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Insimbi engu-20MnTiB iyinto esetshenziswa kakhulu kunazo zonke ezisetshenziswa kakhulu eziqine kakhulu 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 senza ukuhlola ukugqwala kwe-chongqing ephezulu ye-Chongqing yokuhlola ukugqwala kwesimo sezulu esishisayo. imiphumela yezinga lokushisa, inani le-pH kanye nokugxiliswa kwesisombululo sokugqwala okulingiswayo ekuziphatheni kokugqwala kokucindezeleka kwamabhawodi angu-20MnTiB anamandla aphezulu kwafundwa.
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 aqinile amabhuloho ensimbi avame ukusetshenziswa isikhathi eside endaweni enomswakama.Izici ezifana nomswakama ophezulu, izinga lokushisa eliphezulu, kanye nokuncibilika nokumuncwa kwezinto eziyingozi emvelweni kungabangela ukugqwala kwezakhiwo zensimbi.Ukugqwala kungabangela ukulahleka kwebhawodi ye-cross-section, okuholela ekuqhekekeni nasekuqhubekeni kokuqhekeka okuningi. -amandla amabhawodi ngisho nokuwabangela ukuba aphuke.Kuze kube manje, kunezifundo eziningi ngomphumela wokugqwala kwemvelo ekusebenzeni kokugqwala kokucindezeleka kwezinto.I-Catar et al4 iphenye ukuziphatha kokugqwala kwengcindezi yama-alloys e-magnesium anokuqukethwe okuhlukile kwe-aluminium ezindaweni ezine-acidic, i-alkaline kanye ne-neutral by slow strain rate testing (SSRT.) . Isixazululo se-3.5% 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 ngokuhlolwa kokucwiliswa, ukuhlolwa kwe-salt spray, ukuhlaziywa kwe-polarization ye-potentiodynamic kanye ne-SSRT.Zhangnsite yokuziphatha kwe-stress ye-stressCrr7SS ye-stressic ye-stressic et al-sss. amasu okuhlola, futhi 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 lolwandle esilingisiwe esiqukethe i-SRB emazingeni okushisa ahlukene nge-SSRT. I-1Ni14Mn5Mo2N insimbi engagqwali ye-austenitic. 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 wensimbi engu-20MnTiB kanye namabhawodi ensimbi angu-35VB anamandla aphezulu kufanele alawulwe ku-1040-1190MPa. imvelo, kuyilapho indawo yangempela yokusetshenziswa kwamabholithi anamandla aphezulu iyinkimbinkimbi futhi inezici eziningi ezithonyayo, njengenani le-pH lebhawudo.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 ukuhlolwa 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). s ingcindezi kanye nesikhathi sokugqwala ekuthambekeni kokugqwala kwengcindezi yensimbi ye-A516 yensimbi. 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.U-Han et al.16 ubonise ukulibaziseka kwesampula ye-hydrogenng susceptibility efile yokuhlolwa kwe-hydrogenng susceptibility efile yokuhlolwa okuphezulu kanye ne-SSRT.Zhao17 ifunde imiphumela ye-pH, i-SO42-, i-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.Inokuzwela okusobala kokugqwala kwengcindezi futhi ayizwelani negumbi le-Cl. umphumela wokugqwala kwemvelo kumabhawodi ensimbi angu-20MnTiB anamandla aphezulu.
