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Intsimbi ye-20MnTiB yeyona nto isetyenziswa kakhulu kwi-bolt enamandla aphezulu kwiibhulorho zesakhiwo sentsimbi kwilizwe lam, kwaye ukusebenza kwayo kubaluleke kakhulu ekusebenzeni ngokukhuselekileyo kweebhulorho. Ngokusekelwe kuphando lwendalo esingqongileyo eChongqing, olu phononongo luyile isisombululo sokugqwala esilinganisa imozulu efumileyo yaseChongqing, kwaye lwenze uvavanyo lokugqwala koxinzelelo lwee-bolts ezinamandla aphezulu ezilinganisa imozulu efumileyo yaseChongqing. Iziphumo zobushushu, ixabiso le-pH kunye noxinzelelo lwesisombululo sokugqwala olulinganisiweyo kwindlela yokuziphatha kokugqwala koxinzelelo lwee-bolts ezinamandla aphezulu ze-20MnTiB zifundwe.
Intsimbi ye-20MnTiB yeyona nto isetyenziswa kakhulu kwi-bolt enamandla aphezulu kwiibhulorho zesakhiwo sentsimbi kwilizwe lam, kwaye ukusebenza kwayo kubaluleke kakhulu ekusebenzeni ngokukhuselekileyo kweebhulorho. ULi et al. 1 uvavanye iipropati zentsimbi ye-20MnTiB ezisetyenziswa rhoqo kwiibholithi ezinamandla aphezulu zebanga le-10.9 kuluhlu lobushushu obuphezulu be-20 ~ 700 ℃, kwaye wafumana i-stress-strain curve, yield strength, tensile strength, Young's modulus, kunye ne-elongation. kunye ne-expansion coefficient. UZhang et al. 2, Hu et al. 3, njl., ngovavanyo lwe-chemical composition, uvavanyo lwe-mechanical property, uvavanyo lwe-microstructure, uhlalutyo lwe-macroscopic kunye ne-microscopic yomphezulu wentambo, kwaye iziphumo zibonisa ukuba isizathu esiphambili sokuqhekeka kweebholithi ezinamandla aphezulu sinxulumene neziphene zentambo, kwaye ukuvela kweziphene zentambo Uxinzelelo olukhulu, uxinzelelo oluphezulu, uxinzelelo lwe-crack tip kunye neemeko zokugqwala emoyeni ovulekileyo zonke zikhokelela ekuqhekekeni koxinzelelo.
Iibholiti ezinamandla aphezulu kwiibhulorho zentsimbi zihlala zisetyenziswa ixesha elide kwindawo enomswakama. Izinto ezinje ngokufuma okuphezulu, ubushushu obuphezulu, kunye nokutsalwa kwenkunkuma kunye nokufunxwa kwezinto ezinobungozi kwindawo zinokubangela ukubola kwezakhiwo zentsimbi ngokulula. Ukubola kunokubangela ukulahleka kwebholiti enamandla aphezulu, okubangela iziphene ezininzi kunye nokuqhekeka. Kwaye ezi ziphene kunye nokuqhekeka ziya kuqhubeka nokukhula, ngaloo ndlela kunciphisa ubomi beebholiti ezinamandla aphezulu kwaye zide zibangele ukuba ziqhekeke. Okwangoku, kukho izifundo ezininzi malunga nefuthe lokubola kwendalo ekusebenzeni kokubola koxinzelelo lwezinto. UCatar et al4 baphande ukuziphatha kokubola koxinzelelo lwee-magnesium alloys ezinomxholo owahlukileyo we-aluminium kwiindawo ezine-acidic, alkaline kunye ne-neutral ngovavanyo lwesantya esicothayo (SSRT). UAbdel et al.5 bafunde ukuziphatha kokuqhekeka koxinzelelo lwe-electrochemical kunye noxinzelelo lwe-Cu10Ni alloy kwisisombululo se-3.5% NaCl phambi koxinzelelo olwahlukeneyo lwee-ion ze-sulfide. UAghion et al.6 bavavanye ukusebenza kokubola kwe-die-cast magnesium alloy MRI230D kwisisombululo se-3.5% NaCl ngovavanyo lokuntywiliselwa, uvavanyo lwe-salt spray, uhlalutyo lwe-potentiodynamic polarization kunye I-SSRT.Zhang et al.7 bafunde indlela yokuziphatha kokugqwala koxinzelelo lwentsimbi ye-9Cr martensitic besebenzisa i-SSRT kunye neendlela zovavanyo lwe-electrochemical zemveli, baza bafumana impembelelo yee-ion