psi (1930 MPa)] zicinywa emazingeni okushisa aphezulu bese zithukutheliswa ukuze zinikeze ubulukhuni obufunwayo kanye nezakhiwo zemishini.Ama-alloys aqinile emvula (anamandla angcono nokumelana nokugqwala kunamabanga e-martensitic) angelashwa isixazululo, afakwe ngomshini kancane, aguge emazingeni okushisa aphansi, bese eqedwa.
Kulesi simo, ingxenye kufanele ihlanzwe kahle nge-degreaser noma isicoci ngaphambi kokwelashwa kokushisa ukuze kukhishwe noma yiziphi izinsalela zokusika uketshezi.Uma kungenjalo, ukupholisa okusele engxenyeni kungase kubangele i-oxidation eyeqile.Lesi simo singabangela amazinyo akhe ezingxenyeni ezincane ngemva kokwehla nge-asidi noma izindlela zokuhubhuka.Uma isipholile sishiywa ezingxenyeni eziqinile ezicwebezelayo, njengasesithandweni sevacuum noma endaweni eyisivikelo, ukubola kwengaphezulu kungenzeka, okuholela ekulahlekelweni kokungagqwali.
Ngemva kokuhlanza ngokuphelele, izingxenye zensimbi engagqwali zingacwiliswa kubhavu we-asidi edlulayo.Noma iyiphi kulezi zindlela ezintathu ingasetshenziswa - i-passivation nge-nitric acid, i-passivation ne-nitric acid ne-sodium dichromate, kanye ne-passivation nge-citric acid.Iyiphi indlela okufanele isetshenziswe incike ebangeni lensimbi engagqwali kanye nenqubo yokwamukela ecacisiwe.
Amabanga e-chromium e-nickel amaningi amelana nokugqwala angadluliswa kubhavu we-nitric acid engu-20% (v/v) (Umfanekiso 1).Njengoba kubonisiwe kuthebula, izinsimbi ezingenasici ezingamelana kancane zingadluliswa ngokungeza i-sodium dichromate kubhavu ye-nitric acid ukuze kwenziwe isisombululo sibe ne-oxidizing futhi sikwazi ukwenza ifilimu edlulayo endaweni yensimbi.Enye inketho yokushintsha i-nitric acid nge-sodium chromate ukukhulisa ukugcwala kwe-nitric acid kuye ku-50% ngevolumu.Kokubili ukungezwa kwe-sodium dichromate kanye nokugcwala okuphezulu kwe-nitric acid kunciphisa amathuba okuba ne-flash engadingeki.
Inqubo ye-passivation yezinsimbi ezingenasici ezikwazi umshini (ephinde ikhonjiswe ku-Fig. 1) ihluke kancane enkambweni yamamaki ensimbi engenasici.Lokhu kungenxa yokuthi ngesikhathi sokudlula kubhavu ye-nitric acid amanye noma wonke ama-sulfide aqukethe isulfure asuswayo, okwenza ama-inhomogeneities amancane ebusweni bomsebenzi.
Ngisho nokugeza amanzi okujwayelekile okusebenzayo kungashiya i-asidi eyinsalela kulokhu kunqanyulwa ngemva kokudlula.Le asidi izohlasela ingaphezulu lengxenye uma ingashintshiwe noma ingasuswa.
Ukuze kusebenze kahle insimbi engagqwali etholakala kalula emshinini, uMbazi uthuthukise inqubo ye-AAA (Alkaline-Acid-Alkaline), eyenza i-asidi esele ingabi namandla.Le ndlela yokudlulisa ingaqedwa ngaphansi kwamahora ama-2.Nansi inqubo yesinyathelo ngesinyathelo:
Ngemuva kokunciphisa, cwilisa izingxenye ku-5% yesisombululo se-sodium hydroxide ku-160 ° F kuya ku-180 ° F (71 ° C kuya ku-82 ° C) imizuzu engu-30.Bese uhlanza izingxenye kahle emanzini.Bese ucwilisa ingxenye imizuzu engu-30 kusisombululo se-nitric acid esingu-20% (v/v) esiqukethe u-3 oz/gal (22 g/l) sodium dichromate ku-120°F kuya ku-140°F (49°C) kuya ku-60°C.) Ngemva kokukhipha ingxenye ekugezeni, yihlanza ngamanzi, bese uyicwilisa ngesisombululo se-sodium hydroxide imizuzu engu-30.Hlanza ingxenye futhi ngamanzi futhi uyomise, ugcwalise indlela ye-AAA.
