Uqinisekisile ukuba ezi nxalenye zenziwe ngokweemfuno zakho. Ngoku qiniseka ukuba uthatha amanyathelo okukhusela ezi nxalenye kwindawo elindelekileyo kubathengi bakho. #base
Ukudlulisa amandla kuseyinyathelo elibalulekileyo ekuphuculeni ukumelana nokugqwala kweenxalenye kunye neendibano ezenziwe ngentsimbi engagqwali. Oku kunokwenza umahluko phakathi kokusebenza okwanelisayo kunye nokusilela kwangaphambi kwexesha. Ukudlulisa amandla ngendlela engalunganga kunokubangela ukugqwala.
Ukudlulisa umbane yindlela yokwenza izinto emva kokwenziwa ephucula ukumelana nokugqwala kwee-alloys zentsimbi engagqwaliyo apho umsebenzi wenziwe khona. Oku akukokususa umbane okanye ukupeyinta.
Akukho sivumelwano malunga nendlela esebenza ngayo i-passivation. Kodwa kuyaziwa ngokuqinisekileyo ukuba kukho ifilimu ye-oxide ekhuselayo kumphezulu wentsimbi engagqwaliyo engasebenziyo. Le filimu ingabonakaliyo kuthiwa incinci kakhulu, ingaphantsi kwe-0.0000000 intshi enye ubukhulu, obumalunga ne-1/100,000th ubukhulu beenwele zomntu!
Inxalenye yentsimbi engenasici ecocekileyo, esandul’ ukwenziwa ngomatshini, epholishiweyo, okanye efakwe i-pickled iya kufumana le filimu ye-oxide ngokuzenzekelayo ngenxa yokuvezwa yioksijini yomoya. Phantsi kweemeko ezifanelekileyo, le layer ye-oxide ekhuselayo igubungela ngokupheleleyo yonke indawo yenxalenye.
Nangona kunjalo, ngokwesiqhelo, izinto ezingcolisayo ezifana nothuli lwasefektri okanye amasuntswana esinyithi avela kwizixhobo zokusika zinokungena kumphezulu weendawo zentsimbi engagqwaliyo ngexesha lokucubungula. Ukuba azisuswanga, ezi zinto zangaphandle zinokunciphisa ukusebenza kwefilimu yokukhusela yokuqala.
Ngexesha lokwenziwa kwesinyithi, imikhondo yesinyithi esikhululekileyo ingasuswa kwisixhobo ize idluliselwe kumphezulu wesixhobo esingenasici. Kwezinye iimeko, umaleko omncinci womhlwa unokubonakala kwinxalenye. Enyanisweni, oku kukubola kwentsimbi yesixhobo, kungekhona isinyithi esisisiseko. Ngamanye amaxesha imifantu evela kumasuntswana entsimbi afakwe kwizixhobo zokusika okanye iimveliso zazo zokubola inokuyonakalisa inxalenye ngokwayo.
Ngokufanayo, amasuntswana amancinci othuli oluvela kwisinyithi anokunamathela kumphezulu wenxalenye. Nangona isinyithi sinokubonakala sikhazimla kwimeko yaso yokugqibela, emva kokuvezwa emoyeni, amasuntswana angabonakaliyo esinyithi esikhululekileyo anokubangela umhlwa kumphezulu.
Iisulfide eziveziweyo nazo zinokuba yingxaki. Zenziwa ngokongeza isalfure kwintsimbi engatyiwayo ukuphucula ukusebenza kwayo. Iisulfide zonyusa amandla e-alloy okwenza iitships ngexesha lokwenziwa kwe-machining, ezinokususwa ngokupheleleyo kwisixhobo sokusika. Ukuba iindawo azisuswanga kakuhle, iisulfide zinokuba yindawo yokuqala yokugqwala komphezulu weemveliso zoshishino.