ze-chloride kwindlela yokuziphatha kokugqwala okungashukumiyo kwentsimbi ye-martensitic kubushushu begumbi. UChen et al.8 baphande indlela yokuziphatha kokugqwala koxinzelelo kunye nendlela yokuqhekeka kwentsimbi ye-X70 kwisisombululo sodaka lolwandle esilingisiweyo esine-SRB kubushushu obahlukeneyo yi-SSRT. ULiu et al.9 basebenzise i-SSRT ukufunda impembelelo yobushushu kunye nesantya sokuxinana kokuxinana kokuxinana kwamanzi olwandle kwintsimbi engashukumiyo ye-00Cr21Ni14Mn5Mo2N austenitic stainless steel. Iziphumo zibonisa ukuba ubushushu obuphakathi kwe-35~65℃ abunampembelelo ibalulekileyo kwindlela yokuziphatha kokugqwala koxinzelelo lwentsimbi engashukumiyo. ULu et al. I-10 ivavanye ukuthambekela kokuqhekeka okulibazisekileyo kweesampuli ezinamazinga ahlukeneyo okutsalwa ngovavanyo lokutsalwa okulibazisekileyo komthwalo ofileyo kunye ne-SSRT. Kucetyiswa ukuba amandla okutsalwa kwentsimbi ye-20MnTiB kunye neebholiti ezinamandla aphezulu zentsimbi ye-35VB kufuneka alawulwe kwi-1040-1190MPa. Nangona kunjalo, uninzi lwezi zifundo ngokusisiseko zisebenzisa isisombululo esilula se-3.5% NaCl ukulinganisa imeko-bume eyonzakalisayo, ngelixa imeko-bume yokusetyenziswa kwebholiti ezinamandla aphezulu iyinkimbinkimbi ngakumbi kwaye inezinto ezininzi ezinefuthe, njengexabiso le-pH lebholiti. U-Ananya et al. 11 bafunde impembelelo yeparameters zokusingqongileyo kunye nezinto kwi-medium eyonzakalisayo kwi-corrosion kunye ne-stress corrosion cracking yeentsimbi ezi-stainless duplex. USunada et al. I-12 yenze uvavanyo lokuqhekeka koxinzelelo lobushushu begumbi kwintsimbi ye-SUS304 kwizisombululo zamanzi eziqulethe i-H2SO4 (0-5.5 kmol/m-3) kunye ne-NaCl (0-4.5 kmol/m-3). Iziphumo ze-H2SO4 kunye ne-NaCl kwiintlobo zokuqhekeka kwentsimbi ye-SUS304 nazo zifundwe. UMerwe et al.13 basebenzise i-SSRT ukufunda iziphumo zecala lokuqengqeleka, ubushushu, uxinzelelo lwe-CO2/CO, uxinzelelo lwegesi kunye nexesha lokuqhekeka kokuchaphazeleka kokuqhekeka koxinzelelo kwentsimbi yesitya soxinzelelo lwe-A516. Besebenzisa isisombululo se-NS4 njengesisombululo sokulinganisa amanzi angaphantsi komhlaba, u-Ibrahim et al. 14 baphande impembelelo yeparameters zokusingqongileyo ezifana noxinzelelo lwe-bicarbonate ion (HCO), i-pH kunye nobushushu ekuqhekekeni kokuqhekeka koxinzelelo kwentsimbi yepayipi ye-API-X100 emva kokukhupha i-coating. UShan et al. I-15 ifunde umthetho wokwahluka kokuqhekeka koxinzelelo lokuqhekeka kwentsimbi engagqwaliyo ye-austenitic 00Cr18Ni10 enobushushu phantsi kweemeko ezahlukeneyo zobushushu (30~250℃) phantsi kwemeko yesixhobo samanzi amnyama kwisityalo esilingisiweyo samalahle ukuya kwi-hydrogen yi-SSRT. UHan et al.16 bachaze ukuqhekeka kwe-hydrogen kwiisampuli ze-bolt ezinamandla aphezulu besebenzisa uvavanyo lokuqhekeka olulibazisekileyo lomthwalo kwaye i-SSRT. UZhao17 uhlolisise iziphumo ze-pH, SO42-, Cl-1 kwindlela yokuziphatha kokuqhekeka koxinzelelo lwe-GH4080A alloy yi-SSRT. Iziphumo zibonisa ukuba ixabiso le-pH liphantsi, kokukhona ukuxhathisa kokuqhekeka koxinzelelo lwe-GH4080A alloy kuba kubi. Inobuthathaka obucacileyo bokuqhekeka koxinzelelo kwi-Cl-1, kwaye ayivakaleli kwi-SO42-ionic medium kubushushu begumbi. Nangona kunjalo, zimbalwa izifundo malunga nesiphumo sokuqhekeka kwendalo kwiibholiti ezinamandla aphezulu zentsimbi ye-20MnTiB.
