1. Ukuhlolwa Nokuhlaziywa Kwethiyori
Kwezingu-3amavalvu amathayiAmasampula anikezwe yinkampani, ama-2 angama-valve, kanti eli-1 liyi-valve engakasetshenziswa. Ku-A no-B, i-valve engakasetshenziswa imakwe njengempunga. Isithombe Esiphelele 1. Ubuso bangaphandle be-valve A abujulile, ubuso bangaphandle be-valve B bungaphezulu, ubuso bangaphandle be-valve C bungaphezulu, kanti ubuso bangaphandle be-valve C bungaphezulu. Ama-valve A no-B ambozwe ngemikhiqizo yokugqwala. I-valve A no-B baqhekekile emagobeni, ingxenye engaphandle ye-bend iseduze ne-valve, umlomo wendandatho ye-valve B uqhekekile ekugcineni, futhi umcibisholo omhlophe phakathi kwezindawo eziqhekekile ebusweni be-valve A uphawulwe. Kusukela ngenhla, imifantu ikhona yonke indawo, imifantu inkulu kunayo yonke, kanti imifantu ikhona yonke indawo.
Ingxenye yeivalvu yethayiAmasampula e-A, B, kanye ne-C asikwe kusukela ekugobeni, futhi isimo sobuso sabonwa nge-microscope ye-electron yokuskena ye-ZEISS-SUPRA55, futhi ukwakheka kwendawo encane kwahlaziywa nge-EDS. Isithombe 2 (a) sibonisa isakhiwo esincane sobuso be-valve B. Kungabonakala ukuthi kunezinhlayiya eziningi ezimhlophe nezikhanyayo ebusweni (okuboniswe yimicibisholo emhlophe esithombeni), futhi ukuhlaziywa kwe-EDS kwezinhlayiya ezimhlophe kunokuqukethwe okuphezulu kwe-S. Imiphumela yokuhlaziywa kwe-energy spectrum yezinhlayiya ezimhlophe iboniswe ku-Figure 2 (b).
Izibalo 2 (c) kanye no-(e) ziyizakhiwo ezincane zobuso be-valve B. Kungabonakala ku-Figure 2 (c) ukuthi ubuso bumbozwe cishe ngokuphelele yimikhiqizo yokugqwala, kanti izakhi ezigqwalisayo zemikhiqizo yokugqwala ngokuhlaziywa kwe-energy spectrum zifaka phakathi i-S, Cl kanye ne-O, okuqukethwe yi-S ezindaweni ngazinye kuphakeme, kanti imiphumela yokuhlaziywa kwe-energy spectrum iboniswe ku-Fig. 2(d). Kungabonakala ku-Figure 2(e) ukuthi kunemifantu emincane eceleni kwendandatho ye-valve ebusweni be-valve A. Izibalo 2(f) kanye no-(g) ziyi-surface micro-morphology ye-valve C, ubuso bumbozwe ngokuphelele yimikhiqizo yokugqwala, kanti izakhi ezigqwalisayo nazo zifaka i-S, Cl kanye ne-O, efana ne-Figure 2(e). Isizathu sokugqwala kungaba ukugqwala kwe-stress corrosion (SCC) okuvela ekuhlaziyweni komkhiqizo wokugqwala ebusweni be-valve. Isithombe 2(h) siphinde sibe yisakhiwo esincane sobuso be-valve C. Kungabonakala ukuthi ubuso buhlanzekile, futhi ukwakheka kwamakhemikhali kobuso obuhlaziywe yi-EDS kufana nokwe-alloy yethusi, okubonisa ukuthi i-valve ayigqwali. Ngokuqhathanisa isimo se-microscopic kanye nokwakheka kwamakhemikhali kobuso be-valve ezintathu, kuboniswa ukuthi kunemidiya egqwalizayo njenge-S, O kanye ne-Cl endaweni ezungezile.
