Ihe na-akpata nchara na nchara n'ụlọ elu jụrụ oyi mgbe ọtụtụ afọ nke ọrụ gasịrị

 

 

 

 

 

 

I. Core Corrosion Mechanism: Electrochemical Corrosion na-achịkwa usoro nke nchara na nchara

 

 

 

 

 

A na-ekpughere akụkụ igwe nke ụlọ elu jụrụ oyi (karịsịa carbon steel na galvanized steel) na mmiri- ikuku ikuku ruo ogologo oge, ebe ọtụtụ mkpụrụ ndụ micro galvanic na-adị mfe n'elu, na-ebute corrosion electrochemical na-aga n'ihu - isi ihe na-akpata nchara na nchara.

 

Atọm ígwè dị na mpaghara anode na-enweta mmeghachi omume oxidation wee jiri nwayọọ nwayọọ na-agbaze n'ime ion ígwè (Fe → Fe²⁺ + 2e⁻), na-eme ka ọkpụkpụ ígwè na-efunahụ ya; Mbelata mmeghachi omume na-eme na mpaghara cathode, ebe ikuku oxygen gbazere na mmiri na-ejikọta ya na electrons iji mepụta ion hydroxide (O₂ + 2H₂O + 4e⁻ → 4OH⁻), na-aga n'ihu na-ebute mmeghachi omume corrosion.

 

 

Ferrous hydroxide [Fe(OH)₂] nke mmeghachi omume corrosion mepụtara na-eme ka ọ bụrụ ferric hydroxide [Fe (OH)₃], na-emecha na-akpụ nchara na-adịghị na ya. N'adịghị ka nnukwu metal oxide fim, nchara enweghị ike inye nchebe; Kama nke ahụ, ọ na-eme ka mmiri na ikuku oxygen na-eme ka ọ dịkwuo mma, na-eme ka corrosion nke oyi akwa metal dị n'ime ngwa ngwa.

 

 

Karịsịa mgbe ion chloride dị n'ime mmiri, ha na-abanye ngwa ngwa na fim passivation nke dị n'elu igwe ka ọ na-emepụta mkpụrụ ndụ kpuchiri ekpuchi, na-eme ka nsị nke ime obodo.

 

 

Ka olulu na-emikpu n'ihu na-aga n'ihu, perforation na-emecha na-etolite, nke bụ isi ihe na-ebute obere oge{{0} perforation n'ọtụtụ ụlọ elu jụrụ oyi.

 

 

 

 

 

 

II. Isi ihe anọ na-eme ngwa ngwa: igodo iji mee nchara nchara ngwa ngwa n'ime afọ 3-5

 

(1) Mbelata ogo mmiri na-ekesa na-abawanye oke nrụrụ

 

 

 

 

 

 

Mmiri na-ekesa na-arụ ọrụ dị ka "ihe na-eme ka ụlọ elu dị jụụ corrosion. Ọdịmma mmiri na-emebi emebi na-eme ka nrụrụ igwe dịkwuo ngwa ngwa ma bụrụ ihe kacha mkpa na-eme ngwa ngwa. N'oge a na-arụ ọrụ ụlọ elu jụrụ oyi, ikuku mmiri na-aga n'ihu na-eduga na ntinye nke nnu dị ka ion chloride na sulfate radicals na mmiri, na-abawanye conductivity mmiri nke ọma ma na-ebuli ọnụego corrosion electrochemical site ugboro 3 ruo 5.

 

 

Ka ọ dị ugbu a, uru pH na-achịkwaghị achịkwa nke mmiri na-ekesa na-eme ka corrosion dịkwuo njọ: mgbe pH dị n'okpuru 6.5, mmiri ahụ bụ acidic ma na-agbari matrix metal ozugbo; Mgbe pH karịrị 9, ọnụ ọgụgụ dị mfe na-etolite. Ọnụ ọgụgụ nke ikpuchi elu igwe na-akpata n'okpuru- corrosion nkwụnye ego, na-ekepụta ọdịiche nke ikuku oxygen na mpaghara yana na-eme ka nchara dị ngwa.

 

 

 

 

 

Tụkwasị na nke ahụ, usoro ịgbasa na ikuku nke ụlọ elu jụrụ oyi na-eme ka ikuku oxygen gbazee na mmiri (na-emekarị 8-10 mg / L), na-eme ka mmeghachi omume cathode sie ike ma na-akwalite corrosion na-aga n'ihu. Microorganisms dị ka nje bacteria na algae dị na mmiri na-etolite biofilms, na metabolism ha na-emepụta ihe acidic dị ka hydrogen sulfide, na-emebi ihe nkiri passivation n'elu ígwè ma na-eme ka mmebi nke mpaghara dịkwuo elu.

 

 

 

(2) Mgbochi mbụ nke Mgbochi{{1}Mkpuchi corrosion na-anapụ ọla mgbochi mgbochi.

 

 

 

 

Mgbochi{{0}corrosion n'elu ihe igwe igwe na-ajụ oyi na-arụ ọrụ dị ka ahịrị mbụ nke nchebe megide corrosion. Mkpuchi mkpuchi n'oge na-ekpughe ọla ozugbo na gburugburu ebe ndị na-emebi emebi, na-eduga nchara ngwa ngwa.

