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Insimbi engu-20MnTiB iyinto esetshenziswa kabanzi kakhulu yebhawodi enamandla amakhulu kumabhuloho esakhiwo sensimbi ezweni lami, futhi ukusebenza kwayo kubaluleke kakhulu ekusebenzeni okuphephile kwamabhuloho. Ngokusekelwe ophenyweni lwendawo yomoya e-Chongqing, lolu cwaningo luklame isixazululo sokugqwala esilingisa isimo sezulu esinomswakama sase-Chongqing, futhi lwahlola ukugqwala kwesimo sezulu esilinganisiwe esilinganisiwe. I-Chongqing.Imiphumela yezinga lokushisa, inani le-pH kanye nokugxiliswa kwesisombululo sokugqwala okulingiswayo ekuziphatheni kokugqwala kwengcindezi kwamabhawodi anamandla amakhulu angu-20MnTiB kuye kwacwaningwa.
Insimbi engu-20MnTiB iyinto esetshenziswa kakhulu kunazo zonke yamabhuloho esakhiwo sensimbi ezweni lami, futhi ukusebenza kwayo kubaluleke kakhulu ekusebenzeni okuphephile kwamabhuloho.Li et al. I-1 ihlole izici zensimbi engu-20MnTiB evame ukusetshenziswa ebangeni le-10.9 amandla aphezulu ebangeni lokushisa eliphakeme elingu-20~700 ℃, yaphinde yathola ijika le-stress-strain, amandla okukhiqiza, amandla aqinile, imodulus ye-Young, nobude. kanye ne-coefficient yokwandisa.Zhang et al. 2, Hu et al. 3 njll
Amabhuloho anamandla aphezulu amabhuloho ensimbi avame ukusetshenziswa isikhathi eside endaweni enomswakama.Izici ezifana nomswakama ophezulu, izinga lokushisa eliphezulu, kanye nokucwiliswa nokumuncwa kwezinto eziyingozi endaweni ezungezile kungabangela ukugqwala kwezakhiwo zensimbi.Ukugqwala kungabangela ukulahlekelwa kwe-bolt ye-cross-section, okuholela ekuqhekekeni kanye nokuqhekeka okuningi, futhi lokhu kuzoqhubeka nokuqhekeka okuningi. ukunciphisa impilo yama-bolts anamandla amakhulu ngisho nokuwabangela ukuba aphule.Kuze kube manje, kunezifundo eziningi mayelana nomphumela wokugqwala kwemvelo ekusebenzeni kokugqwala kokucindezeleka kwezinto.I-Catar et al4 iphenye ukuziphatha kokugqwala kokucindezeleka kwe-magnesium alloys enokuqukethwe okuhlukile kwe-aluminium ezindaweni ezine-asidi, i-alkaline kanye ne-neutral by slow strain corrosion rateb kanye ne-electrot straining test(SS). ukuziphatha kwe-Cu10Ni ingxubevange ku-3.5% isixazululo se-NaCl phambi kokugxila okuhlukene kwama-ion e-sulfide. U-Aghion et al.6 uhlole ukusebenza kokugqwala kwe-die-cast magnesium alloy MRI230D ku-3.5% isixazululo se-NaCl ngokucwiliswa kokuhlolwa kokucwiliswa, ukuhlolwa kwe-salt spray, i-salt spray test, i-polarization ye-polarization ye-stress analysis kanye ne-hanghang ye-stress polarization analysis.7 I-9Cr martensitic steel isebenzisa i-SSRT nezindlela zokuhlola ze-electrochemical zendabuko, yaphinde yathola umphumela wama-ion e-chloride ekuziphatheni kokugqwala okumile kwensimbi ye-martensitic ekamelweni