1. Uvavanyo lwethiyori kunye nohlalutyo
Kwesi-3iivalve zamatayaraiisampulu ezibonelelwe yinkampani, i-2 ziivalvu, kwaye i-1 yivalve engekasetyenziswa okwangoku.Ku-A no-B, ivalve engasetyenziswanga imakishwa njengengwevu.Umzobo obanzi 1. Umphandle wevalve A awunzulwanga, umphandle wevalve B ngumphezulu, umphandle wevalve C ngumphezulu, kwaye umphandle wevalve C ngumphezulu.Iivalvu A kunye no-B zigqunywe ngeemveliso zomhlwa.Ivalve A kunye no-B ziqhekeziwe ekugobeni, indawo engaphandle yegophe isecaleni kwevalve, ivalve ring umlomo B iqhekeziwe ukuya esiphelweni, kwaye utolo olumhlophe phakathi kweendawo eziqhekekileyo kumphezulu wevalve iphawulwe. .Ukusuka apha ngasentla, iintanda zikhona kuyo yonke indawo, iintanda zezona zikhulu, kwaye iintanda zikhona kuyo yonke indawo.
Icandelo leivalve yetayaraIisampuli ze-A, B, kunye ne-C zanqunyulwa kwi-bend, kwaye i-morphology ye-surface yabonwa nge-ZEISS-SUPRA55 yokuskena i-electron microscope, kwaye ukubunjwa kwendawo encinci kuhlalutywe nge-EDS.Umzobo 2 (a) ubonisa i-microstructure yendawo yevalve B.Ingabonwa ukuba kukho iinqununu ezininzi ezimhlophe kunye ezikhanyayo phezu komhlaba (ezibonakaliswe ngeentolo ezimhlophe kumfanekiso), kwaye uhlalutyo lwe-EDS lwamaqhekeza amhlophe lunomxholo ophezulu we-S. Iziphumo zohlalutyo lwe-energy spectrum ze-white particles ziboniswe kuMfanekiso 2(b).
Amanani 2 (c) kunye (e) lulwakhiwo olungaphezulu lwe-microstructures yevalvu B. Inokubonwa kuMfanekiso 2 (c) ukuba umphezulu uphantse wagqunywa zimveliso ezidlekayo, kunye nezinto ezidlekayo zeemveliso zomhlwa ngohlalutyo lwe-spectrum yamandla. ikakhulu zibandakanya i-S, i-Cl kunye ne-O, umxholo we-S kwizikhundla zomntu ngamnye uphezulu, kwaye iziphumo zohlalutyo lwe-spectrum yamandla ziboniswa kwi-Fig. 2 (d).Inokubonwa kuMzobo 2(e) ukuba kukho iintanda ezincinci ecaleni kweringi yevalvu kumphezulu wevalve A. Amanani 2(f) kunye no (g) ziimophologies zomhlaba zevalve C, umphezulu nawo igutyungelwe ngokupheleleyo yimveliso ye-corrosion, kunye ne-corrosion elements nayo ibandakanya i-S, i-Cl kunye ne-O, efana ne-Figure 2 (e).Isizathu sokuqhekeka sinokuba yi-stress corrosion cracking (SCC) ukusuka kuhlalutyo lwemveliso ye-corrosion kwi-valve surface.Umzobo we-2 (h) kwakhona i-microstructure yomphezulu we-valve C. Ingabonwa ukuba umphezulu ucocekile, kwaye i-chemical composition of the surface ehlalutywe yi-EDS ifana ne-alloy yobhedu, ebonisa ukuba i-valve. ayidlwengulwanga.Ngokuthelekisa i-microscopic morphology kunye nokwakhiwa kweekhemikhali zeendawo ezintathu zevalve, kuboniswa ukuba kukho imidiya ephazamisayo efana ne-S, O kunye ne-Cl kwindawo engqongileyo.
