Uqinisekise ukuthi izingxenye zenziwe ngomshini ngendlela ecacisiwe.Manje, qiniseka ukuthi uthathe izinyathelo zokuvikela lezi zingxenye ngaphansi kwezimo ezilindelwe amakhasimende akho.#okuyisisekelo
I-passivation isalokhu iyisinyathelo esibalulekile ekwandiseni ukumelana nokugqwala okuyisisekelo kwezingxenye zemishini engagqwali kanye nama-assemblies.Kungenza umehluko phakathi kokusebenza okwanelisayo nokwehluleka ngaphambi kwesikhathi.Ukwenziwa ngendlela engafanele, ukudlula kungabangela ukugqwala.
I-Passivation iyindlela yangemva kokwenziwa ekhulisa ukumelana nokugqwala kwemvelo kwezingxubevange zensimbi engagqwali ezikhiqiza ucezu lokusebenza.Akuwona ukwelashwa kokwehlisa, futhi akukona ukunamathela ngopende.
Akukho ukuvumelana okujwayelekile mayelana nendlela eqondile yokuthi i-passivation isebenza kanjani.Kodwa kuqinisekile ukuthi kunefilimu ye-oxide evikelayo ebusweni bensimbi engagqwali edlulayo.Le filimu engabonakali kucatshangwa ukuthi incane kakhulu, ingaphansi kwamayintshi angu-0.0000001, cishe u-1/100,000 ukujiya kwezinwele zomuntu!
Ingxenye yensimbi engagqwali ehlanzekile, esanda mshini, epholishiwe noma efakwe emanzini afakwe emanzini afakwe emanzini anosawoti izothola ngokuzenzakalelayo le filimu ye-oxide ngenxa yokuchayeka kumoya-mpilo womkhathi.Ngaphansi kwezimo ezikahle, lesi singqimba se-oxide esivikelayo sivala ngokuphelele zonke izindawo zengxenye.
Kodwa-ke, ekusebenzeni, ukungcola okufana nokungcola kwesitolo noma izinhlayiya zensimbi ezivela kumathuluzi okusika kungadlulisela ebusweni bezingxenye zensimbi engagqwali ngesikhathi somshini.Uma zingasuswa, lezi zindikimba zakwamanye amazwe zinganciphisa ukusebenza kwefilimu yokuqala yokuvikela.
Ngesikhathi somshini, ukulandelela amanani ensimbi yamahhala angaguga ithuluzi futhi adluliselwe ebusweni bomsebenzi wensimbi engagqwali.Kwezinye izimo, ingxenye encane yokugqwala ingase ivele engxenyeni.Lokhu empeleni ukugqwala kwensimbi yithuluzi, hhayi isisekelo sensimbi.Ngezinye izikhathi, imifantu yezinhlayiya zensimbi ezishunyekiwe ezivela kumathuluzi okusika noma imikhiqizo yazo yokugqwala kungabangela ukuguguleka kwengxenye ngokwayo.
Ngokufanayo, izinhlayiya ezincane zokungcola kwesitolo okusansimbi zinganamathela ebusweni bengxenye.Nakuba insimbi ingase ibonakale icwebezela esimweni somshini, ngemva kokuchayeka emoyeni, izinhlayiya ezingabonakali zensimbi yamahhala zingabangela ukugqwala kwendawo.
Ama-sulfide abonisiwe nawo angaba yinkinga.Avela ekungezeni isibabule ensimbini engagqwali ukuze kuthuthukiswe i-machinability.Ama-Sulfide akhulisa i-alloy ikhono lokwenza ama-chips ngesikhathi somshini, angasuswa ngokuphelele ethuluzini lokusika.Ngaphandle kokuthi izingxenye zidluliswe kahle, ama-sulfide angaba isiqalo sokugqwala komhlaba emikhiqizweni eyenziwe.
Kuzo zombili izimo, i-passivation iyadingeka ukuze kwandiswe ukumelana nokugqwala kwemvelo kwensimbi engagqwali.Isusa ukungcola okungaphezulu, njengezinhlayiya zokungcola kwesitolo esisansimbi kanye nezinhlayiya zensimbi kumathuluzi okusika, ezingakha ukugqwala noma zibe isiqalo sokugqwala.I-Passivation iphinde isuse ama-sulfide avele ebusweni bensimbi engagqwali esika mahhala.