lokushisa.U-Chen et al.8 uphenye ukuziphatha kokugqwala kwengcindezi kanye nendlela yokuqhekeka yensimbi engu-X70 esixazululweni sodaka sasolwandle esilingisiwe esiqukethe i-SRB emazingeni okushisa ahlukene e-SSRTT nomphumela wocwaningo lwe-alssRT.9 izinga lokucindezeleka emanzini olwandle ukumelana nokugqwala kwe-00Cr21Ni14Mn5Mo2N austenitic stainless steel.Imiphumela ibonisa ukuthi izinga lokushisa ebangeni elingu-35~65℃ alinawo umthelela obalulekile ekuziphatheni kokugqwala kwengcindezi kwensimbi engagqwali.Lu et al. I-10 ihlole ukuthambekela kokuphuka okubambezelekile kwamasampula anamabanga ahlukene wamandla aqinile ngomthwalo oshonile obambezelekile ukuhlolwa kokuphuka kanye ne-SSRT.Kuphakanyiswa ukuthi amandla aqinile ensimbi angu-20MnTiB kanye namabhawodi ensimbi angu-35VB anamandla aphezulu kufanele alawulwe kokuthi 1040-1190MPa 100-1190MPa l olulula ukusebenzisa lezi zifundo eziyi-3. indawo eyonakalisayo, kuyilapho indawo yangempela yokusetshenziswa kwamabholithi anamandla aphezulu iyinkimbinkimbi kakhulu futhi inezici eziningi ezithonyayo, njengenani le-pH lebhawodi.Ananya et al. I-11 ifunde umphumela wamapharamitha wemvelo nezinto zokwakha endaweni egqwalayo ekugqwaleni nasekuqhekekeni kokugqwala kwengcindezi kwama-duplex stainless steels.Sunada et al. I-12 yenze ukuhlola kokuqhekeka kwengcindezi yegumbi lokushisa kwensimbi ku-SUS304 insimbi ezixazululweni ezinamanzi eziqukethe i-H2SO4 (0-5.5 kmol/m-3) kanye ne-NaCl (0-4.5 kmol/m-3). Ukugxila kwe-CO2 / CO, ingcindezi yegesi kanye nesikhathi sokugqwala ekuthambekeni kokugqwala kwengcindezi yensimbi yensimbi ye-A516. Ukusebenzisa isisombululo se-NS4 njengesixazululo sokulingisa amanzi angaphansi komhlaba, u-Ibrahim et al. 14 yaphenya umthelela wemingcele yezemvelo njengokugxiliswa kwe-bicarbonate ion (HCO), i-pH kanye nezinga lokushisa ekuqhekekeni kokugqwala kokucindezeleka kwensimbi yepayipi ye-API-X100 ngemva kokuxebuka i-coating.Shan et al. I-15 ifunde umthetho wokuhluka we-stress corrosion cracking susceptibility of austenitic stainless steel stainless 00Cr18Ni10 ngezinga lokushisa ngaphansi kwezimo zokushisa ezihlukene (30~250℃) ngaphansi kwesimo sendawo emnyama yamanzi endaweni yokulingisa yamalahle kuya ku-hydrogen nge-SSRT. ukuhlolwa kokuphuka okubambezelekile kanye ne-SSRT.Zhao17 ifunde imiphumela ye-pH, SO42-, Cl-1 ekuziphatheni kokugqwala kwengcindezi kwe-GH4080A ingxubevange nge-SSRT. Imiphumela ibonisa ukuthi ukuncipha kwevelu ye-pH, kuba kubi kakhulu ukumelana nokugqwala kwengcindezi kwe-GH4080A ingxubevange. Ine-stress esobala ukugqwala nokuzwela kwe-isoni1 izinga lokushisa legumbi.Nokho, kukhona izifundo ezimbalwa ngomphumela wokugqwala kwemvelo kumabholithi ensimbi angu-20MnTiB anamandla aphezulu.