Ukuze kufunyanwe izizathu zokungaphumeleli kweebholiti ezinamandla aphezulu ezisetyenziswa kwiibhulorho, umbhali wenze uthotho lwezifundo. Kukhethwe iisampuli zeebholiti ezinamandla aphezulu, kwaye izizathu zokungaphumeleli kwezi sampuli zixoxwe ngokwembono yokwakheka kweekhemikhali, imo yemicroscopic yokuqhekeka, isakhiwo se-metallographic kunye nohlalutyo lweepropathi zoomatshini19, 20. Ngokusekelwe kuphando lwendalo esingqongileyo eChongqing kwiminyaka yakutshanje, kuyilwe inkqubo yokugqwala efana nemozulu efumileyo yaseChongqing. Uvavanyo lokugqwala koxinzelelo, uvavanyo lokugqwala kwe-electrochemical kunye novavanyo lokudinwa kokugqwala kweebholiti ezinamandla aphezulu eChongqing olulinganisiweyo lwemozulu efumileyo. Kolu phononongo, iziphumo zobushushu, ixabiso le-pH kunye noxinzelelo lwesisombululo sokugqwala esilinganisiweyo kwindlela yokuziphatha kokugqwala koxinzelelo lweebholiti ezinamandla aphezulu ze-20MnTiB ziphandwe ngovavanyo lwepropathi yoomatshini, uhlalutyo lwe-macroscopic kunye ne-microscopic yokugqwala, kunye neemveliso zokugqwala komphezulu.
IChongqing ikumzantsi-ntshona weTshayina, iindawo eziphezulu zoMlambo iYangtze, kwaye inemozulu efumileyo yemvula engaphantsi kwetropiki. Ubushushu obuqhelekileyo bonyaka yi-16-18°C, ubushushu obuqhelekileyo bonyaka buyi-70-80%, iiyure zokukhanya kwelanga zonyaka ziyi-1000-1400 iiyure, kwaye ipesenti yokukhanya kwelanga yi-25-35% kuphela.
Ngokweengxelo ezinxulumene nokukhanya kwelanga kunye nobushushu obuphakathi eChongqing ukususela ngo-2015 ukuya ku-2018, ubushushu obuqhelekileyo bemihla ngemihla eChongqing buphantsi njenge-17°C kwaye buphezulu njenge-23°C. Ubushushu obuphezulu emzimbeni webhulorho yeChaotianmen Bridge eChongqing bunokufikelela kwi-50°C °C21,22. Ke ngoko, amanqanaba obushushu ovavanyo lokugqwala koxinzelelo abekwe kwi-25°C kunye ne-50°C.
Ixabiso le-pH yesisombululo sokugqwala esilinganisiweyo limisela ngokuthe ngqo ubungakanani be-H+, kodwa oko akuthethi ukuba xa ixabiso le-pH liphantsi, kokukhona ukugqwala kulula. Isiphumo se-pH kwiziphumo siya kwahluka kwizixhobo ezahlukeneyo kunye nezisombululo. Ukuze kufundwe ngcono isiphumo sesisombululo sokugqwala esilinganisiweyo ekusebenzeni kokugqwala koxinzelelo lweebholiti ezinamandla aphezulu, amaxabiso e-pH ovavanyo lokugqwala koxinzelelo abekwe kwi-3.5, 5.5 kunye ne-7.5 ngokudibeneyo nophando loncwadi23 kunye noluhlu lwe-pH lwamanzi emvula ngonyaka eChongqing.2010 ukuya ku-2018.