Kuzo zombini iimeko, i-passivation iyadingeka ukuze kuphuculwe ukumelana nokugqwala kwendalo kwentsimbi engagqwali. Isusa izinto ezingcolisayo kumphezulu ezifana namasuntswana esinyithi kunye namasuntswana esinyithi kwizixhobo zokusika ezinokwenza umhlwa okanye zibe yindawo yokuqala yokugqwala. I-passivation ikwasusa ii-sulphides ezifumaneka kumphezulu wee-alloys zentsimbi engagqwali ezivulekileyo.
Inkqubo enamanyathelo amabini inika ukhuselo olungcono kakhulu lokugqwala: 1. Ukucoca, inkqubo ephambili, kodwa ngamanye amaxesha ayihoywa 2. Ukuhlamba nge-asidi okanye ukungasebenzi.
Ukucoca kufuneka kube yeyona nto iphambili ngalo lonke ixesha. Iindawo kufuneka zicocwe kakuhle ngegrisi, i-coolant okanye ezinye izinto ezimdaka ukuqinisekisa ukumelana nokugqwala. Izinto ezimdaka zomatshini okanye ezinye izinto ezimdaka zasefektri zingasuswa kancinci kwindawo leyo. Izinto zokucoca okanye izixhobo zorhwebo zingasetyenziselwa ukususa ii-oyile okanye izinto ezimdaka. Izinto zangaphandle ezifana ne-thermal oxides zinokufuna ukususwa ngeendlela ezifana nokugaya okanye ukuqhola.
Ngamanye amaxesha umqhubi womatshini unokungawucoci umatshini ngokuphosakeleyo, ekholelwa ngempazamo ukuba ukucoca kunye nokuthambisa kuya kwenzeka ngaxeshanye, ngokufaka nje inxalenye enamafutha kwindawo yokuhlamba eneasidi. Akuyi kwenzeka. Ngokwahlukileyo koko, igrisi engcolisiweyo isabela kwiasidi ukuze yenze amaqamza omoya. La maqamza aqokelelana kumphezulu wezinto zokusebenza aze aphazamise ukuthambisa.
Okubi nangakumbi, ukungcoliswa kwezisombululo zokungangenisi manzi, ngamanye amaxesha eziqulathe ubuninzi bee-chloride, kunokubangela "i-flash". Ngokungafaniyo nokuvelisa ifilimu ye-oxide efunekayo enomphezulu okhazimlayo, ococekileyo, nongangenisi umhlwa, ukungcoliswa kwe-flash kunokubangela ukungcoliswa okukhulu okanye ukuba mnyama komphezulu—ukuwohloka komphezulu okwenza ukuba ukungcoliswa kwe-manzi kulungiselelwe ukwenza ngcono.
Izixhobo zentsimbi engenasici zeMartensitic [ezinobunewunewu, ezimelana nokugqwala okuphakathi, ezinika amandla afikelela kwi-280 lamawaka e-psi (1930 MPa)] ziyacinywa kubushushu obuphezulu zize emva koko ziqiniswe ukuze zibonelele ngobunzima obufunekayo kunye neempawu zoomatshini. Ii-alloys eziqinisiweyo zemvula (ezinamandla angcono kunye nokumelana nokugqwala kunee-martensitic grades) zinokunyangwa ngesisombululo, zifakwe ngomatshini kancinci, zigcinwe kubushushu obuphantsi, zize zigqitywe.
Kwimeko enjalo, inxalenye kufuneka icocwe kakuhle ngesixhobo sokususa amafutha okanye isicoci ngaphambi kokuba kusetyenziswe ubushushu ukuze kususwe naziphi na iintsalela zolwelo olusikiweyo. Ngaphandle koko, isicoci esisele kwinxalenye sinokubangela i-oxidation egqithisileyo. Le meko inokubangela ukuba kubekho ukuxinana kwiindawo ezincinci emva kokususwa kwee-asidi okanye iindlela zokurhawuzelela. Ukuba isicoci sishiywe kwiindawo ezikhazimlayo eziqinileyo, njengakwisithando somoya okanye kwindawo ekhuselayo, i-carburization yomphezulu inokwenzeka, nto leyo ekhokelela ekulahlekelweni kokumelana nokugqwala.