Ukuze kutholwe izizathu zokuhluleka kwamabholithi anamandla aphezulu asetshenziswa kumabhuloho, umbhali wenze uchungechunge lwezifundo.Amasampula ebhawodi anamandla aphezulu akhethiwe, futhi izizathu zokwehluleka kwala masampula kwaxoxwa ngazo ngokwemibono yokubunjwa kwamakhemikhali, ukuqhekeka kwe-microscopic morphology, ukwakheka kwe-metallographic kanye nokuhlaziywa kwezakhiwo zemishini19, 20 phenying eminyakeni yamuva nje yophenyo lwe-Chongqing eminyakeni yakamuva. isikimu sokugqwala esilingisa isimo sezulu esinomswakama sase-Chongqing siyaklanywa.Ukuhlolwa kokugqwala kwengcindezi, ukuhlolwa kokugqwala kwe-electrochemical kanye nokuhlolwa kokukhathala kokugqwala kwamabhothi anamandla aphezulu e-Chongqing elingisa isimo sezulu esinomswakama kwenziwa.Kulolu cwaningo, imiphumela yezinga lokushisa, inani le-pH nokugxila kokulingisa ukugqwala okulingisiwe kube yisixazululo se-stress corrosion corrosion 20M ye-stress corrosion high-20M ngokuhlolwa kwempahla eyimishini, ukuhlaziywa kwe-fracture macroscopic kanye ne-microscopic, kanye nemikhiqizo yokugqwala komhlaba.
I-Chongqing itholakala eningizimu-ntshonalanga yeChina, ezindaweni eziphakeme zoMfula i-Yangtze, futhi inesimo sezulu esishisayo se-monsoon.Isilinganiso sokushisa esimaphakathi sonyaka singu-16-18°C, umswakama ojwayelekile wonyaka ucishe ube ngu-70-80%, amahora okukhanya kwelanga waminyaka yonke angamahora angu-1000-1400, kanti amaphesenti angu-35 kuphela okukhanya kwelanga.
Ngokwemibiko ehlobene nokushisa kwelanga nezinga lokushisa le-ambient e-Chongqing kusukela ngo-2015 kuya ku-2018, izinga lokushisa elimaphakathi nsuku zonke e-Chongqing liphansi njengo-17°C futhi liphakeme ngendlela engu-23°C. Izinga lokushisa eliphakeme kakhulu emzimbeni webhuloho le-Chaotianmen Bridge e-Chongqing lingafinyelela ku-50°C °C21,22.Ngakho-ke, amazinga okushisa okuhlolwa kokugqwala kwengcindezi asethwe ku-25°C naku-50°C.
Inani le-pH lesisombululo sokugqwala esilingisiwe linquma ngokuqondile inani le-H+, kodwa alisho ukuthi uma liphansi inani le-pH, ukugqwala okulula kwenzeka.Umphumela we-pH emiphumeleni uzohluka ngezinto ezihlukene nezisombululo. Ukuze ufunde kangcono umthelela wesixazululo sokugqwala esilingisiwe ekusebenzeni kokugqwala kwengcindezi kwamabhawudo anamandla aphezulu, ukugqwala kwe-pH kuye kwaba ngu-5 wokuhlolwa kwe-5 corrosion. kanye no-7.5 kuhlanganiswe nocwaningo lwezincwadi23 kanye nebanga le-pH lamanzi emvula wonyaka e-Chongqing.2010 kuya ku-2018.
Ukuphakama kwesisombululo sokugqwala esilingisiwe, kulapho okuqukethwe kwe-ion engeziwe esixazululweni sokugqwala esilingiswayo, kanye nomthelela omkhulu ezimpahleni ezibonakalayo. Ukuze kufundwe umthelela wokugxilisa okulingiswa kokugqwala kokugqwala kokugqwala kokucindezeleka kwamabholithi anamandla amakhulu, ilabhorethri yokwenziwa yasheshisa ukugqwala kokuhlolwa kwe-corrosion, kwatholwa izinga le-corrosion, kanye nesixazululo esilinganisiwe. Ukugxila kwesixazululo sokugqwala sokuqala esilingisiwe (1×), 20 × ukugxila kwesixazululo sokugqwala kwasekuqaleni (20 ×) kanye nokugxila kwesixazululo sokugqwala esingu-200 × sangempela (200 ×).
