Umhlwa ngumonakalo okanye ukuwohloka kwemathiriyeli okanye iipropathi zazo ezibangelwa sisenzo sokusingqongileyo.Uninzi lwe-corrosion lwenzeka kwindawo ye-atmospheric, equkethe amacandelo e-corrosion kunye nezinto eziphazamisayo ezifana ne-oxygen, ukufuma, utshintsho lobushushu kunye nezinto ezingcolileyo.
Umhlwa wokutshizwa kwetyuwa lolona hlobo luqhelekileyo nolona luyonakalisayo lwe-atmospheric corrosion.Ityuwa yokutshiza ityuwa kumphezulu wezinto zetsimbi ibangelwa yi-ion yekloride equlethwe kwindawo yesinyithi engena nge-oxidation layer kunye ne-protection layer kunye ne-metal electrochemical reaction yangaphakathi.Kwangaxeshanye, i-ion ye-chloride iqulethe umlinganiselo othile wamandla e-hydration, ekulula ukuba i-adsorbed kwi-metal surface pores kunye neentanda kunye nokubuyisela i-oksijini kwindawo ye-oxide, ngaloo ndlela iguqula i-oksidi engenakunyibilika ibe yi-chloride enyibilikayo kunye ne-passivated. chaza umphezulu kwindawo esebenzayo.
Ityuwaisitshizi sokukhusela umhlwaUvavanyo luvavanyo lokusingqongileyo olusebenzisa ubukhulu becala iimeko zokusingqongileyo ezilinganisiweyo zesitshizi setyuwa ezenziwe zizixhobo zovavanyo lokutshiza ngetyuwa ukuvavanya ukuxhathisa kokudleka kweemveliso okanye imathiriyeli yesinyithi.Yahlulwe yaba ziindidi ezimbini zovavanyo: uvavanyo lokuvezwa kokusingqongileyo kwendalo, kunye novavanyo olukhawulezileyo lokulinganisa lokusingqongileyo lwetyuwa lokutshiza.
Kuvavanyo lokusingqongileyo lokulinganisa lokutshiza ityuwa, igumbi lovavanyo lokutshiza ityuwa enomthamo othile wendawo liyasetyenziswa, kwaye imeko-bume yokutshiza ityuwa iveliswa ngokusebenzisa iindlela ezenziweyo kumthamo wayo wendawo, ukuze kuvavanywe ukusebenza kunye nomgangatho wokuthotywa kwetyuwa. ukumelana kweemveliso.
Umdibaniso wetyuwa wekloridi kwindawo yokutshiza ityuwa unokuba ngamaxesha aliqela okanye amaxesha amaninzi isiqulatho sokutshiza ngetyuwa kwindawo eqhelekileyo yendalo, ngaloo ndlela yandisa kakhulu isantya sokuhlwa kunye nokunciphisa kakhulu ixesha lokufumana iziphumo.Umzekelo, kungathatha unyaka omnye ukubola xa kuvavanywa isampulu yemveliso kwindawo yokuvezwa kwendalo, ngelixa ufumana iziphumo zovavanyo olufanayo emva nje kweeyure ezingama-24 kwindawo yokulinganisa eyenziweyo yokutshiza ityuwa.
Ilabhoratri efanisiweyo yokutshiza ityuwa inokohlulwa ngokweendidi ezine.
(1) Uvavanyo lokutshiza lwetyuwa olungathathi hlangothi (uvavanyo lwe-NSS) yeyona ndlela yakuqala kwaye isetyenziswa kakhulu ekuvavanyeni umhlwa okukhawulezileyo.Isebenzisa i-5% ye-sodium chloride isisombululo samanzi etyuwa, kunye nexabiso le-pH elilungelelanisiweyo kuluhlu olungathathi hlangothi (6.5 ~ 7.2) njengesisombululo sokutshiza.Ubushushu bovavanyo yi-35 ℃, kwaye izinga elifunekayo lentlenga yesitshizi setyuwa yi-1~2ml/80cm/h.