Ukuze kutholwe izizathu zokuhluleka kwamabhawodi anamandla aphezulu asetshenziswa kumabhuloho, umbhali wenze uchungechunge lwezifundo.Amasampula ebhawodi anamandla aphezulu akhethiwe, futhi izizathu zokwehluleka kwalawa masampula kwaxoxwa ngazo ngokwemibono yokwakheka kwamakhemikhali, i-fracture microscopic morphology, isakhiwo se-metallographic kanye nokuhlaziywa kwezakhiwo zemishini19, i-angqingcorsion yeminyaka yakamuva yophenyo eminyakeni yakamuva ye-angqingcorsion ye-angqingcorsion. isikimu esilinganisa isimo sezulu esinomswakama sase-Chongqing siklanyelwe.Ukuhlolwa kokugqwala kwengcindezi, ukuhlola ukugqwala kwe-electrochemical kanye nokuhlolwa kokukhathala kokugqwala kwamabhawodi anamandla aphezulu e-Chongqing elingisa isimo sezulu esinomswakama kwenziwa.Kulolu cwaningo, imiphumela yezinga lokushisa, inani le-pH nokugxila kwesixazululo sokugqwala esilingisiwe ku-stress corrosion ukuziphatha kwe-stress corrosionths ngokusebenzisa i-20M-proparty corrosion ukuziphatha kwe-stress corrosion ukuziphatha kwe-stress corrosion ye-20M-mstrength-proparty ukuhlaziywa kwe-macroscopic kanye ne-microscopic, 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.Umthelela we-pH emiphumeleni uzohluka ngezinto ezihlukene nezisombululo. Ukuze ufunde kangcono umthelela wesixazululo sokugqwala esilingisiwe ekusebenzeni kokugqwala kwengcindezi kwamabhawodi anamandla aphezulu, ukugqwala kwe-pH okungu-5 kuye kwaba ngu-5 wokuhlola. kuhlanganiswe nocwaningo lwemibhalo23 kanye nebanga le-pH lamanzi emvula wonyaka e-Chongqing.2010 kuya ku-2018.
Ukuphakama kwesisombululo sokugqwala esilingisiwe, kulapho okuqukethwe kwe-ion engeziwe esixazululweni sokugqwala esilingisiwe, kanye nomthelela omkhulu ezimpahleni ezibonakalayo. Ukuze kufundwe umthelela wokugxilisa okulingiswa kokugqwala kokugqwala ekugqwaleni kokucindezeleka kwamabholithi anamandla amakhulu, ilabhorethri yokwenziwa yasheshisa ukugqwala kokuhlolwa kwe-corrosion, kwafakwa ileveli yokugqwala okulingisayo, kanye nesixazululo esifanisiwe se-corrosion. ukugxilwa kwesisombululo se-rosion (1 ×), 20 × ukugxiliswa kwesisombululo sokugqwala kwasekuqaleni (20 ×) kanye nokugxila kwesixazululo sokugqwala okungu-200 × sangempela (200 ×).
Imvelo enezinga lokushisa elingu-25℃, inani le-pH elingu-5.5, kanye nokugxiliswa kwesixazululo 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 engu-5.5 × 20 njengesixazululo sereferensi yasekuqaleni imiphumela yezinga lokushisa, ukugxila noma inani le-pH lesisombululo sokugqwala esilingisiwe ekusebenzeni kokugqwala kokucindezeleka kwama-bolts anamandla aphezulu kwaphenywa 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 kubhekiselwa ezingxenyeni zemvula ezibikwe e-Zhang24 nezinye izincwadi ezibikwe e-Chongqing, isixazululo sokugqwala esilingisiwe esisekelwe ekwandiseni ukugxila kwe-SO42- saklanywa. Ukwakheka kwe-1ngqing eyinhloko yendawo engu-2 endaweni eyi-ungqing engu-2 endaweni eyi-1 yokulingisa kwe-2 ye-Chongqing. Isixazululo se-rosion 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 sishintshiwe futhi saklanywa ngokukhethekile25.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. yezinto zokulinganisa izinga lokushisa, ezizwa izinga lokushisa ekamelweni lokuhlola.Ingxenye yokulawula yenziwe nge-microcomputer, exhuma ingxenye yesifutho kanye nengxenye yokungeniswa ukuze ilawule yonke inqubo yokuhlola.Isistimu yokukhanyisa ifakwe ekamelweni lokuhlola isifutho sikasawoti ukuze silingise ukukhanya kwelanga.Isistimu yokukhanyisa iqukethe izibani ze-infrared kanye nesilawuli sesikhathi.Ngasikhathi sinye, ukuqapha isampula senzwa yokushisa usawoti endaweni yokuhlola ukushisa kwangempela.