Imvelo enezinga lokushisa elingu-25℃, inani le-pH elingu-5.5, kanye nokugxiliswa kwesisombululo sokuqala sokugqwala esilingisiwe siseduze kakhulu nezimo zangempela zokusetshenziswa zamabhawodi anamandla amakhulu amabhuloho. Nokho, ukuze kusheshiswe inqubo yokuhlola ukugqwala, izimo zokuhlola ezinezinga lokushisa elingu-25 °C, i-pH yereferensi engu-5.20 × isethi yokugxiliswa kwereferensi ka-5.5 × i-corrosion yasekuqaleni. iqembu lokulawula.Lapho imiphumela yezinga lokushisa, ukugxila noma inani le-pH lesisombululo sokugqwala esilingisiwe ekusebenzeni kokugqwala kokucindezeleka kwamabholithi anamandla aphezulu kuphenywa ngokulandelana, ezinye izici zahlala zingashintshiwe, ezisetshenziswe njengezinga lokuhlola leqembu lokulawula ireferensi.
Ngokombiko wekhwalithi yemvelo wango-2010-2018 okhishwe yi-Chongqing Municipal Bureau of Ecology and Environment, futhi ubhekisela ezingxenyeni zemvula ezibikwe e-Zhang24 nezinye izincwadi ezibikwe e-Chongqing, isixazululo sokugqwala esilingisiwe esisekelwe ekwandiseni ukugxila kwe-SO42- saklanywa. isixazululo sokugqwala esilingisiwe siboniswa kuThebula 1:
Isixazululo sokugqwala esilingisiwe silungiswa ngendlela yebhalansi ye-ion yamakhemikhali yamakhemikhali kusetshenziswa ama-reagents okuhlaziya namanzi acwecwe.Inani le-pH lesisombululo sokugqwala esilingisiwe lalungiswa ngemitha ye-pH enembile, isixazululo se-nitric acid nesisombululo se-sodium hydroxide.
Ukuze ulingise isimo sezulu esinomswakama e-Chongqing, isihloli sesifutho sikasawoti sishintshwe ngokukhethekile futhi saklanywa25.Njengoba kuboniswe kumfanekiso 1, okokusebenza kokuhlola kunezinhlelo ezimbili: isistimu yesifutho sikasawoti kanye nesistimu yokukhanyisa.Isistimu yesifutho sikasawoti iwumsebenzi oyinhloko wemishini yokuhlola, ehlanganisa ingxenye yokulawula, ingxenye yesifutho kanye nengxenye yokungeniswa. ingxenye yakhiwe ngezinto zokulinganisa izinga lokushisa, ezizwa izinga lokushisa egumbini lokuhlola.Ingxenye yokulawula yenziwe nge-microcomputer, exhuma ingxenye yesifutho kanye nengxenye yokungeniswa ukuze ilawule yonke inqubo yokuhlola.Isistimu yokukhanyisa ifakwe egumbini lokuhlola isifutho sikasawoti ukuze silingise ukukhanya kwelanga.Isistimu yokukhanyisa iqukethe izibani ze-infrared kanye nesilawuli sesikhathi.Ngaleso sikhathi isampula yenzwa yokushisa ifafazwa endaweni yokuhlola ukushisa, inzwa yokuhlola ifafaza inzwa yokushisa ekamelweni lokuhlola. isikhathi sangempela.
Amasampula okugqwala kwengcindezi ngaphansi komthwalo oqhubekayo acutshungulwa ngokuhambisana ne-NACETM0177-2005 (Ukuhlolwa Kwelabhorethri ye-Sulfide Stress Cracking and Stress Corrosion Cracking Resistance of Metals in a H2S Environment).Izibonelo ze-Stress corrosion zaqala ukuhlanzwa nge-acetone kanye ne-ultrasonic mechanical cleaning ne-ultrasonic mechanical cleaning ukuze kukhishwe uwoyela omisiwe we-anhydrated, bese ufaka i-oil denhydrated omisiwe. amasampula ahlanzekile angene ekamelweni lokuhlola ledivayisi yokuhlola isifutho sikasawoti ukulingisa isimo sokugqwala endaweni enomswakama yesimo sezulu saseChongqing.Ngokwezinga elijwayelekile le-NACETM0177-2005 kanye nokuhlolwa kwe-salt spray standard GB/T 10,125-2012, isikhathi sokuhlola ukugqwala komthwalo oqhubekayo kulolu cwaningo kunqunywa ngokulinganayo ukuthi ukuhlolwa kwe-6 kukhishwe. ngaphansi kwezimo ezihlukene zokugqwala emshinini wokuhlola oqinile we-MTS-810, kanye nezakhiwo zawo zemishini kanye ne-fracture corrosion morphology yahlaziywa.