Uqhekeko lwe-valve B luvulwe ngokuhlolwa kokugoba, kwatholakala ukuthi uqhekeko alungenanga engxenyeni yonke ye-valve, luqhekekile ohlangothini lwe-backbend, futhi aluqhekekanga ohlangothini oluphambene ne-backbend ye-valve. Ukuhlolwa okubonakalayo kokuqhekeka kukhombisa ukuthi umbala wokuqhekeka umnyama, okubonisa ukuthi ukuqhekeka kugqwalile, kanti ezinye izingxenye zokuqhekeka zinombala omnyama, okubonisa ukuthi ukugqwala kubi kakhulu kulezi zingxenye. Ukuqhekeka kwe-valve B kubonwe ngaphansi kwe-scanning electron microscope, njengoba kuboniswe kuMfanekiso 3. Umfanekiso 3 (a) ukhombisa ukubukeka okukhulu kokuqhekeka kwe-valve B. Kungabonakala ukuthi ukuqhekeka kwangaphandle eduze kwe-valve kumbozwe imikhiqizo yokugqwala, okubonisa futhi ukuba khona kwemidiya egqwalisayo endaweni ezungezile. Ngokusho kokuhlaziywa kwe-energy spectrum, izingxenye zamakhemikhali zomkhiqizo wokugqwala ikakhulukazi yi-S, Cl kanye ne-O, kanti okuqukethwe yi-S kanye ne-O kuphakeme kakhulu, njengoba kuboniswe kuMfanekiso 3(b). Uma kubhekwe ubuso bokuqhekeka, kutholakala ukuthi iphethini yokukhula kokuqhekeka ihambisana nohlobo lwekristalu. Inani elikhulu lemifantu yesibili lingabonakala nangokubona ukuphuka ekukhulisweni okuphezulu, njengoba kuboniswe kuMfanekiso 3(c). Imifantu yesibili imakwe ngemicibisholo emhlophe esithombeni. Imikhiqizo yokugqwala kanye namaphethini okukhula kwemifantu ebusweni bokuqhekeka futhi abonisa izici zokuqhekeka kokugqwala kokucindezeleka.
Ukuphuka kwevalvu A akukavulwa, susa ingxenye yevalvu (kufaka phakathi indawo eqhekekile), gaya bese upholisha ingxenye ye-axial yevalvu, bese usebenzisa isixazululo se-Fe Cl3 (5 g) +HCl (50 mL) + C2H5OH (100 mL) saqoshwa, futhi isakhiwo se-metallographic kanye nesimo sokukhula kwe-crack kwabonwa nge-microscope ye-optical ye-Zeiss Axio Observer A1m. Isithombe 4 (a) sibonisa isakhiwo se-metallographic sevalvu, okuyisakhiwo se-α+β esinezigaba ezimbili, kanti i-β incane futhi i-granular futhi isatshalaliswa ku-matrix yesigaba se-α. Amaphethini okusabalala kwe-crack emifantwini ejikelezayo aboniswe ku-Figure 4(a), (b). Njengoba izindawo zokuqhekeka zigcwele imikhiqizo yokugqwala, igebe phakathi kwezindawo ezimbili zokuqhekeka libanzi, futhi kunzima ukuhlukanisa amaphethini okusabalala kwe-crack. Isenzakalo sokuqhekeka kwe-bifurcation. Imifantu eminingi yesibili (ephawulwe ngemicibisholo emhlophe esithombeni) nayo yabonwa kulo mfantu oyinhloko, bheka i-Fig. 4(c), futhi le mifantu yesibili yasakazeka eceleni kwenhlamvu. Isampula yevalvu eqoshiwe yabonwa yi-SEM, futhi kwatholakala ukuthi kwakunemifantu eminingi emincane kwezinye izikhundla ezihambisana nomfantu oyinhloko. Le mifantu emincane yaqala ebusweni futhi yanda yaya ngaphakathi kwevalvu. Imifantu yayine-bifurcation futhi yanda eceleni kwenhlamvu, bheka Umfanekiso 4 (c), (d). Indawo kanye nesimo sokucindezeleka sale mifantu emincane cishe sifana nesomfantu oyinhloko, ngakho-ke kungacatshangwa ukuthi ifomu lokusabalala komfantu oyinhloko nalo liphakathi kwe-granular, okuqinisekiswa futhi ngokubona ukuphuka kwevalvu B. Isenzakalo sokuhlukana komfantu sibonisa futhi izici zokuqhekeka kokugqwala kokucindezeleka kwevalvu.
2. Ukuhlaziywa kanye Nengxoxo
Ngamafuphi, kungaphethwa ngokuthi umonakalo wevalvu ubangelwa ukuqhekeka kokugqwala kokucindezeleka okubangelwa yi-SO2. Ukuqhekeka kokugqwala kokucindezeleka ngokuvamile kudinga ukuhlangabezana nezimo ezintathu: (1) izinto ezizwela ukugqwala kokucindezeleka; (2) ukugqwala okuphakathi okuzwela ama-alloy ethusi; (3) izimo ezithile zokucindezeleka.