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 i-alcohol ehlanzekile e-hydrated bese ifaka i-oyili ehlanzekile e-hydrated. Igumbi 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 kwengcindezi yomthwalo okuqhubekayo kulolu cwaningo sinqunywa ngokufanayo ukuthi sibe yi-168 isampula ye-corrosion corrosion ngaphansi kwezimo ezihlukene ze-corrosion h. Umshini wokuhlola oqinile we-TS-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 and brown-red corrosion products, futhi ezinye izindawo ezisobala ze-luster corrosion zazibonisa ukuthi ezinye izindawo ze-luster corrosion zazibonakala ezindaweni ezithile kuphela ezibonisa ukuthi i-luster corrosion surface, futhi ezinye izindawo ezicacile ze-luster corrosion zazibonisa ukuthi ezinye izindawo ze-luster corrosion zazibonakala ezindaweni ezithile. , 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 aphezulu limbozwe ngokuphelele inani elikhulu lemikhiqizo yokugqwala kwe-tan kanye nenani elincane lokugqwala okubomvu okunsundu.umkhiqizo, akukho ukucwebezela kwensimbi okusobala okutholakele, futhi kwakukhona ngaphansi kwesimo esincane se-substrate ye-corrosion encane. I-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 izifanekiso zokugqwala kwebhawodi lamandla aphezulu zincishisiwe ngokusobala, futhi ukujiya kongqimba bokugqwala kuyanda ngokukhula kokugxila kwesisombululo sokugqwala esilingisiwe.Ngaphansi kwesimo sesampula sokugqwala kwesampula yoqobo kungahlukaniswa imikhiqizo yokugqwala3 zibe izingqimba ezimbili: ungqimba olungaphandle lwemikhiqizo yokugqwala lusakazwa ngokulinganayo, kodwa inani elikhulu lemifantu 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 luwugqinsi lomkhiqizo wokugqwala ngaphandle kokuqhekeka okusobala, okunomthelela omuhle wokuvikela ku-substrate.Ngaphansi kwesimo se-200 × yasekuqaleni eyenziwe ukugqwala kwesixazululo sokugqwala (Fig. 3c), ungqimba lokugqwala ebusweni besampula lungahlukaniswa lube yizingqimba ezintathu: ungqimba olungaphandle luwungqimba womkhiqizo 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 yokugqwala entantayo noma efana nenaliti ebusweni besampula yebhawodi yamandla aphezulu engu-20MnTiB. imifantu.
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 izakhiwo zemishini yezibonelo zamabhawodi anamandla amakhulu angu-20MnTiB zisahlangabezana nezidingo ezijwayelekile ngemva kokuhlolwa kokugqwala okusheshisiwe komjikelezo omanzi omile ezindaweni ezihlukene ezilingisa ukugqwala, kodwa kunomonakalo othile uma kuqhathaniswa nalezo ezingagqwalile. isampula. I-00× ukugxila kwesisombululo esifanisiwe, ukunwetshwa kwesampula kwehle kakhulu.Izakhiwo zomshini ziyafana ekugxilweni kwe-20 × kanye ne-200 × izixazululo zokugqwala zangempela ezilingisayo.Lapho inani le-pH lesisombululo sokugqwala esilingisiwe lehla laya ku-3.5, amandla okubamba nokunwetshwa kwamasampula kwehle kakhulu. eduze kakhulu nenani elijwayelekile.
Ama-fracture morphologies wezibonelo zokugqwala ze-20MnTiB ze-bolt high-strength 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 zonakaliswe kakhulu ngemva kokugqwala.Ngokwanda kokuhlushwa kwesixazululo sokugqwala okufanisiwe, imigodi esendaweni ye-fiber ephakathi nendawo yokuphuka yanda, futhi kwavela imithungo esobala yokudabula. kwakuyimikhiqizo eminingi egqwalile ebusweni.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 se-pH 3.5, inani elikhulu lemikhiqizo yokugqwala entantayo noma efana nenaliti isakazwa ebusweni besampula, futhi ukugqwala, ukugqwala, ungqimba olukhona olunomngcele osobala we-piste ongakwazi ukuqhekeka kahle. inani 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 kokucindezeleka kwento 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 nobude besampula behle kakhulu, inani lomlomo liye lehla ngokuphawulekayo, izinga lomlomo lehla ngokuphawulekayo, , futhi kwakukhona ama-dimples endaweni ye-fiber ephakathi.Kwanda ngokuphawulekayo, ukujula komgodi kwanda, imikhiqizo yokugqwala kanye nemigodi yokugqwala kwanda.Lokhu kubonisa ukuthi izinga lokushisa le-synergistic corrosion imvelo linethonya elikhulu emikhiqizweni yama-bolts 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 okuqinile, 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. kubangele ukulimala okusobala kwepulasitiki kumabhawodi anamandla amakhulu, kunciphise ikhono lokumelana nokuguqulwa kwamandla angaphandle, futhi kwandise ukuthambekela kokugqwala kwengcindezi.