Umfanekiso we-1 ubonisa i-macro- and micro-morphology of the surface corrosion of high-strength bolt stress corrosion specimens ngaphansi kwezimo ezihlukahlukene zokugqwala.2 kanye ne-3 ngokulandelanayo.
I-Macroscopic morphology yezibonelo zokugqwala kwengcindezi zamabhawodi wamandla aphezulu angu-20MnTiB ngaphansi kwezindawo zokugqwala ezifanisiwe ezihlukile: (a) akukho ukugqwala; (b) isikhathi esingu-1; (c) 20 ×; (d) 200 ×; (e) pH3.5; (f) pH 7.5; (g) 50°C.
I-Micromorphology yemikhiqizo yokugqwala ye-20MnTiB amabhawodi anamandla aphezulu ezindaweni ezifanisiwe zokugqwala (100×): (a) isikhathi esingu-1; (b) 20 ×; (c) 200 ×; (d) pH3.5; (e) pH7 .5; (f) 50°C.
Kungabonakala ku-Fig. 2a ukuthi ingaphezulu lesampula lebhawodi lamandla aphezulu elingagqwali libonisa ukucwebezela kwensimbi okukhanyayo ngaphandle kokugqwala okusobala.Nokho, ngaphansi kwesimo sesixazululo sokugqwala esilingisiwe sokuqala (Fig. 2b), ingaphezulu lesampula lalimbozwe ngokwengxenye nge-tan kanye ne-brown-red corrosion products, futhi ezinye izindawo zesampula ezikhanyayo zazisenezindawo ezithile ezibonisa ukuthi isampula yensimbi icwebezelayo, futhi ezinye izindawo ezisobala ze-luster zensimbi zazisabonisa ukuthi isampula yensimbi igqwalile kancane, futhi isixazululo sokugqwala esifanisiwe asizange sibe nomthelela ebusweni besampula. Izakhiwo zezinto ezibonakalayo zinomphumela omncane.Nokho, ngaphansi kwesimo sokugxiliswa kwesisombululo sokugqwala esiyi-20 × sangempela (Fig. 2c), ingaphezulu lesampula lebhawodi lamandla amakhulu limbozwe ngokuphelele inani elikhulu lemikhiqizo yokugqwala kwe-tan kanye nenani elincane lokugqwala okunsundu okubomvu.umkhiqizo, akukho ukucwebezela kwensimbi okusobala okutholakele, futhi kwakukhona isamba esincane se-substrate somkhiqizo onsundu. ngaphansi kwesimo se-200 × yasekuqaleni eyenziwe yisisombululo sokugqwala (Fig. 2d), ingaphezulu lesampula limbozwe ngokuphelele yimikhiqizo yokugqwala ensundu, kanye nemikhiqizo yokugqwala ensundu-mnyama ivela kwezinye izindawo.
Njengoba i-pH yehla yaba ngu-3.5 (Fig. 2e), imikhiqizo yokugqwala enombala onsundu yayiyiyo kakhulu ebusweni bamasampula, futhi eminye yemikhiqizo yokugqwala yayikhishiwe.
Umfanekiso 2g ubonisa ukuthi njengoba izinga lokushisa linyuka lifinyelela ku-50 °C, okuqukethwe kwemikhiqizo yokugqwala okunsundu ngokubomvu ebusweni besampula kuncipha kakhulu, kuyilapho imikhiqizo yokugqwala ensundu ngokugqamile ivala ingaphezulu lesampula endaweni enkulu.Isendlalelo somkhiqizo wokugqwala akulula, futhi eminye imikhiqizo ensundu-mnyama iyaxetshulwa.