Ngokuvamile kukholelwa ukuthi izinsimbi ezimsulwa azihlushwa ukugqwala kokucindezeleka, futhi zonke izinhlobo ze-alloy zisengozini yokugqwala kokucindezeleka ngamazinga ahlukahlukene. Ngokwezinto zethusi, ngokuvamile kukholelwa ukuthi isakhiwo sesigaba esiphindwe kabili sinokuthambekela kokugqwala kokucindezeleka okuphezulu kunesakhiwo sesigaba esisodwa. Kuye kwabikwa ezincwadini ukuthi lapho okuqukethwe yi-Zn ezintweni zethusi kudlula u-20%, kunokuthambekela kokugqwala kokucindezeleka okuphezulu, futhi uma okuqukethwe yi-Zn kuphakeme, kulapho ukuthambekela kokugqwala kokucindezeleka kuphakeme khona. Isakhiwo se-metallographic se-nozzle yegesi kulokhu kuyi-alloy yesigaba esiphindwe kabili ye-α+β, kanti okuqukethwe yi-Zn kucishe kube ngu-35%, kudlula kakhulu u-20%, ngakho-ke sinokuthambekela kokugqwala kokucindezeleka okuphezulu futhi kuhlangabezana nezimo zezinto ezidingekayo ukuze kuqhekeke ukugqwala kokucindezeleka.
Kwizinto zethusi, uma ukuncishiswa kokucindezeleka kungenziwa ngemva kokuguquguquka kokusebenza okubandayo, ukugqwala kokucindezeleka kuzokwenzeka ngaphansi kwezimo ezifanele zokucindezeleka kanye nezimo ezigqwalisayo. Ukucindezeleka okubangela ukuqhekeka kokugqwala kokucindezeleka ngokuvamile ukucindezeleka kokuthamba kwendawo, okungasetshenziswa ukucindezeleka noma ukucindezeleka okusele. Ngemva kokuba ithayi leloli likhuphukile, ukucindezeleka kokuthamba kuzokhiqizwa eceleni kwendlela ye-axial ye-nozzle yomoya ngenxa yokucindezela okuphezulu ethayi, okuzobangela ukuqhekeka okujikelezayo e-nozzle yomoya. Ukucindezeleka kokuthamba okubangelwa ukucindezela kwangaphakathi kwethayi kungabalwa kalula ngokusho kwe-σ=p R/2t (lapho i-p iyingcindezi yangaphakathi yethayi, i-R iyi-diameter yangaphakathi ye-valve, kanye ne-t iyi-wall thickness ye-valve). Kodwa-ke, ngokuvamile, ukucindezeleka kokuthamba okubangelwa ukucindezela kwangaphakathi kwethayi akukukhulu kakhulu, futhi umphumela wokucindezeleka okusele kufanele ucatshangelwe. Izindawo zokuqhekeka kwama-nozzle egesi zonke zise-backbend, futhi kusobala ukuthi ukuguquguquka okusele e-backbend kukhulu, futhi kukhona ukucindezeleka kokuthamba okusele lapho. Eqinisweni, ezingxenyeni eziningi ze-alloy yethusi ezisebenzayo, ukuqhekeka kokugqwala kokucindezeleka akuvamile ukubangelwa ukucindezeleka komklamo, futhi iningi lazo libangelwa ukucindezeleka okusalayo okungabonakali futhi okunganakwa. Kulokhu, ekugobeni kwangemuva kwevalvu, isiqondiso sokucindezeleka kokucindezela okubangelwa ukucindezela kwangaphakathi kwethayi sihambisana nesiqondiso sokucindezeleka okusalayo, futhi ukufakwa kwalezi zingcindezi ezimbili kunikeza isimo sokucindezeleka se-SCC.
3. Isiphetho kanye Neziphakamiso
Isiphetho:
Ukuqhekeka kweivalvu yethayiikakhulukazi kubangelwa ukuqhekeka kokugqwala kokucindezeleka okubangelwa yi-SO2.
Isiphakamiso
(1) Landela umthombo wendawo egqwalisayo endaweni ezungezileivalvu yethayi, futhi zama ukugwema ukuthintana ngqo nendawo egqwalisayo ezungezile. Isibonelo, ungqimba lwesembozo esilwa nokugqwala lungasetshenziswa ebusweni bevalvu.
(2) Ukucindezeleka okusele kokucindezeleka kokusebenza okubandayo kungasuswa ngezinqubo ezifanele, njengokunciphisa ukucindezeleka ngemva kokugoba.
Isikhathi sokuthunyelwe: Septhemba-23-2022