U-Li, G., Li, M., Yin, Y. & Jiang, S. Ucwaningo lokuhlola ezimpahleni zamabhawodi aqine kakhulu enziwe ngensimbi engu-20MnTiB ezingeni lokushisa eliphakeme.jaw.Civil engineering.J.34, 100–105 (2001).
U-Hu, J., Zou, D. & Yang, Q. Ukuhlaziywa kokuhluleka kokuphuka kwensimbi engu-20MnTiB amabhawodi anamandla aphezulu ensimbi.
I-Catar, R. & Altun, H. Ukuziphatha kokugqwala kwe-stress kwama-alloys e-Mg-Al-Zn ngaphansi kwezimo ezihlukile ze-pH ngendlela ye-SSRT.Open.Chemical.17, 972–979 (2019).
Nazer, AA et al.Imiphumela ye-glycine ku-electrochemical and stress corrosion cracking behavior of Cu10Ni alloy in sulfide-contaminated brine.Industrial Engineering.Chemical.reservoir.50, 8796–8802 (2011).
I-Aghion, E. & Lulu, N. Corrosion properties of die-cast magnesium alloy MRI230D in Mg(OH)2-saturated 3.5% NaCl solution.alma mater.character.61, 1221–1226 (2010).
I-Zhang, Z., Hu, Z. & Preet, MS Ithonya lama-ion e-chloride ekuziphatheni okuqinile nokugqwala kwengcindezi kwe-9Cr martensitic steel.surf.Technology.48, 298–304 (2019).
I-Chen, X., Ma, J., Li, X., Wu, M. & Song, B. Umphumela we-Synergistic we-SRB nezinga lokushisa ekuqhekekeni kokugqwala kwengcindezi kwensimbi engu-X70 kusixazululo sodaka lolwandle lokwenziwa.I-Chin.Socialist Party.coros.Pro.39, 477–484 (2019).
U-Liu, J., Zhang, Y. & Yang, S. S. Stress corrosion behaviour of 00Cr21Ni14Mn5Mo2N insimbi engagqwali emanzini olwandle.physics.thatha i-exam.test.36, 1-5 (2018).
Lu, C. Ucwaningo olubambezelekile lokuphuka kwebhuloho lamandla aphezulu.jaw.Academic school.rail.science.2, 10369 (2019).
Ananya, B. Stress corrosion cracking of duplex stainless steels in caustic solutions.Doctoral Dissertation, Atlanta, GA, USA: Georgia Institute of Technology 137–8 (2008)
I-Sunada, S., Masanori, K., Kazuhiko, M. & Sugimoto, K. Imiphumela ye-H2SO4 nokugxila kwe-naci ekuqhekekeni kokugqwala kwengcindezi kwe-SUS304 insimbi engagqwali ku-H2SO4-NaCl aqueous solution.alma mater.trans.47, 364–370 (2006).
I-Merwe, i-JWVD Ithonya lemvelo nezinto zokwakha ekuqhekekeni kokugqwala kwensimbi kusixazululo se-H2O/CO/CO2.Inter Milan.J.Koros.2012, 1-13 (2012).
U-Ibrahim, M. & Akram A. Imithelela ye-bicarbonate, izinga lokushisa ne-pH ekudlulisweni kwensimbi yepayipi ye-API-X100 kusixazululo samanzi angaphansi komhlaba esifanisiwe.Ku-IPC 2014-33180.
U-Shan, G., Chi, L., Song, X., Huang, X. & Qu, D. Umphumela wezinga lokushisa ekuthambekeni kokuqhekeka kokugqwala kwe-austenitic stainless steel.coro.be against.Technology.18, 42–44 (2018).
U-Han, S. Ukuziphatha okubambezeleke kwe-Hydrogen okulibaziseka kwezinsimbi ezimbalwa eziqinisa amandla aphezulu (Kunming University of Science and Technology, 2014).
Zhao, B., Zhang, Q. & Zhang, M. Stress corrosion mechanism ye-GH4080A alloy for fasteners.cross.companion.Hey.treat.41, 102–110 (2020).