Inqubo enezinyathelo ezimbili inikeza ukumelana nokugqwala okungcono kakhulu: 1. Ukuhlanza, inqubo eyisisekelo kodwa ngezinye izikhathi enganakwa;2. Ukugeza nge-Acid noma ukwelashwa kwe-passivation.
Ukuhlanza kufanele kube yinto ehamba phambili ngaso sonke isikhathi.Indawo engaphezulu kufanele ihlanzwe kahle kumafutha, into epholile noma enye imfucumfucu yasesitolo ukuze ikwazi ukumelana nokugqwala.Imfucumfucu yomshini noma okunye ukungcola kwasesitolo kungasulwa ngokucophelela engxenyeni.Izinto zokukhipha amafutha zezentengiselwano noma izinto zokuhlanza zingasetshenziswa ukususa uwoyela ocutshungulwayo noma izinto ezipholile.
Ngezinye izikhathi umqhubi womshini angase eqe ukuhlanza okuyisisekelo, ngephutha acabange ukuthi ukuhlanzwa nokunciphisa kuzokwenzeka ngesikhathi esisodwa ngokumane acwilise ingxenye egcwele amafutha endaweni yokugeza ene-asidi.Lokhu ngeke kwenzeke.Ngokuphambene nalokho, amafutha angcolile ahlangana ne-asidi enze amabhamuza omoya.Lawa mabhamuza aqoqana endaweni yokusebenza futhi aphazamise ukuphefumula.
Okwenza izinto zibe zimbi nakakhulu, ukungcoliswa kwezixazululo ze-passivation, ngezinye izikhathi eziqukethe ukugxila okuphezulu kwama-chloride, kungabangela "ukucwebezela." Ngokungafani nokuthola ifilimu ye-oxide efiselekayo enendawo ecwebezelayo, ehlanzekile, ekwazi ukumelana nokugqwala, ukukhanya kwe-flash kungaholela endaweni egcizelelwe kakhulu noma emnyama—ukuwohloka kobuso okuklanyelwe ukwenziwa ngcono.
Izingxenye ezenziwe ngensimbi engagqwali ye-martensitic [umazibuthe, imelana ngokulingene nokugqwala, ikhiqiza amandla afinyelela ku-280 ksi (1930 MPa)] iqiniswe emazingeni okushisa aphakeme bese iqinisiwe ukuze kuqinisekiswe ubulukhuni obufunwayo kanye nezakhiwo eziwumshini. , bese eqeda.
Kulesi simo, ingxenye kufanele ihlanzwe kahle nge-degreaser noma i-cleaner ukuze kususwe noma yiziphi izinsalela zokusika uketshezi ngaphambi kokwelashwa kokushisa.Ngaphandle kwalokho, uketshezi olunqunyiwe olusele engxenyeni lungabangela i-oxidation eyeqile.Lesi simo singabangela izingxenye ezingaphansi kobukhulu ukuba zibole ngemva kokuba isikali sisusiwe nge-asidi noma izindlela ezi-abrasive. ukumelana nokugqwala.
Ngemva kokuhlanza ngokuphelele, izingxenye zensimbi engagqwali zingacwiliswa ekugezeni kwe-asidi edlulayo.Noma iyiphi yezindlela ezintathu zingasetshenziswa - i-nitric acid passivation, i-nitric acid ene-sodium dichromate passivation, ne-citric acid passivation.Iyiphi indlela okufanele isetshenziswe incike ebangeni lensimbi engagqwali kanye nenqubo yokwamukela ecacisiwe.
Amamaki e-chrome-nickel angagqwali engeziwe angadluliswa kubhavu ye-nitric acid engu-20% (v/v) (Umfanekiso 1). Njengoba kubonisiwe etafuleni, insimbi engagqwali engazweli kancane ingadluliswa ngokungeza i-sodium dichromate kubhavu we-nitric acid, okwenza ikhambi libe oxidizing kakhulu futhi likwazi ukwenza indawo yokugxilisa i-nichromate yensimbi esikhundleni se-nichromate yensimbi inketho ye-nichromate yensimbi i-tric acid ukuya ku-50% ngevolumu.Kokubili ukungezwa kwe-sodium dichromate kanye nokuhlushwa okuphezulu kwe-nitric acid kunciphisa ithuba lokukhanya okungafunwa.