Njengoba kuboniswe kuMdwebo 3, ngaphansi kwezindawo zokugqwala ezihlukene, imikhiqizo yokugqwala engaphezulu kuka-20MnTiB izibonelo zokugqwala kwebhawodi lamandla aphezulu ancishisiwe, futhi ukujiya kongqimba bokugqwala kuyanda ngokwanda kokugxilwa kwesisombululo sokugqwala esilingiswayo.Ngaphansi kwesimo se-corrosion yemikhiqizo eyi-3 (imikhiqizo yokugqwala eyi-3). isampula ingahlukaniswa zibe izingqimba ezimbili: ungqimba olungaphandle lwemikhiqizo yokugqwala lusakazwa ngokulinganayo, kodwa inani elikhulu lokuqhekeka livela; ungqimba lwangaphakathi luyiqoqo elixekethile lemikhiqizo yokugqwala.Ngaphansi kwesimo se-20 × sokuqala esilingisa ukugqwala kwesixazululo sokugqwala (Fig. 3b), ungqimba lokugqwala ebusweni besampula lungahlukaniswa lube izingqimba ezintathu: ungqimba olungaphandle luhlakazekile ikakhulukazi imikhiqizo yokugqwala kweqoqo, evulekile futhi enezimbotshana ezivikelayo, futhi ayinakho ukusebenza okuhle; Isendlalelo esiphakathi siwungqimba womkhiqizo ofanayo wokugqwala, kodwa kunemifantu esobala, futhi ama-ion agqwalile angadlula emifantwini futhi aqede i-substrate; ungqimba lwangaphakathi luwungqimba ominyene womkhiqizo wokugqwala ngaphandle kwemifantu esobala, enomthelela omuhle wokuvikela ku-substrate.Ngaphansi kwesimo se-200 × yasekuqaleni eyenziwe yisisombululo sokugqwala sokuhlushwa (Fig. 3c), ungqimba lokugqwala ebusweni besampula lungahlukaniswa lube yizingqimba ezintathu: ungqimba olungaphandle luyingqimba yomkhiqizo omncane futhi ofanayo; ungqimba oluphakathi luwukugqwala okumise okwe-petal futhi okumise okwe-flake Ungqimba lwangaphakathi luwungqimba oluminyene lomkhiqizo wokugqwala ngaphandle kwemifantu esobala nezimbobo, ezinomphumela omuhle wokuvikela ku-substrate.
Kungabonakala ku-Fig. 3d ukuthi endaweni yokugqwala elingisiwe ye-pH 3.5, kunenani elikhulu lemikhiqizo egqwalile entantayo noma efana nenaliti endaweni yesampula yebhawodi yamandla aphezulu engu-20MnTiB. I-corrosion layer inemifantu esobala.
Kungabonakala ku-Fig. 3f ukuthi lapho izinga lokushisa likhuphuka lifika ku-50 ° C, akukho ungqimba olucacile lokugqwala kwangaphakathi okuminyene olwatholakala esakhiweni sesendlalelo sokugqwala, okubonisa ukuthi kwakukhona izikhala phakathi kwezingqimba zokugqwala ku-50 ° C, okwenza i-substrate ingambozwa ngokuphelele imikhiqizo yokugqwala. Inikeza ukuvikeleka ekwandeni kokuthambekela kokugqwala kwe-substrate.