I-citric acid passivation iya ngokuya ithandwa ngabakhiqizi abafuna ukugwema ukusetshenziswa kwamaminerali acids noma izixazululo eziqukethe i-sodium dichromate, kanye nezinkinga zokulahla kanye nokukhathazeka okwandayo kokuphepha okuhlobene nokusetshenziswa kwabo.I-Citric acid ithathwa njengenobungani bemvelo kuzo zonke izici.
Nakuba i-citric acid passivation inikeza izinzuzo ezikhangayo zemvelo, izitolo ezibe nempumelelo nge-inorganic acid passivation futhi ezingenakho ukukhathazeka ngokuphepha zingase zifune ukuqhubeka nesifundo.Uma laba basebenzisi benesitolo esihlanzekile, okokusebenza kusesimweni esihle futhi kuhlanzekile, okokupholisa akunawo amadiphozithi ayoni asembonini, futhi inqubo ikhiqiza imiphumela emihle, kungase kungabi khona isidingo sangempela soshintsho.
I-Citric acid bath passivation itholakale iwusizo ezinhlobonhlobo zezinsimbi ezingenasici, kufaka phakathi amamaki amaningana ensimbi engagqwali, njengoba kuboniswe kuMfanekiso 2. Ukuze kube lula, Umfanekiso 2. 1 uhlanganisa indlela yendabuko yokudlula nge-nitric acid.Qaphela ukuthi ukwakheka kwe-nitric acid endala kuvezwa njengamaphesenti ngevolumu, kuyilapho ukugxiliswa kwe-citric acid entsha kuvezwa njengamaphesenti ngesisindo.Kubalulekile ukuqaphela ukuthi lapho wenza lezi zinqubo, ibhalansi ngokucophelela yesikhathi sokucwilisa, izinga lokushisa lokugeza, nokugxila kubalulekile ukugwema "ukukhanya" okuchazwe ngenhla.
I-passivation iyahlukahluka kuye ngokuqukethwe kwe-chromium nezici zokucubungula zenhlobo ngayinye.Qaphela amakholomu eNqubo 1 noma Inqubo 2. Njengoba kuboniswe kuMfanekiso 3, Inqubo 1 inezinyathelo ezimbalwa kuneNqubo yesi-2.
Ukuhlolwa kwaselabhorethri kubonise ukuthi inqubo ye-citric acid passivation ijwayele "ukubilisa" kunenqubo ye-nitric acid.Izinto ezinomthelela kulokhu kuhlasela zihlanganisa izinga lokushisa eliphezulu kakhulu lokugeza, isikhathi sokucwilisa eside kakhulu, nokungcoliswa kokugeza.Imikhiqizo esekelwe ku-citric acid equkethe i-corrosion inhibitors nezinye izithasiselo ezifana nama-ejenti wokumanzisa ayatholakala ngokwentengiso futhi kubikwa ukuthi yehlisa ukuthambekela “kokugqwala kwe-flash”.
Inketho yokugcina yendlela yokudlulisa izoncika kunqubo yokwamukela ebekwe yikhasimende.Bona i-ASTM A967 ngemininingwane.Ingatholakala ku-www.astm.org.
Ukuhlolwa kuvame ukwenziwa ukuze kuhlolwe ingaphezulu lezingxenye ezidlule.Umbuzo okufanele uphendulwe uthi "Ingabe i-passivation isusa i-iron yamahhala futhi ikhulise ukumelana nokugqwala kwama-alloys ekusikeni okuzenzakalelayo?"