Okukhona uxinzelelo lwesisombululo sokugqwala esilinganisiweyo luphezulu, kokukhona umxholo we-ion kwisisombululo sokugqwala esilinganisiweyo uphezulu, kwaye kokukhona impembelelo enkulu kwiimpawu zezinto. Ukuze kufundwe isiphumo soxinzelelo lwesisombululo sokugqwala esilinganisiweyo kwi-stress corrosion ye-high-strength bolts, uvavanyo lokugqwala olukhawulezileyo lwelebhu yokwenziwa luye lwafezekiswa, kwaye uxinzelelo lwesisombululo sokugqwala olulinganisiweyo lubekwe kwinqanaba lesi-4 ngaphandle kokugqwala, ezaziluxinzelelo lwesisombululo sokugqwala olulinganisiweyo lokuqala (1×), uxinzelelo lwesisombululo sokugqwala olulinganisiweyo lokuqala (20 ×) kunye noxinzelelo lwesisombululo sokugqwala olulinganisiweyo lokuqala (200 ×).
Indawo enobushushu obuyi-25℃, ixabiso le-pH eliyi-5.5, kunye noxinzelelo lwesisombululo sokuqala sokugqwala esilinganisiweyo yeyona ikufutshane neemeko zokusetyenziswa kweebholiti ezinamandla aphezulu kwiibhulorho. Nangona kunjalo, ukuze kukhawuleziswe inkqubo yovavanyo lokugqwala, iimeko zovavanyo ezinobushushu obuyi-25 °C, i-pH eyi-5.5 kunye noxinzelelo lwesisombululo sokugqwala esilinganisiweyo esiyi-200 × sokuqala zamiselwa njengeqela lolawulo lwesalathiso. Xa iziphumo zobushushu, uxinzelelo okanye ixabiso le-pH yesisombululo sokugqwala esilinganisiweyo ekusebenzeni kokugqwala koxinzelelo lweebholiti ezinamandla aphezulu ziphandwe ngokwahlukeneyo, ezinye izinto azizange zitshintshe, ezasetyenziswa njengenqanaba lovavanyo leqela lolawulo lwesalathiso.
Ngokwengxelo yomgangatho wokusingqongileyo komoya ka-2010-2018 ekhutshwe yiChongqing Municipal Bureau of Ecology and Environment, kwaye ibhekisa kwizinto ezibangela ukuna kwemvula ezixelwe kwiZhang24 kunye nezinye iincwadi ezixelwe kwiChongqing, isisombululo sokuna kwemvula esisekelwe ekwandiseni uxinzelelo lwe-SO42- sayilwa. Ukwakheka kwemvula kwindawo ephambili yedolophu yaseChongqing ngo-2017. Ukwakheka kwesisombululo sokuna kwemvula esixelwe kuboniswe kwiTheyibhile 1:
Isisombululo sokugqwala esilinganiswayo silungiswa ngendlela yokulinganisela i-ion yekhemikhali kusetyenziswa ii-reagents zohlalutyo kunye namanzi acociweyo. Ixabiso le-pH yesisombululo sokugqwala esilinganiswayo silungisiwe ngemitha ye-pH echanekileyo, isisombululo se-nitric acid kunye nesisombululo se-sodium hydroxide.
Ukuze kulinganiswe imozulu efumileyo eChongqing, umvavanyi we-salt spray uguqulwe ngokukodwa kwaye wenzelwe25. Njengoko kubonisiwe kuMfanekiso 1, izixhobo zovavanyo zineenkqubo ezimbini: inkqubo ye-salt spray kunye nenkqubo yokukhanyisa. Inkqubo ye-salt spray ngumsebenzi ophambili wezixhobo zovavanyo, equlathe inxalenye yokulawula, inxalenye ye-spray kunye nenxalenye ye-induction. Umsebenzi wenxalenye ye-spray kukupompa inkungu yetyuwa kwigumbi lovavanyo nge-air compressor. Icandelo le-induction lenziwe ngezinto zokulinganisa ubushushu, eziqonda ubushushu kwigumbi lovavanyo. Icandelo lolawulo lenziwe yi-microcomputer, edibanisa inxalenye ye-spray kunye nenxalenye ye-induction ukulawula yonke inkqubo yovavanyo. Inkqubo yokukhanyisa ifakwe kwigumbi lovavanyo lwe-salt spray ukulinganisa ukukhanya kwelanga. Inkqubo yokukhanyisa inezibane ze-infrared kunye ne-time controller. Kwangaxeshanye, kufakwa i-sensor yobushushu kwigumbi lovavanyo lwe-salt spray ukujonga ubushushu obujikeleze isampuli ngexesha langempela.