Izici zomshini zamabhawodi aqine kakhulu ngaphansi kokugqwala kwengcindezi yomthwalo okuqhubekayo ezindaweni ezigqwalile ezihlukene ziboniswa kuThebula 2:
Kungabonakala kuThebula lesi-2 ukuthi izici zokuwumshini zezibonelo zebhawodi enamandla amakhulu angu-20MnTiB zisahlangabezana nezimfuneko ezijwayelekile ngemva kokuhlolwa kokugqwala okusheshisiwe komjikelezo omanzi-omanzi ezindaweni ezihlukene ezilingisa ukugqwala, kodwa kunomonakalo othile uma kuqhathaniswa nalezo ezingagqwalile. isampula. I-20 × noma i-200 × ukugxila kwesisombululo esifanisiwe, ukunwetshwa kwesampula kwehle kakhulu.Izakhiwo zemishini ziyafana ekugxilweni kwe-20 × kanye ne-200 × izixazululo zangempela zokugqwala ezilingisayo.Lapho inani le-pH lesisombululo sokugqwala esilingisiwe lehla laya ku-3.5, amandla okubamba kanye nokwelula kwamasampula we-50 wehla kakhulu, lapho izinga lokushisa le-50 liyehla kakhulu, i-temperature ye-5 ° yehla kakhulu. kuncipha kakhulu, futhi izinga lokuncipha kwendawo lisondele kakhulu kunani elijwayelekile.
I-morphology yokuphuka yezibonelo zokugqwala ze-20MnTiB zamandla aphezulu we-bolt ngaphansi kwezindawo zokugqwala ezihlukene ziboniswa kuMfanekiso 4, okuyi-macro-morphology yokuphuka, indawo yefiber emaphakathi nendawo yokuphuka, udebe oluncane lwe-morphological of the shear interface, kanye nobuso besampula.
Ama-macroscopic kanye nama-microscopic fracture morphologies we-20MnTiB amasampula ebhawodi yamandla aphezulu ezindaweni ezifanisiwe zokugqwala (500×): (a) akukho ukugqwala; (b) isikhathi esingu-1; (c) 20 ×; (d) 200 ×; (e) pH3.5; (f) pH7.5; (g) 50°C.
Kungabonakala ku-Fig. 4 ukuthi ukuphuka kwesampuli ye-20MnTiB ye-bolt high-strength bolt corrosion ngaphansi kwezindawo zokugqwala ezifanisiwe ezihlukene kuveza ukuphuka kwekhoni evamile. Uma kuqhathaniswa nesampula engagqwali (Fig. 4a), indawo emaphakathi nendawo yefiber crack incane kakhulu. , indawo yezindebe ze-shear inkulu.Lokhu kubonisa ukuthi izakhiwo zemishini yezinto ezibonakalayo zonakaliswa kakhulu ngemva kokugqwala.Ngokwanda kokuhlushwa kwesisombululo sokugqwala okufanisiwe, imigodi endaweni ye-fiber ephakathi nendawo yokuphuka yanda, futhi kwavela imithungo esobala yokudabula. isampula, futhi kwakunemikhiqizo eminingi yokugqwala phezulu.isampula.
Kuthathwa kuMfanekiso 3d ukuthi kukhona ukuqhekeka okusobala kungqimba lokugqwala endaweni yesampula, engenawo umthelela omuhle wokuvikela ku-matrix. Esixazululweni sokugqwala esilingiswayo se-pH 3.5 (Umfanekiso 4e), ingaphezulu lesampula ligqwalile kakhulu, futhi indawo ye-fiber emaphakathi ngokusobala incane. , Kunenombolo enkulu yezinyembezi ezingavamile ezikhala phakathi nendawo ye-fiber.Ngokwenyuka kwenani le-pH yesisombululo sokugqwala esifanisiwe, indawo yokudabula endaweni ye-fiber ephakathi nendawo yokuphuka iyancipha, umgodi uyancipha kancane kancane, futhi ukujula komgodi nakho kuncipha kancane kancane.
Lapho izinga lokushisa lenyuka laya ku-50 ° C (Fig. 4g), indawo yodebe lwe-shear yokuphuka kwesampula yayinkulu kakhulu, imigodi esendaweni yefayibha emaphakathi yanda kakhulu, nokujula komgodi kwanda, futhi ukuxhumana phakathi konqenqema lwe-shear lip kanye nesampula yanda. Imikhiqizo yokugqwala kanye nemigodi yenyukile, okuqinisekise inkambiso ejulile yokugqwala kwe-substrate eboniswe ku-Fig. 3f.