(2) Uvavanyo lwe-acetic acid yetyuwa yokutshiza (uvavanyo lwe-ASS) luphuhliswa ngesiseko sovavanyo lokutshiza lwetyuwa olungathathi hlangothi.Ikwisisombululo se-5% ye-sodium chloride kunye ne-acetic acid enomkhenkce, ukwenzela ukuba isisombululo se-PH sincitshiswe malunga ne-3, isisombululo siba ne-acidic, kwaye i-spray yetyuwa eyenziwe ekugqibeleni iba ne-acidic kwi-spray yetyuwa engathathi hlangothi.Izinga lokubola kwayo malunga namaxesha ama-3 ngokukhawuleza kunovavanyo lwe-NSS.
(3) Uvavanyo lwetyuwa lobhedu olukhawulezileyo lokutshiza i-acetate (uvavanyo lwe-CASS) luvavanyo olusanda kuphuhliswa lwangaphandle olukhawulezayo lokutshiza ityuwa.Ubushushu bovavanyo ngama-50 ℃.Isixa esincinci sobhedu setyuwa-i-chloride yethusi yongezwa kwisisombululo setyuwa ukuze sikhuthaze ngamandla ukubola.Izinga lokubola kwayo malunga namaxesha angama-8 kuvavanyo lwe-NSS.
(4) Uvavanyo lokutshiza ngetyuwa olutshintshanayo luvavanyo olubanzi lwesitshizi setyuwa, oluluvavanyo lokutshiza ngetyuwa olungathathi hlangothi kunye novavanyo oluqhubekayo lokufuma kunye nobushushu.Isetyenziselwa ubukhulu becala kwimveliso yohlobo lombhobho.Ngokugqobhoza kokusingqongileyo okuhamba namaza, ukonakala kwesitshizi setyuwa kuveliswa kungekuphela nje kumphezulu kodwa nangaphakathi kwimveliso.Imveliso iguqulwa ngokutshintshana phakathi kwetyuwa yokutshiza kunye nokufuma kunye nokusingqongileyo kobushushu, kwaye ke iimpawu zombane kunye nezomatshini zemveliso kufuneka zihlolwe naluphi na utshintsho.
Ukumiselwa kweziphumo
Iziphumo zovavanyo lovavanyo lwesitshizi setyuwa zinikwa ngokubanzi ngohlobo lomgangatho kunendlela yobungakanani.Kukho iindlela ezine ezikhethekileyo zokumisela.
(1) Indlela yokumisela umlinganiselo.
Kule ndlela, yahlula umlinganiselo wendawo ye-corrosion kunye nommandla opheleleyo kumanqanaba amaninzi, kwaye unqume inqanaba elithile njengesiseko esifanelekileyo sokumisela.Le ndlela ifanelekile kuvavanyo lweesampuli ezisicaba.
(2) Indlela yokumisela umlinganiselo.
Ngokulinganisa ubunzima besampulu ngaphambi nasemva kovavanyo lokuhlwa, bala ubunzima obulahlekileyo ngenxa yokuhlwa, kwaye ugwebeukhuselo lokutshizaumgangatho wesampuli.Le ndlela ifaneleke ngokukodwa ukuvavanya umgangatho othile wokumelana nokubola kwesinyithi.
(3) Indlela yohlalutyo lweenkcukacha-manani ze-Corrosion.
Le ndlela ibonelela ngenqanaba lokuzithemba lokuyila iimvavanyo ze-corrosion, ukuhlalutya idatha yokubola, kunye nokumisela idatha yokubola, esetyenziselwa kakhulu uhlalutyo kunye nezibalo zokubola, kunokuba ngokukodwa ukumiselwa komgangatho wemveliso.
Uvavanyo lwesitshizi setyuwa lwentsimbi engenanto
Ukusukela oko kwayilwa ekuqaleni kwenkulungwane yamashumi amabini, uvavanyo lwesitshizi setyuwa luye lwathandwa kakhulu ngabasebenzisi bezinto ezikwaziyo ukumelana nomhlwa ngenxa yeenzuzo zalo ezibandakanya ixesha elincitshisiweyo kunye neendleko, ezikwaziyo ukuvavanya izinto ezahlukeneyo, kunye nokubonelela ngeziphumo ezilula nezicacileyo.