Emva kokucoca ngokucokisekileyo, iindawo zentsimbi engagqwaliyo zingafakwa kwisitya sokuhlambela esine-asidi engasebenziyo. Nayiphi na kwezi ndlela zintathu ingasetyenziswa - ukudlulisa i-asidi ye-nitric, ukudlulisa i-asidi ye-nitric ene-sodium dichromate, kunye nokudlulisa i-asidi ye-citric. Yeyiphi indlela yokusebenzisa ixhomekeke kudidi lwentsimbi engagqwaliyo kunye neendlela zokwamkelwa ezichaziweyo.
Iiklasi ze-nickel chromium ezinganyangekiyo nokugqwala zinokungangeniswa kwi-20% (v/v) nitric acid bath (Umfanekiso 1). Njengoko kubonisiwe kwitheyibhile, iintsimbi ezingatshiyo ezinganyangekiyo zingangeniswa ngokongeza i-sodium dichromate kwi-nitric acid bath ukwenza isisombululo sibe ne-oxidizing ngakumbi kwaye sikwazi ukwenza ifilimu ephazamisayo kumphezulu wesinyithi. Olunye ukhetho lokutshintsha i-nitric acid nge-sodium chromate kukunyusa uxinzelelo lwe-nitric acid ukuya kwi-50% ngomthamo. Kokubini ukongezwa kwe-sodium dichromate kunye noxinzelelo oluphezulu lwe-nitric acid kunciphisa amathuba okuba kubekho i-flash engafunekiyo.
Inkqubo yokudlulisa amandla kwiintsimbi ezingenasici ezisebenza ngomatshini (ikwaboniswe kwiFig. 1) yahluke kancinci kwinkqubo yeeklasi zentsimbi engenasici ezingasebenzi ngomatshini. Oku kungenxa yokuba ngexesha lokudlulisa amandla kwindawo yokuhlambela i-nitric acid ezinye okanye zonke ii-sulfide ezisebenza ngomatshini ezine-sulfur ziyasuswa, nto leyo eyenza ukungalingani okuncinci kumphezulu wesixhobo somsebenzi.
Nokuba ukuhlamba ngamanzi okusebenzayo ngokuqhelekileyo kunokushiya i-asidi eseleyo kwezi ndawo zingaqhubekiyo emva kokungasebenzi. Le asidi iya kuhlasela umphezulu wenxalenye ukuba ayisuswanga okanye ayisuswanga.
Ukuze intsimbi engagqwaliyo ekulula ukuyisebenzisa ngomatshini ikwazi ukuyithulula ngempumelelo, uCarpenter uphuhlise inkqubo ye-AAA (Alkaline-Acid-Alkaline), ethintela i-asidi eseleyo. Le ndlela yothulula ingagqitywa ngaphantsi kweeyure ezi-2. Nantsi inkqubo yenyathelo ngenyathelo:
Emva kokususa amafutha, faka iindawo kwisisombululo se-5% ye-sodium hydroxide kwi-160°F ukuya kwi-180°F (71°C ukuya kwi-82°C) imizuzu engama-30. Emva koko hlambulula iindawo kakuhle emanzini. Emva koko faka indawo imizuzu engama-30 kwisisombululo se-20% (v/v) se-nitric acid esine-3 oz/gal (22 g/l) ye-sodium dichromate kwi-120°F ukuya kwi-140°F (49°C) ukuya kwi-60°C. ) Emva kokususa indawo ebhafini, yihlambe ngamanzi, uze uyihlambe kwisisombululo se-sodium hydroxide imizuzu engama-30. Hlamba indawo kwakhona ngamanzi uze uyomise, ugqibezele indlela ye-AAA.