Inani le-pH lesisombululo sokugqwala lizodala umonakalo othile ezicini zemishini zamabhawodi anamandla amakhulu angu-20MnTiB, kodwa umphumela awubalulekile.Esixazululweni sokugqwala esingu-pH 3.5, inani elikhulu lemikhiqizo yokugqwala entantayo noma efana nenaliti isakazwa ebusweni besampula, futhi ukugqwala, ungqimba olukhona olunoqhekeko olubonakalayo olunoqhekeko olusobala. imigodi ye-corrosion kanye nenani elikhulu lemikhiqizo yokugqwala ku-morphology ye-microscopic ye-fracture yesampula.Lokhu kubonisa ukuthi ikhono lesampula lokumelana nokuguquguquka ngamandla angaphandle liyancipha kakhulu endaweni ene-acidic, futhi izinga lokuthambekela kokugqwala kwengcindezi lezinto ezibonakalayo landa kakhulu.
Isixazululo sokuqala sokugqwala esilingisiwe sasinomthelela omncane ezicini zemishini zamasampula ebhawodi lamandla amakhulu, kodwa njengoba ukugxilwa kwesixazululo sokugqwala esilingisiwe kukhuphuke kwafinyelela izikhathi ezingama-20 kunesixazululo sokuqala sokugqwala esilingisiwe, izakhiwo zemishini zamasampula zonakaliswe kakhulu, futhi kwaba nokugqwala okusobala kusakhiwo se-microstructure. imigodi, imifantu yesibili kanye nemikhiqizo eminingi yokugqwala.Lapho ukugxilwa kwesisombululo sokugqwala okufanisiwe kwanda kusuka ezikhathini ezingama-20 kuya ezikhathini ezingama-200 zokugxila kwesixazululo sokugqwala kwasekuqaleni, umphumela wokugxila kwesixazululo sokugqwala kuzakhiwo zemishini yezinto ezibonakalayo waba buthaka.
Uma izinga lokushisa elilingisiwe lokugqwala lingu-25℃, amandla esivuno namandla aqinile we-20MnTiB yesampula yebhawodi yamandla aphezulu awashintshi kakhulu uma kuqhathaniswa nezifanekiso ezingagqwali. Nokho, ngaphansi kwezinga lokushisa elilingisiwe lendawo yokugqwala elingu-50 °C, amandla aqinile kanye nobude besampula behle kakhulu, inani lesampula lehla ngokuphawulekayo, izinga lokuncipha kwesilinganiso sehla ngokuphawulekayo. udebe wawumkhulu kunawo wonke, futhi kwakukhona ama-dimples endaweni ye-fiber ephakathi.Kwanda ngokuphawulekayo, ukujula komgodi kwanda, imikhiqizo yokugqwala kanye nemigodi yokugqwala yanda.Lokhu kubonisa ukuthi izinga lokushisa le-synergistic corrosion imvelo linethonya elikhulu ezintweni zemishini yamabholithi anamandla amakhulu, angabonakali ekamelweni lokushisa, kodwa okubaluleke nakakhulu lapho izinga lokushisa lifinyelela ku-50 ° C.
Ngemuva kokuhlolwa kokugqwala okusheshisiwe kwangaphakathi okulingisa indawo yomkhathi e-Chongqing, amandla aqinile, amandla okukhiqiza, ubude kanye neminye imingcele yamabhawodi anamandla amakhulu angu-20MnTiB kwehlisiwe, nomonakalo osobala wengcindezi wenzekile.Njengoba into ingaphansi kwengcindezi, kuzoba khona ukugqwala okubalulekile kwendawo ngenxa yomphumela wokugqwala ohlangene nokuhlanganiswa kwe-corrosion. emigodini, kulula ukubangela ukulimala okusobala kwepulasitiki kumabhawodi anamandla amakhulu, ukunciphisa amandla okumelana nokuguquguquka ngamandla angaphandle, futhi kwandise ukuthambekela kokugqwala kwengcindezi.
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