Inqubo yokudlula izinsimbi ezingenasici ezisebenza mahhala (futhi ekhonjiswe kuMfanekiso 1) ihluke ngandlela thize kuleyo yamabanga ensimbi engenasici. Lokhu kungenxa yokuthi phakathi nokugeza okujwayelekile kwe-nitric acid, amanye noma wonke ama-sulfide ebanga lesulfure aqukethe isibabule ayasuswa, okwenza ingxenye encane yomshini ingaqhubeki.
Ngisho nokugeza okujwayelekile kwamanzi okusebenzayo kungashiya i-asidi eyinsalela kulokhu kungaqhubeki ngemva kokudlula.Le asidi izobe isihlasela ingxenye engaphezulu ngaphandle uma ingashintshiwe noma isusiwe.
Ukuze kudlulwe ngokuphumelelayo insimbi engagqwali eshintshwa kalula, uMbazi uthuthukise inqubo ye-AAA (Alkali-Acid-Alkali), eyenza i-asidi esele ingathathi hlangothi.Le ndlela yokudlulisa ingaqedwa ngaphansi kwamahora angu-2. Nansi inqubo yesinyathelo nesinyathelo:
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. Okulandelayo, cwilisa ingxenye imizuzu engu-30 ku-20% (v/v) isixazululo se-nitric / l se-nitric / l esiqukethe ku-12 ° F ye-sodium engu-12 ° equkethe ku-12 oz 40°F (49°C) kuya ku-60°C).Ngemuva kokukhipha ingxenye ekugezeni, yihlanza ngamanzi bese uyicwilisa kwisisombululo se-sodium hydroxide eminye imizuzu engu-30. Hlanza ingxenye futhi ngamanzi futhi uyomile, ugcwalise indlela ye-AAA.
I-Citric acid passivation iya ngokuya ithandwa ngabakhiqizi abafisa ukugwema ukusetshenziswa kwe-mineral acids noma izixazululo eziqukethe i-sodium dichromate, kanye nezindaba zokulahla kanye nokukhathazeka okukhulu kokuphepha okuhambisana nokusetshenziswa kwabo.I-Citric acid ibhekwa njengobungani bemvelo ngazo zonke izindlela.
Nakuba i-citric acid passivation inikeza izinzuzo ezikhangayo zemvelo, izitolo ezibe nempumelelo nge-acid passivation ye-inorganic futhi ezingenakho ukukhathazeka ngokuphepha zingase zifune ukuqhubeka nesifundo.Uma laba basebenzisi benesitolo esihlanzekile, izinto zokusebenza ezinakekelwa kahle nezihlanzekile, into epholile engenawo ukungcola kwezitolo okusansimbi, kanye nenqubo ekhiqiza imiphumela emihle, kungase kungabi khona isidingo sangempela soshintsho.
I-passivation kubhavu ye-citric acid itholakale ilusizo kuhlu olukhulu lwezinsimbi ezingenasici, okuhlanganisa amamaki ensimbi engagqwali amaningana, njengoba kuboniswe kuMfanekiso 2.Ukuze kube lula, indlela yendabuko ye-nitric acid passivation ku-Figure 1 ifakiwe.Qaphela ukuthi ukwakheka kwe-nitric acid endala kuvezwa ngamaphesenti wevolumu, kuyilapho ukugxiliswa kwe-citric acid entsha kuboniswa, kubalulekile ukulinganisa izinga lokushisa ukuze inothi le-bancing yesikhathi, ibhalansi ye-bancing yamaphesenti. futhi ukugxilisa ingqondo kubalulekile ukuze ugweme "ukukhanya" okuchazwe ngaphambili.
Ukwelashwa kwe-passivation kuyehluka ngokuya ngokuqukethwe kwe-chromium nezici zomshini zebanga ngalinye.Qaphela amakholomu abhekisela kuNqubo 1 noma Inqubo 2.Njengoba kuboniswe kuMfanekiso 3, Inqubo 1 ihilela izinyathelo ezimbalwa kuneNqubo yesi-2.