Ngokwesiqhelo, uvavanyo lokutshiza ngetyuwa lolona lwaziwa kakhulu, kwaye iingcali kufuneka ziqhelane nokuba zingaphi iiyure uvavanyo lokutshiza ityuwa lunokuhlala kulo mbandela.
Abathengisi bezinto eziphathekayo baya kwandisa ixesha lokuvavanya ityuwa yokutshiza ngentsimbi engenasici ngeendlela ezinje nge-passivation okanye ukunyusa umgangatho wepolish.Nangona kunjalo, eyona nto ibalulekileyo yokumisela eyona nto kukubunjwa kwensimbi engenasici ngokwayo, oko kukuthi umxholo we-chromium, i-molybdenum kunye ne-nickel.
Okukhona uphezulu umxholo wazo zombini ichromium kunye nemolybdenum, kokukhona uxhathiso olukhulu lokutya olufunekayo kwimingxuma kunye nomhlwa oqala ukubonakala.Olu xhathiso lwe-corrosion lubonakaliswa yinto ebizwa ngokuba yi-pitting resistance equivalent (PRE) ixabiso: PRE = % Cr + 3.3 x % Mo.
Ngelixa i-nickel inganyusi ukuxhathisa kwentsimbi kwi-pitting kunye ne-crevice corrosion, inokusebenza ngokucothisa isantya sokubola emva kokuba inkqubo ye-corrosion iqalile.Ke ngoko, iintsimbi ze-austenitic ezingenazintsimbi ezine-nickel zikholisa ukwenza ngcono kakhulu kuvavanyo lwesitshizi setyuwa kunye nomhlwa ngaphantsi kakhulu kunezintsimbi ze-nickel ferritic ezingenazintsimbi ezinemibhobho efanayo yokuchasa.
Kufuneka kuqatshelwe ukuba ityuwaisitshizi sokukhusela umhlwauvavanyo lunezithintelo ezinkulu xa kuhlolwa ukusebenza kwentsimbi engenasici.Isiqulatho sekloridi yesitshizi setyuwa kuvavanyo lwesitshizi setyuwa siphezulu kakhulu kwaye singaphezulu lee kwimo engqongileyo yokwenyani, ngoko ke iintsimbi ezingenakutyiwa ezinokuxhathisa umhlwa kwizicelo ezizizo ezinomxholo ophantsi kakhulu wekloridi nazo ziya kugqwala kuvavanyo lwesitshizi setyuwa.
Uvavanyo lwesitshizi setyuwa luyayitshintsha indlela yokonakala kwentsimbi engatyiwayo, enokuthi ithathelwe ingqalelo njengovavanyo olukhawulezileyo okanye uvavanyo lokulinganisa.Iziphumo zicalanye kwaye azinabudlelwane obulinganayo kunye nokusebenza kwangempela kwensimbi engenasici ekugqibeleni isetyenziswe.
Ngoko ungasebenzisa uvavanyo lokutshiza ityuwa ukuthelekisa ukuxhathisa ukubola kweentlobo ezahlukeneyo zensimbi engenasici, kodwa olu vavanyo lukwazi ukukala kuphela izinto.Xa ukhetha into ethile yensimbi engenasici, uvavanyo lokutshiza ityuwa lulodwa aludli ngokunika ulwazi olwaneleyo ngenxa yokuba uxhulumaniso phakathi kweemeko zovavanyo kunye neyona ndawo yokusetyenziswa ayifane yaziwe.
Ukongeza, iindidi ezahlukeneyo zentsimbi azinakuthelekiswa nezinye, kuba izinto ezimbini ezisetyenzisiweyo kuvavanyo zineendlela ezahlukeneyo zokubola, ngoko ke iziphumo zovavanyo kunye nokubaluleka kokusetyenziswa kokugqibela kokusingqongileyo akufani.
Ixesha lokuposa: Jul-08-2022