Kubalulekile ukuthi indlela yokuhlola ihambisane nekilasi elihlolwayo.Ukuhlolwa okuqine kakhulu ngeke kudlule izinto ezinhle ngokuphelele, kuyilapho izivivinyo ezibuthakathaka kakhulu zizodlula izingxenye ezingagculisi.
I-PH kanye nochungechunge olulula lwezinsimbi ezingama-400 ezisebenza kalula zihlolwa kangcono ekamelweni elikwazi ukugcina umswakama ongu-100% (isampula limanzi) amahora angu-24 ku-95°F (35°C).Isigaba esiphambene ngokuvamile siyindawo ebaluleke kakhulu, ikakhulukazi amamaki okusika mahhala.Esinye isizathu salokhu ukuthi i-sulfide idonselwa ohlangothini lomshini ngaphesheya kwendawo.
Izindawo ezibucayi kufanele zibekwe phezulu, kodwa nge-engeli engu-15 kuya ku-20 degrees ukusuka mpo, ukuvumela ukulahleka komswakama.Izinto ezingene ngendlela efanele ngeke zigle, nakuba kungase kuvele amachashaza amancane kuyo.
Amabanga ensimbi engagqwali ye-Austenitic nawo angahlolwa ngokuhlolwa komswakama.Kulesi sivivinyo, amaconsi amanzi kufanele abe khona ebusweni besampula, ekhombisa insimbi yamahhala ngokuba khona kwanoma yikuphi ukugqwala.
Izinqubo ze-passivation zezinsimbi ezingenasici ezizenzakalelayo nezisetshenziswa ngesandla ku-citric noma i-nitric acid izixazululo zidinga izinqubo ezahlukene.Emkhiwaneni.3 ngezansi inikeza imininingwane ngokukhetha inqubo.
(a) Lungisa i-pH nge-sodium hydroxide.(b) Bheka umkhiwane.I-3(c) I-Na2Cr2O7 ingu-3 oz/gal (22 g/L) i-sodium dichromate ku-20% nitric acid.Enye indlela yale ngxube i-50% ye-nitric acid ngaphandle kwe-sodium dichromate.
Indlela esheshayo ukusebenzisa i-ASTM A380, Ukuzijwayeza Okujwayelekile Kokuhlanza, Ukwehlisa, kanye Nokudlulisa Izingxenye Zensimbi Engagqwali, Izisetshenziswa, kanye Nezinhlelo.Ukuhlolwa kuhlanganisa ukusula ingxenye ngesisombululo se-copper sulfate/sulfuric acid, ukuyigcina imanzi imizuzu engu-6, nokubheka ukucwecwa kwethusi.Ngaphandle kwalokho, ingxenye ingacwiliswa kwisisombululo imizuzu engu-6.Uma insimbi incibilika, i-copper plating iyenzeka.Lokhu kuhlola akusebenzi endaweni engaphezulu yezingxenye zokucubungula ukudla.Futhi, akufanele isetshenziswe ku-400 series martensitic steels noma izinsimbi ze-chromium ferritic eziphansi njengoba kungase kube nemiphumela emihle engamanga.
Ngokomlando, ukuhlolwa kwesifutho sikasawoti esingu-5% ku-95°F (35°C) nakho kuye kwasetshenziswa ukuze kuhlolwe amasampula angenziwanga.Lokhu kuhlola kuqine kakhulu kwamanye ama-cultivar futhi ngokuvamile akudingekile ukuze kuqinisekiswe ukusebenza kahle kwe-passivation.
Gwema ukusebenzisa ama-chloride amaningi, okungadala ukuqubuka okuyingozi.Sebenzisa amanzi ekhwalithi ephezulu kuphela anezingxenye ezingaphansi kuka-50 ngesigidi (ppm) chloride noma nini lapho kunokwenzeka.Amanzi kampompi ngokuvamile anele, futhi kwezinye izimo angakwazi ukumelana nezingxenye ezifika emakhulwini ambalwa esigidini sama-chloride.