Ukuhlolwa kwelabhorethri kubonise ukuthi inqubo ye-citric acid passivation ijwayele "ukukhanya" kunenqubo ye-nitric acid.Izici ezinomthelela kulokhu kuhlasela zihlanganisa izinga lokushisa eliphezulu kakhulu lokugeza, isikhathi eside kakhulu sokucwilisa, kanye nokungcola okugeza.Imikhiqizo ye-citric acid equkethe i-corrosion inhibitors nezinye izithasiselo ezifana nama-agent wokumanzisa ayatholakala futhi kubikwa ukuthi anciphisa i-susceptibility corrosion.
Indlela yokugcina yokukhetha izoncika kumbandela wokwamukela obekwe yikhasimende.Bona i-ASTM A967 ukuze uthole imininingwane.Ingafinyelelwa ku-www.astm.org.
Ukuhlola kuvame ukwenziwa ukuze kuhlolwe ingaphezulu lezingxenye ezingashintshiwe. Umbuzo okufanele uphendule uthi, "Ingabe i-passevation isusa i-iron yamahhala futhi ikhulise ukumelana nokugqwala kwamabanga amahhala?"
Kubalulekile ukuthi indlela yokuhlola ifane nebanga elihlolwayo.Ukuhlola okuqine kakhulu kuzofeyila izinto ezinhle kakhulu, kuyilapho ukuhlola okuxekethile kuzodlula izingxenye ezingagculisi.
400 uchungechunge lwemvula eqinisayo kanye nezinsimbi ezingenasici ezikhululekile zihlolwa kangcono ekhabetheni elikwazi ukugcina umswakama ongu-100% (isampula elimanzi) amahora angu-24 ku-95°F (35°C).Isigaba esiphambanayo sivame ukuba yindawo ebucayi kakhulu, ikakhulukazi kumamaki okusika mahhala.Isizathu esisodwa salokhu ukuthi lo mshini owenziwe nge-sulfide obude obude kumshini we-intersect.
Izindawo ezibucayi kufanele zibekwe phezulu, kodwa ku-15 kuya ku-20 degrees ukusuka mpo ukuvumela ukulahlekelwa umswakama. Izinto ezingadluliswa kahle ngeke zigle, nakuba zingase zibonise amabala amancane.
Amabanga ensimbi engagqwali ye-Austenitic nawo angahlolwa ngokuhlolwa komswakama.Uma ehlolwa kanjalo, amaconsi amanzi kufanele abe khona phezu kwesampula, abonise insimbi yamahhala ngokuba khona kwanoma yikuphi ukugqwala.
Izinqubo zokudlula izinsimbi ezingenasici ezivame ukusetshenziswa ezivame ukusika futhi ezingasikiwe ku-citric noma i-nitric acid izixazululo zidinga izinqubo ezahlukene.Umfanekiso wesi-3 ngezansi unikeza imininingwane yokukhethwa kwenqubo.
(a) Lungisa i-pH nge-sodium hydroxide.(b) Bheka Umfanekiso 3 (c) I-Na2Cr2O7 imele u-3 oz/gallon (22 g/l) sodium dichromate ku-20% nitric acid. Enye indlela yale ngxube ngu-50% nitric acid ngaphandle kwe-sodium dichromate
Indlela esheshayo ukusebenzisa isixazululo ku-ASTM A380, "Umkhuba Ojwayelekile Wokuhlanza, Ukwehlisa, Nokudlulisa Izingxenye Zensimbi Engagqwali, Izinsizakusebenza, kanye Nezinhlelo." Ukuhlolwa kuhlanganisa ukusula ingxenye ngesisombululo se-copper sulfate/sulfuric acid, ukuyigcina imanzi imizuzu eyi-6 bese ubheka ingxenye ye-ayina yokucwiliswa kwe-ayina eyi-6. iyaxazulula, i-copper plating iyenzeka.Lokhu kuhlolwa akusebenzi endaweni engaphezulu yezingxenye zokucubungula ukudla.Futhi, akufanele kusetshenziselwe izinsimbi ze-martensitic ezingu-400 noma eziphansi ze-chromium ferritic njengoba kungase kuvele imiphumela emihle engamanga.
Ngokomlando, ukuhlolwa kwesifutho sikasawoti esingu-5% ku-95°F (35°C) nakho kuye kwasetshenziswa ukuze kuhlolwe amasampula angazange aphumelele.Lokhu kuhlola kuqinile kwamanye amabanga futhi ngokuvamile akudingekile ukuze kuqinisekiswe ukuthi ukuphasa kuyasebenza.