Iisampulu zokugqwala koxinzelelo phantsi komthwalo ongaguqukiyo zicutshungulwe ngokuhambelana ne-NACETM0177-2005 (Uvavanyo lweLabhoratri lokuGqwala koxinzelelo lweSulfide kunye nokuxhathisa ukugqwala koxinzelelo lweMetals kwindawo ye-H2S). Iisampulu zokugqwala koxinzelelo zaqala zacocwa nge-acetone kunye nokucoca ngoomatshini be-ultrasonic ukususa iintsalela zeoyile, emva koko zacinywa ngotywala zaza zomiswa kwi-oven. Emva koko faka iisampulu ezicocekileyo kwigumbi lovavanyo lwesixhobo sovavanyo lokutshiza ityuwa ukuze kulinganiswe imeko yokugqwala kwindawo yemozulu efumileyo yaseChongqing. Ngokwe-NACETM0177-2005 esemgangathweni kunye nomgangatho wovavanyo lokutshiza ityuwa i-GB/T 10,125-2012, ixesha lovavanyo lokugqwala koxinzelelo lomthwalo ongaguqukiyo kolu phononongo limiselwe ngokulinganayo ukuba ziiyure ezili-168. Uvavanyo lokuxinana lwenziwa kwiisampulu zokugqwala phantsi kweemeko ezahlukeneyo zokugqwala kumatshini wovavanyo lokuxinana we-MTS-810 jikelele, kwaye iimpawu zazo zoomatshini kunye nemo ye-corrosion corrosion zahlalutywa.
Umfanekiso 1 ubonisa i-macro- kunye ne-micro-morphology yokubola komphezulu weesampuli zokubola kwe-bolt stress stress ephezulu phantsi kweemeko ezahlukeneyo zokubola.2 kunye no-3 ngokulandelanayo.
Imo ye-macroscopic yeesampuli zokugqwala koxinzelelo lweebholiti ezinamandla aphezulu ze-20MnTiB phantsi kweemeko ezahlukeneyo zokugqwala ezilinganisiweyo: (a) akukho ukugqwala; (b) ixesha eli-1; (c) 20 ×; (d) 200 ×; (e) pH3.5; (f) pH 7.5; (g) 50°C.
I-Micromorphology yeemveliso zokugqwala kweebholiti ezinamandla aphezulu ze-20MnTiB kwiindawo ezahlukeneyo zokugqwala ezilinganisiweyo (100×): (a) ixesha eli-1; (b) 20 ×; (c) 200 ×; (d) pH3.5; (e) pH7 .5; (f) 50°C.
Kuyabonakala kwiFig. 2a ukuba umphezulu wesampuli yebholti engagqwaliyo ibonakalisa ukukhanya kwesinyithi okukhanyayo ngaphandle kokugqwala okubonakalayo. Nangona kunjalo, phantsi kwesimo sesisombululo sokuqala sokugqwala esilinganisiweyo (Fig. 2b), umphezulu wesampuli wawugqunywe kancinci ngeemveliso zokugqwala ezimnyama nezibomvu-mdaka, kwaye ezinye iindawo zomphezulu zisabonisa ukukhanya kwesinyithi okubonakalayo, okubonisa ukuba ziindawo ezithile zomphezulu wesampuli ezigqwalisiweyo kancinci, kwaye isisombululo sokugqwala esilinganisiweyo asinampembelelo kumphezulu wesampuli. Iimpawu zezinto azinampembelelo ingako. Nangona kunjalo, phantsi kwemeko yoxinzelelo lwesisombululo sokugqwala oluyi-20 × yokuqala (Umzobo 2c), umphezulu wesampuli yebholiti enamandla aphezulu ugqunywe ngokupheleleyo yimveliso enkulu yokugqwala okumnyama kunye nemveliso encinci yokugqwala okumdaka-bomvu. Akukho lukhazimlo lwesinyithi olucacileyo olufunyenweyo, kwaye kwakukho imveliso encinci yokugqwala okumdaka-mnyama kufutshane nomphezulu wesiseko. Kwaye phantsi kwemeko yoxinzelelo lwesisombululo sokugqwala oluyi-200 × yokuqala (Umzobo 2d), umphezulu wesampuli ugqunywe ngokupheleleyo yimveliso yokugqwala okumdaka, kwaye iimveliso zokugqwala ezimdaka-mnyama ziyavela kwezinye iindawo.
Njengoko i-pH yehla yaya kwi-3.5 (Umz. 2e), iimveliso zokugqwala ezinombala onsundu zazizezona ziphezulu kwiisampuli, kwaye ezinye zeemveliso zokugqwala zazikhutshiwe.