Ukususwa kwe-asidi ye-citric kuya kuthandwa kakhulu ngabavelisi abafuna ukuphepha ukusetyenziswa kwee-asidi zeminerali okanye izisombululo ezine-sodium dichromate, kunye neengxaki zokulahla kunye nokwanda kwenkxalabo yokhuseleko enxulumene nokusetyenziswa kwazo. I-asidi ye-citric ithathwa njengenobuhlobo nokusingqongileyo kuzo zonke iinkalo.
Nangona ukukhutshwa kwe-citric acid kuzisa iingenelo ezikhangayo kwindalo esingqongileyo, iivenkile eziye zaphumelela ekukhutshweni kwe-inorganic acid kwaye ezingenazo iingxaki zokhuseleko zisenokufuna ukuhlala zisebenza. Ukuba aba basebenzisi banevenkile ecocekileyo, izixhobo zikwimeko entle kwaye zicocekile, i-coolant ayinazo iidipozithi ze-ferrous zasefektri, kwaye inkqubo ivelisa iziphumo ezilungileyo, kusenokubakho mfuneko yokwenyani yokutshintsha.
Ukufakelwa kwe-asidi ye-citric bath kufunyenwe kuluncedo kwiintlobo ngeentlobo zeentsimbi ezingenasici, kuquka neendidi ezahlukeneyo zentsimbi engenasici, njengoko kubonisiwe kuMfanekiso 2. Ukuze kube lula, uMfanekiso 2. 1 ubandakanya indlela yendabuko yokufakelwa i-asidi ye-nitric. Qaphela ukuba iifomyula ze-asidi ye-nitric ezindala zibonakaliswa njengeepesenti ngobuninzi, ngelixa uxinano olutsha lwe-asidi ye-citric lubonakaliswa njengeepesenti ngobunzima. Kubalulekile ukuqaphela ukuba xa kusenziwa ezi nkqubo, ulungelelwaniso olucokisekileyo lwexesha lokuntywila, ubushushu bokuhlamba, kunye noxinano kubalulekile ukuze kuthintelwe "ukukhanya" okuchazwe apha ngasentla.
I-passivation iyahluka ngokuxhomekeke kumxholo we-chromium kunye neempawu zokucubungula zohlobo ngalunye. Qaphela iikholamu zeNkqubo 1 okanye yeNkqubo 2. Njengoko kubonisiwe kuMfanekiso 3, Inkqubo 1 inamanyathelo ambalwa kuneNkqubo 2.
Uvavanyo lwelebhu lubonise ukuba inkqubo yokudlulisa i-citric acid ithambekele kakhulu "ekubileni" kunenkqubo ye-nitric acid. Izinto ezinegalelo kolu hlaselo ziquka ubushushu obuphezulu kakhulu bokuhlamba, ixesha elide lokuntywila, kunye nongcoliseko lokuhlamba. Iimveliso ezisekelwe kwi-citric acid eziqulethe izithinteli zokugqwala kunye nezinye izongezo ezifana nee-wetting agents ziyafumaneka kurhwebo kwaye zixelwa ukuba zinciphisa umngcipheko "wokugqwala kwe-flash".
Ukhetho lokugqibela lwendlela yokudlulisa umyalezo luxhomekeke kwiikhrayitheriya zokwamkelwa ezimiselwe ngumthengi. Jonga i-ASTM A967 ukuze ufumane iinkcukacha. Ingafumaneka ku-www.astm.org.
Uvavanyo ludla ngokwenziwa ukuze kuvavanywe umphezulu weendawo ezingasebenziyo. Umbuzo oza kuphendulwa ngulo, “Ngaba ukungasebenzisi sixhobo kususa isinyithi esikhululekileyo kwaye kwenze ngcono ukumelana nokugqwala kwee-alloys ukuze zisikwe ngokuzenzekelayo?”
Kubalulekile ukuba indlela yovavanyo ihambelane neklasi evavanywayo. Uvavanyo olungqongqo kakhulu aluyi kupasa izixhobo ezilungileyo ngokupheleleyo, ngelixa uvavanyo olubuthathaka kakhulu luya kupasa iindawo ezinganelisiyo.