 

mkpuchi mkpuchi na-esite n'akụkụ atọ: nke mbụ, mmebi iwu - n'oge echichi, ọtụtụ ụlọ elu jụrụ oyi nwere ezughị ezu metal n'elu derusting (emezughị ụkpụrụ Sa2.5), na-akpata na-adịghị mma adhesion n'etiti coatings na metal matrices, na ụdi cracking na peeling; nke abụọ, mmebi gburugburu ebe obibi - ultraviolet radieshon, mgbanwe okpomọkụ nke ụbọchị ọ bụla, ịcha mmiri na-asọpụta na ikpochapụ uzuzu n'ime oghere{1} ikuku ikuku na-eji nwayọọ nwayọọ na-aka nká na mkpuchi mkpuchi, na-emebi nchebe ha;

 

 

nke atọ, oghere nhazi - enweghị ike itinye mkpuchi na welds, flanges na nkwonkwo akụrụngwa, ebe mmiri na uzuzu na-agbakọta, na-aghọ "ebe ọdachi" nke corrosion nke nchara na mbụ wee jiri nwayọọ nwayọọ banye.

 

 

 

(3) ezughị oke dị n'ịhọrọ ihe na nhazi ihe mgbochi nrụrụ adịghị ike.

 

 

Nhọrọ ihe na-ezighi ezi bụ isi ihe dị mkpa maka obere oge{0} nchara nke ụlọ elu jụrụ oyi. Iji belata ọnụ ahịa, ọtụtụ ndị na-emepụta ihe na-eji ígwè carbon nkịtị ma ọ bụ ígwè galvanized nkịtị maka ụlọ elu, ihe nkwado na ihe ndị ọzọ, nke na-enwechaghị nguzogide corrosion, karịsịa na gburugburu mmiri dị elu- nnu ma ọ bụ acidic nwere ọnụ ahịa nrụrụ ngwa ngwa.

 

Ezughị oke galvanized oyi akwa na substandard galvanizing Filiks na-akpata ngwa ngwa eyi na peeling nke galvanized n'ígwé, adịkwa ha nchebe mmetụta. Ka ọ dị ugbu a, nhazi ụlọ elu jụrụ oyi na-enweghị ezi uche, dị ka oghere dị ukwuu na nkwonkwo akụrụngwa yana mmiri na-adịghị mma, na-eduga n'ịgbakọta mmiri ogologo oge na gburugburu ebe na-emebi emebi. Nhazi na-ezighi ezi nke akụkụ ikuku nke ụlọ elu ahụ na-akpata ọgba aghara ikuku, na-eme ka uzuoku mmiri na-akpụ akpụ na ọla ma na-akawanye njọ.

 

 

 

(4) Ịrụ ọrụ ezughị oke na nlekọta nlekọta na-eme ka nrụrụ ka njọ

 

 

 

Ọtụtụ ndị ọrụ na-eleghara ọrụ kwa ụbọchị na ịrụzi ụlọ elu jụrụ oyi, na-ahapụ nsogbu corrosion na-achọpụtaghị na nke a na-achịkwaghị achịkwa, na-emecha na-etolite ngwa ngwa n'ime perforation.

 

Mmebi mmezi a na-ahụkarị gụnyere: ịghara ịnwale mgbe niile ịdị mma mmiri na-ekesa ma tinye ihe mgbochi corrosion na ihe mgbochi ọnụ n'oge, na-eduga n'ịdị mma mmiri na-aga n'ihu;

 

ịghara ịdị na-ehicha ọnụ ọgụgụ mgbe niile, ihe nkiri biofilms na irighiri ihe dị n'ime ụlọ elu ahụ, na-abawanye corrosion mpaghara; ọdịda na-enyocha ihe mgbochi - ihe mkpuchi corrosion na ịrụzi mgbawa na peeling n'oge, na-ekpughe ọla mgbe niile;

 

enweghị usoro mgbochi friza n'oge oyi, na-ebute mgbawa n'ime ihe ndị mejupụtara igwe n'ihi friza{0}} cycles na-aghọkwa isi mmalite maka corrosion.

 

 

 

III. Mmechi

 

 

Ọ bụghị otu ihe kpatara nchara na perforation n'ụlọ elu jụrụ oyi mgbe ọtụtụ afọ nke ọrụ gasịrị, ọ bụghị otu ihe kpatara ya, kama site na nchikota nke electrochemical corrosion dị ka isi, yana ogologo {{0}okwu superposition nke nbibi àgwà mmiri, ọdịda mkpuchi, ihe onwunwe na nhazi nhazi, yana arụ ọrụ na mmezi ezughị ezu.

 

 

Iji gbatịkwuo ndụ ụlọ elu jụrụ oyi, mbọ ga-amalite site na isi mmalite: ịhọrọ oke corrosion{0} ihe na-eguzogide ọgwụ, nhazi mgbochi{1} ihe owuwu corrosion, na-eme ka njikwa ogo mmiri na-ekesa ike, na-eduzi ọrụ kwa ụbọchị na nleba anya nrụzi, na ileba anya n'ihe ize ndụ corrosion zoro ezo n'oge. Naanị n'ụzọ dị otú a ka a ga-esi belata ọnụ ọgụgụ corrosion nke ọma ma gbanarị nchara nchara na perforation.