Ukuqhekeka kwevalve B kwavulwa ngovavanyo lokugoba, kwaye kwafunyaniswa ukuba ukuqhekeka akuzange kungene kulo lonke icandelo elinqamlezayo levalve, liqhekeke kwicala le-backbend, kwaye alizange liqhekeke kwicala elijongene ne-backbend. yevalve.Ukuhlolwa okubonakalayo kokuqhekeka kubonisa ukuba umbala we-fracture umnyama, obonisa ukuba i-fracture iye yatshitshiswa, kwaye ezinye iindawo zokuqhekeka zinombala omnyama, obonisa ukuba ukubola kubi kakhulu kula macandelo.Ukwaphuka kwevalve B kuye kwaqatshelwa phantsi kwe-electron yokuskena imakroskopu, njengoko kubonisiwe kuMfanekiso 3. Umzobo 3 (a) ubonisa inkangeleko enkulu yokwaphuka kwevalve B.Ingabonwa ukuba i-fracture yangaphandle kufuphi ne-valve igutyungelwe yimveliso ye-corrosion, iphinda ibonise ubukho beendaba ezinobungozi kwindawo engqongileyo.Ngokutsho kohlalutyo lwe-spectrum yamandla, iikhemikhali zemveliso ye-corrosion ziyi-S, Cl kunye ne-O, kunye neziqulatho ze-S kunye ne-O ziphezulu, njengoko kuboniswe kwi-Fig. 3 (b).Ukujonga umphezulu wokwaphuka, kufunyaniswe ukuba ipateni yokukhula kokuqhekeka isecaleni kohlobo lwekristale.Inani elikhulu leentanda zesibini nazo zingabonwa ngokuqwalasela ukuphuka kwi-magnifications ephezulu, njengoko kubonisiwe kuMfanekiso 3 (c).Iintanda zesibini ziphawulwe ngeentolo ezimhlophe kumfanekiso.Iimveliso ze-Corrosion kunye neepateni zokukhula kwe-crack kwindawo yokuphuka kwakhona zibonisa iimpawu zoxinzelelo lwe-corrosion cracking.
Ukuqhekeka kwevalve A ayikavulwa, susa icandelo levalve (kubandakanya indawo eqhekekileyo), ugaye kwaye upholise icandelo le-axial yevalve, kwaye usebenzise i-Fe Cl3 (5 g) + HCl (50 mL) + C2H5OH ( Isisombululo se-100 mL) sabhalwa, kwaye ubume bemetallographic kunye ne-crack growth morphology yabonwa nge-Zeiss Axio Observer A1m optical microscope.Umzobo 4 (a) ubonisa i-metallographic structure yevalve, eyi-α+β ye-dual-phase structure, kunye ne-β ilungile kwaye i-granular kwaye isasazwe kwi-matrix yesigaba se-α.Iipateni zokusasazwa kwee-crack kwii-cracks ezijikelezayo ziboniswa kuMfanekiso 4 (a), (b).Kuba imiphezulu yokuqhekeka izaliswe ziimveliso zomhlwa, umsantsa phakathi kwemiphezulu emibini yokuqhekeka ubanzi, kwaye kunzima ukwahlula iipateni zokusasaza kweentanda.i-bifurcation phenomenon.Iintanda ezininzi zesibini (eziphawulwe ngeentolo ezimhlophe emfanekisweni) nazo zabonwa kolu qhekeko oluphambili, jonga umzobo 4 (c), kwaye ezi zintlukwano zesibini zasasazwa ecaleni kwengqolowa.Isampulu yevalve echongiweyo yabonwa yi-SEM, kwaye kwafunyaniswa ukuba kukho iintanda ezininzi ezincinci kwezinye izikhundla ezihambelana nokuqhekeka okuphambili.Ezi crack ezincinci zisuka phezulu kwaye zanda ukuya ngaphakathi kwivalve.Iintanda zazicandeke kabini zaza zanda ecaleni kweenkozo, jonga uMfanekiso 4 (c), (d).Imeko-bume kunye noxinzelelo lwemeko yezi microcracks ziphantse zifane nezo zoqhekeko oluphambili, ngoko ke kunokuthatyathelwa ukuba uhlobo losasazo lwecrack oluphambili lukwaphakathi kwegranular, nto leyo ikwangqinwa kukujongwa kokwaphuka kwevalve B. I-bifurcation phenomenon ye Ukuqhekeka kwakhona kubonisa iimpawu zoxinzelelo lwe-corrosion cracking yevalve.
2. Uhlalutyo kunye neNgxoxo
Ukushwankathela, kunokuchazwa ukuba umonakalo wevalve ubangelwa kukuqhekeka kwe-corrosion yoxinzelelo olubangelwa yi-SO2.Uxinzelelo lwe-corrosion cracking ngokubanzi lufuna ukuhlangabezana neemeko ezintathu: (1) izinto ezithintekayo kuxinzelelo lwe-corrosion;(2) i-corrosive medium sensitive to copper alloys;(3) iimeko ezithile zoxinzelelo.