Gwema ukusebenzisa ama-chloride amaningi, angabangela ukuhlasela kwe-flash okuyingozi.Uma kungenzeka, sebenzisa amanzi ekhwalithi ephezulu kuphela anezingxenye ezingaphansi kuka-50 esigidini (ppm) chloride.Amanzi ompompi ngokuvamile anele futhi angabekezelela i-chloride efika kumakhulu ambalwa kwezinye izimo.
Kubalulekile ukushintsha indawo yokugeza njalo ukuze ungalahlekelwa amandla okudlula, okungaholela ekushayweni kombani kanye nezingxenye ezilimele.Ukugeza kufanele kugcinwe ezingeni lokushisa elifanele, njengoba izinga lokushisa elibalekayo lingabangela ukugqwala kwendawo.
Kubalulekile ukugcina ishejuli yokushintsha isixazululo esiqondile ngesikhathi sokukhiqiza okuphezulu ukuze kuncishiswe amandla okungcola.Isampula yokulawula yasetshenziselwa ukuhlola ukusebenza kahle kokugeza.Uma isampula ihlaselwa, yisikhathi sokushintsha indawo yokugeza.
Sicela ucacise ukuthi imishini ethile yenza insimbi engagqwali kuphela;sebenzisa isipholile esifanayo esithandwayo ukusika insimbi engagqwali, ngaphandle kwazo zonke ezinye izinsimbi.
Izingxenye ze-DO rack ziphathwa ngokuhlukana ukuze kugwenywe ukuthintana kwe-metal-to-metal.Lokhu kubaluleke kakhulu emshinini wamahhala wensimbi engagqwali, njengoba i-passivation egelezayo yamahhala kanye nezixazululo zokugeza zidingeka ukuze kuhlakazwe imikhiqizo yokugqwala kwe-sulfide nokugwema ukwakheka kwamaphakethe e-asidi.
Ungadlulisi izingxenye zensimbi engagqwali e-carburized noma ene-nitrided.Ukumelana nokugqwala kwezingxenye eziphathwe ngale ndlela kungase kwehliswe kuze kufike lapho zizohlaselwa khona kubhavu wokudlula.
Ungasebenzisi amathuluzi ayoni endaweni yokusebenzela engahlanzekile ngokukhethekile.Igrit yensimbi ingagwenywa ngokusebenzisa i-carbide noma amathuluzi e-ceramic.
Ungakhohlwa ukuthi ukugqwala kungenzeka kubhavu we-passivation uma ingxenye ingaphathwa kahle ukushisa.Ikhabhoni ephezulu, amamaki e-chromium martensitic aphezulu kumele aqiniswe ukuze amelane nokugqwala.
I-passivation imvamisa yenziwa ngemuva kokufutheka okulandelayo kusetshenziswa amazinga okushisa agcina ukumelana nokugqwala.
Ungakushayi indiva ukugcwala kwe-nitric acid kubhavu we-passivation.Ukuhlolwa ngezikhathi ezithile kufanele kwenziwe kusetshenziswa inqubo elula yokuguqula i-titration ehlinzekwe ngu-Carpenter.Ungadlulisi insimbi engagqwali engaphezu kweyodwa ngesikhathi.Lokhu kuvimbela ukudideka okumba eqolo futhi kugweme ukusabela kwe-galvanic.
Mayelana nababhali: U-Terry A. DeBold uchwepheshe wokucwaninga nokuthuthukiswa kwe-alloy yensimbi engagqwali futhi u-James W. Martin uyi-bar metallurgist e-Carpenter Technology Corp. (Reading, PA).
Ezweni lezichasiselo zokuphela kwendawo eziqinile, izilinganiso ezilula “zokumahhadlahhadla” zisawusizo. Ake sibheke ukuthi kungani ukukala kwendawo kubalulekile nokuthi kungabhekwa kanjani phansi esitolo ngamageji aphathekayo ayinkimbinkimbi.
Uqinisekile ukuthi unokufaka okungcono kakhulu kwalo msebenzi wokujika?Hlola i-chip, ikakhulukazi uma ishiywe inganakiwe.Izici ze-chip zingakutshela okuningi.