Kubalulekile ukufaka esikhundleni sokugeza njalo ukuze ungalahlekelwa amandla okudlula, okungaholela ekushayweni kombani kanye nokulimala kwezingxenye.Ukugeza kufanele kugcinwe ezingeni lokushisa elifanele, njengoba amazinga okushisa angalawuleki angabangela ukugqwala kwendawo.
Kubalulekile ukulandela uhlelo olucacile kakhulu lokushintsha isisombululo ngesikhathi sokukhiqiza okukhulu ukuze kuncishiswe amathuba okungcola.Isampula yokulawula isetshenziswe ukuhlola ukusebenza kokugeza.Uma isifanekiso sihlaselwe, sekuyisikhathi sokushintsha indawo yokugeza.
Sicela uqaphele ukuthi eminye imishini ikhiqiza kuphela insimbi engagqwali;sebenzisa isipholile esifanayo esithandwayo ukusika insimbi engagqwali ngaphandle kwazo zonke ezinye izinsimbi.
Izingxenye zokubeka i-DO zenziwe ngomshini ngokuhlukana ukugwema ukuthintana kwensimbi nensimbi.Lokhu kubaluleke kakhulu ekusetshenzisweni kwamahhala kwensimbi engagqwali, njengoba kudingeka izixazululo ezigeleza kalula nezisusa amanzi ukuze kusabalalise imikhiqizo yokugqwala kwe-sulfide nokuvimbela ukwakheka kwamaphakethe e-asidi.
Ungadlulisi izingxenye zensimbi engagqwali e-carburized noma ene-nitrided.Ukumelana nokugqwala kwezingxenye eziphathwa ngale ndlela kungancishiswa kuze kube yilapho zingalimala ekugezeni kwe-passivation.
Ungasebenzisi amathuluzi ensimbi ayoniwe ezimweni zokusebenzela ezingahlanzekile.Ama-chips ensimbi angagwenywa ngokusebenzisa i-carbide noma amathuluzi e-ceramic.
Qaphela ukuthi ukugqwala kungenzeka kubhavu we-passivation uma ingxenye ingaphathwanga kahle ngokushisa.Amamaki e-Martensitic anekhabhoni ephezulu kanye nokuqukethwe kwe-chromium kufanele enziwe lukhuni ukuze kumelana nokugqwala.
I-passivation ivamise ukwenziwa ngemva kokushisa okulandelayo emazingeni okushisa agcina ukumelana nokugqwala.
Ungakunaki ukugcwala kwe-nitric acid kubhavu wokudlula.Ukuhlolwa ngezikhathi ezithile kufanele kwenziwe kusetshenziswa inqubo elula yokubhala amagama ephakanyiswe uMbazi.Ungasebenzisi insimbi engagqwali engaphezu kweyodwa ngesikhathi.Lokhu kuvimbela ukudideka okubizayo futhi kuvimbela ukusabela kwe-galvanic.
Mayelana Nababhali: UTerry A. DeBold uyi-Stainless Steel Alloys R&D Specialist kanti uJames W. Martin uyi-Bar Metallurgy Specialist eCarpenter Technology Corp.(Ukufunda, ePennsylvania).
Malini lokhu?Ngidinga isikhala esingakanani?Yiziphi izinkinga zemvelo engizobhekana nazo?Ngabe ijika kangakanani ijika lokufunda?Iyini ngempela i-anodizing?Ngezansi izimpendulo zemibuzo yokuqala yamakhosi mayelana ne-anodizing ingaphakathi.
Ukuthola imiphumela engaguquki, yekhwalithi ephezulu evela kunqubo yokugaya engenaziko kudinga ukuqonda okuyisisekelo.Iningi lezinkinga zohlelo lokusebenza ezihambisana nokugaya okungenasikhungo zivela ngenxa yokungaqondi kahle izinto eziyisisekelo.Lesi sihloko sichaza ukuthi kungani inqubo engenangqondo isebenza nokuthi ungayisebenzisa kanjani ngempumelelo enkulumweni yakho yokusebenzela.