Ngokuqhelekileyo kukholelwa ukuba iintsimbi ezicocekileyo azikhathazwa kukuhlwa koxinzelelo, kwaye zonke i-alloys zisengozini yoxinzelelo lwe-corrosion ukuya kumaqondo ahlukeneyo.Kwizinto zobhedu, ngokuqhelekileyo kukholelwa ukuba isakhiwo sesigaba sesibini sinoxinzelelo oluphezulu lwe-corrosion susceptibility kunesakhiwo sesigaba esisodwa.Kuye kwaxelwa kwiincwadi ukuba xa umxholo we-Zn kwizinto zobhedu zidlula i-20%, unoxinzelelo oluphezulu lwe-corrosion susceptibility, kwaye iphakamileyo umxholo we-Zn, uphezulu ukuxhatshazwa kwe-corrosion susceptibility.Isakhiwo se-metallographic ye-gas nozzle kule meko yi-alpha + β-double-phase alloy, kwaye umxholo we-Zn umalunga ne-35%, ugqithise kakhulu i-20%, ngoko unoxinzelelo oluphezulu lwe-corrosion sensitivity kwaye ihlangabezana neemeko eziphathekayo ezifunekayo kuxinzelelo. ukuqhekeka komhlwa.
Kwimathiriyeli yobhedu, ukuba i-annealing yokunciphisa uxinzelelo ayenziwa emva kokuguqulwa kokusebenza okubandayo, i-corrosion yoxinzelelo iya kwenzeka phantsi kweemeko ezifanelekileyo zoxinzelelo kunye neendawo ezinobungozi.Uxinzelelo olubangela uxinzelelo lwe-corrosion cracking ngokubanzi luxinzelelo lwe-tensile yendawo, enokuthi isetyenziswe uxinzelelo okanye uxinzelelo olushiyekileyo.Emva kokuba itayara lelori livuthelwe umoya, uxinzelelo luya kuveliswa ecaleni kwe-axial ye-nozzle yomoya ngenxa yoxinzelelo oluphezulu kwitayara, okuya kubangela iintanda ezijikelezayo kumlomo womoya.Uxinzelelo loxinzelelo olubangelwa luxinzelelo lwangaphakathi lwetayara lunokubalwa ngokulula ngokwe σ=p R/2t (apho i-p iluxinzelelo lwangaphakathi lwetayara, R yidayamitha yangaphakathi yevalve, kwaye t bubunzima bodonga ivalve).Nangona kunjalo, ngokubanzi, ukunyanzeliswa koxinzelelo olwenziwa luxinzelelo lwangaphakathi lwesondo alukhulu kakhulu, kwaye umphumo woxinzelelo olushiyekileyo kufuneka uqwalaselwe.Izikhundla eziqhekekileyo zemibhobho yerhasi zonke zikwi-backbend, kwaye kuyacaca ukuba i-deformation eseleyo kwi-backbend inkulu, kwaye kukho uxinzelelo olushiyekileyo apho.Enyanisweni, kwizinto ezininzi ezisebenzayo ze-alloy copper, i-corrosion cracking yoxinzelelo ayifane ibangelwe luxinzelelo loyilo, kwaye uninzi lwazo lubangelwa luxinzelelo olushiyekileyo olungabonakali kwaye lungahoywa.Kule meko, kwi-bend yangasemva yevalve, isalathiso soxinzelelo loxinzelelo olwenziwa luxinzelelo lwangaphakathi lwetayara luhambelana nesalathiso soxinzelelo olushiyekileyo, kwaye ukuphakama kwezi zixinzelelo zimbini kubonelela ngemeko yoxinzelelo kwi-SCC. .
3. Isiphelo kunye neeNgcebiso
Isiphelo:
Ukuqhekeka kweivalve yetayaraibangelwa ikakhulu kukuqhekeka koxinzelelo lwe-corrosion olubangelwa yi-SO2.
Ingcebiso
(1) Landela umthombo wendlela eyingozi kwindalo esingqongileyoivalve yetayara, kwaye uzame ukunqanda ukudibana ngokuthe ngqo nesixhobo esirhangqe esonakalisayo.Ngokomzekelo, umaleko we-anti-corrosion coating ungafakwa kumphezulu wevalve.
(2) Ukuxinezeleka okushiyekileyo kokusebenza okubandayo kunokupheliswa ngeenkqubo ezifanelekileyo, ezifana nokunciphisa uxinzelelo emva kokugoba.
Ixesha lokuposa: Sep-23-2022