I-PH kunye neentsimbi ezingenasici ezingama-400 ezisebenza lula zivavanywa kakuhle kwigumbi elikwaziyo ukugcina umswakama oyi-100% (isampulu imanzi) iiyure ezingama-24 kwi-95°F (35°C). Icandelo elinqamlezileyo lidla ngokuba ngumphezulu obaluleke kakhulu, ingakumbi kwiinqanaba zokusika ezikhululekileyo. Esinye isizathu soku kukuba i-sulphide itsalwa kwicala lomatshini kulo mphezulu.
Iindawo ezibalulekileyo kufuneka zibekwe phezulu, kodwa kwi-engile ye-15 ukuya kwi-20 degrees ukusuka phezulu, ukuvumela ukulahleka komswakama. Izinto ezifakwe kakuhle aziyi kugqwala, nangona amabala amancinci angabonakala kuyo.
Iiklasi zentsimbi engagqwaliyo yase-Austenitic nazo zinokuvavanywa ngovavanyo lokufuma. Kolu vavanyo, amathontsi amanzi kufuneka abe khona kumphezulu wesampuli, nto leyo ebonisa ukuba akukho ntsimbi ikhululekileyo ngokubakho komhlwa.
Iinkqubo zokudlulisa amandla kwiintsimbi ezizenzekelayo nezingenasici ezisetyenziswa rhoqo kwizisombululo ze-citric okanye ze-nitric acid zifuna iinkqubo ezahlukeneyo. Kumfanekiso 3 ngezantsi kunika iinkcukacha malunga nokukhetha inkqubo.
(a) Lungisa i-pH nge-sodium hydroxide. (b) Jonga umfanekiso 3(c) I-Na2Cr2O7 yi-3 oz/gal (22 g/L) sodium dichromate kwi-20% nitric acid. Enye indlela yokuxuba le ngxube yi-50% nitric acid ngaphandle kwe-sodium dichromate.
Indlela ekhawulezayo kukusebenzisa i-ASTM A380, i-Standard Practice for Cleaning, Descaling, and Passivation of Stainless Steel Parts, Equipment, and Systems. Olu vavanyo luquka ukusula inxalenye ngesisombululo se-copper sulfate/sulfuric acid, ukuyigcina imanzi imizuzu emi-6, kunye nokujonga i-copper plating. Okanye, inxalenye ingantywiliselwa kwisisombululo imizuzu emi-6. Ukuba isinyithi siyanyibilika, i-copper plating iyakwenzeka. Olu vavanyo alusebenzi kumphezulu weendawo zokucubungula ukutya. Kwakhona, akufuneki isetyenziswe kwiintsimbi ze-martensitic ezingama-400 okanye kwiintsimbi ze-ferritic eziphantsi kwe-chromium njengoko iziphumo ezingalunganga zinokwenzeka.
Ngokwembali, uvavanyo lokutshiza ngetyuwa oluyi-5% kumaqondo obushushu angama-95°F (35°C) lukwasetyenziswa ukuvavanya iisampulu ezingasetyenziswanga. Olu vavanyo lunzima kakhulu kwezinye iintlobo zezityalo kwaye ngokubanzi akufuneki ukuqinisekisa ukusebenza kakuhle kokungasetyenziswanga.
Kuphephe ukusebenzisa ii-chloride ezigqithisileyo, ezinokubangela ukuqhambuka okuyingozi. Sebenzisa amanzi asemgangathweni ophezulu kuphela aneenxalenye ezingaphantsi kwama-50 kwisigidi (ppm) se-chloride nanini na xa kunokwenzeka. Amanzi empompini adla ngokwanela, kwaye kwezinye iimeko anokumelana neenxalenye ezingamakhulu kwisigidi se-chloride.
Kubalulekile ukutshintsha igumbi lokuhlambela rhoqo ukuze ungalahlekelwa ngamandla okutshayela, nto leyo enokubangela umbane kunye nomonakalo kwiindawo ezithile. Igumbi lokuhlambela kufuneka ligcinwe kubushushu obufanelekileyo, njengoko amaqondo obushushu angalawulekiyo anokubangela ukugqwala kwendawo.
Kubalulekile ukulandela ishedyuli ethile yokutshintsha isisombululo ngexesha lemveliso enkulu ukunciphisa amathuba okungcola. Isampulu yokulawula isetyenzisiwe ukuvavanya ukusebenza kakuhle kwebhafu. Ukuba isampulu ihlaselwe, lixesha lokutshintsha ibhafu.
Nceda uqaphele ukuba ezinye iimatshini zivelisa intsimbi engagqwaliyo kuphela; sebenzisa i-coolant efanayo ekhethwayo ukusika intsimbi engagqwaliyo ngaphandle kwezinye iintsimbi.
Iindawo ze-DO rack zenziwe ngomatshini ngokwahlukeneyo ukuze kuthintelwe ukudibana kwentsimbi nesinyithi. Oku kubaluleke kakhulu ekusetyenzisweni kwentsimbi engagqwaliyo simahla, njengoko izisombululo zokuthambisa kunye nokuhlanjwa okulula ziyafuneka ukuze kusasazwe iimveliso zokugqwala kwe-sulfide kwaye kuthintelwe ukwakheka kweepokotho ze-asidi.
Musa ukukhupha izinto zentsimbi engagqwaliyo ezifakwe ikhabhoni okanye ezifakwe i-nitride. Ukumelana nokugqwala kwezinto eziphathwe ngale ndlela kunokunciphisa kangangokuba zingonakaliswa kwindawo yokuhlambela.
Musa ukusebenzisa izixhobo zesinyithi zentsimbi kwiimeko zeworkshop ezingacocekanga kangako. Iitships zentsimbi zinokuphetshwa ngokusebenzisa izixhobo ze-carbide okanye ze-ceramic.
Qaphela ukuba ukugqwala kungenzeka kwindawo yokuhlambela ukuba inxalenye ayilungiswanga kakuhle ngobushushu. Amanqanaba eMartensitic anomxholo ophezulu wekhabhoni kunye nechromium kufuneka aqiniswe ukuze amelane nokugqwala.
Ukudlulisa umoya kudla ngokwenziwa emva kokufudumala okulandelayo kumaqondo obushushu agcina ukumelana nokugqwala.
Musa ukungawunaki umlinganiselo we-nitric acid kwindawo yokuhlamba i-passivation. Kufuneka kuhlolwe rhoqo kusetyenziswa inkqubo elula ye-titration ecetyiswe nguCarpenter. Musa ukusebenzisa i-stainless steel ngaphezulu kwesinye ngexesha. Oku kuthintela ukudideka okubiza kakhulu kwaye kuthintela ukusabela kwe-galvanic.
Malunga nababhali: UTerry A. DeBold yingcali ye-R&D ye-Stainless Steel Alloys kwaye uJames W. Martin yingcali ye-Bar Metallurgy kwiCarpenter Technology Corp.(Reading, ePennsylvania).
Ingakanani? Ingakanani indawo endiyidingayo? Zeziphi iingxaki zokusingqongileyo endiya kujongana nazo? Ingakanani indlela yokufunda ende? Yintoni kanye kanye i-anodizing? Apha ngezantsi ziimpendulo zemibuzo yokuqala yeengcali malunga ne-anodizing yangaphakathi.
Ukufumana iziphumo ezihambelanayo nezisemgangathweni ophezulu kwinkqubo yokusila engenaziko kufuna ukuqonda okusisiseko. Uninzi lweengxaki zokusetyenziswa ezinxulumene nokusila okungenaziko zivela ekungaziqondini iziseko. Eli nqaku lichaza isizathu sokuba inkqubo engenaziko isebenze kunye nendlela yokuyisebenzisa ngokufanelekileyo kwindawo yakho yokusebenzela.