Umfanekiso 2g ubonisa ukuba njengoko ubushushu bunyuka bufikelela kwi-50 °C, umxholo weemveliso zokugqwala ezimdaka-bomvu kumphezulu wesampuli uyancipha kakhulu, ngelixa iimveliso zokugqwala ezimdaka-mhlophe zigubungela umphezulu wesampuli kwindawo enkulu. Umaleko wemveliso yokugqwala ukhululekile, kwaye ezinye iimveliso ezimdaka-mnyama ziyaxotyulwa.
Njengoko kubonisiwe kuMfanekiso 3, phantsi kweemeko ezahlukeneyo zokugqwala, iimveliso zokugqwala kumphezulu weesampuli zokugqwala ze-20MnTiB ezinamandla aphezulu zicacile ukuba ziqhekekile, kwaye ubukhulu bomaleko wokugqwala buyanda ngokwanda koxinzelelo lwesisombululo sokugqwala esilinganisiweyo. Phantsi kwemeko yesisombululo sokugqwala esilinganisiweyo sokuqala (Umfanekiso 3a), iimveliso zokugqwala kumphezulu wesampuli zinokwahlulwa zibe ziileya ezimbini: umaleko ongaphandle weemveliso zokugqwala usasazwe ngokulinganayo, kodwa kuvela inani elikhulu leemifantu; umaleko ongaphakathi yiqela elikhululekileyo leemveliso zokugqwala. Phantsi kwemeko yoxinzelelo lwesisombululo sokugqwala esilinganisiweyo sokuqala se-20× (Umfanekiso 3b), umaleko wokugqwala kumphezulu wesampuli unokwahlulwa ube ziileya ezintathu: umaleko ongaphandle ikakhulu ziimveliso zokugqwala zeqela ezisasazekileyo, ezikhululekileyo nezingenamibhobho, kwaye azinawo umsebenzi olungileyo wokukhusela; Umaleko ophakathi ngumaleko wemveliso yokugqwala ofanayo, kodwa kukho iimifantu ezicacileyo, kwaye ii-ion zokugqwala zinokudlula kwiimfantu kwaye zitshabalalise isiseko; umaleko wangaphakathi ngumaleko wemveliso yokubola oxineneyo ongenazimfa ezicacileyo, onefuthe elihle lokukhusela kwisiseko. Phantsi kwemeko yoxinzelelo lwesisombululo sokubola olulinganisiweyo lwe-200× (Umzobo 3c), umaleko wokubola kumphezulu wesampuli unokwahlulwa ube ziimfa ezithathu: umaleko wangaphandle ngumaleko wemveliso yokubola obhityileyo nofanayo; umaleko ophakathi ngokuyintloko ungowokubola okwimo yepetali nowokubola okwimo yefleyiti. Umaleko wangaphakathi ngumaleko wemveliso yokubola oxineneyo ongenazimfa ezicacileyo kunye nemingxunya, onefuthe elihle lokukhusela kwisiseko.
Kuyabonakala kwiFig. 3d ukuba kwindawo yokugqwala eyenziweyo ye-pH 3.5, kukho inani elikhulu leemveliso zokugqwala ezifana ne-flocculent okanye inaliti kumphezulu wesampuli ye-bolt enamandla aphezulu ye-20MnTiB. Kucingelwa ukuba ezi mveliso zokugqwala ikakhulu yi-γ-FeOOH kunye nenani elincinci le-α-FeOOH elidityanisiweyo26, kwaye umaleko wokugqwala unezikhewu ezicacileyo.
Kuyabonakala kwiFig. 3f ukuba xa ubushushu bunyukela kwi-50 °C, akukho maleko wokugqwala ocacileyo ongaphakathi ofunyenweyo kwisakhiwo semaleko yokugqwala, nto leyo ebonisa ukuba bekukho izikhewu phakathi kwamaleko okugqwala kwi-50 °C, nto leyo eyenza ukuba i-substrate ingagqunywanga ngokupheleleyo ziimveliso zokugqwala. Ibonelela ngokhuseleko ekuthambekeleni kokugqwala kwe-substrate.
Iimpawu zoomatshini zeebholiti ezinamandla aphezulu phantsi kokugqwala koxinzelelo lomthwalo oluqhubekayo kwiindawo ezahlukeneyo zokugqwala ziboniswe kwiTheyibhile 2:
Kuyabonakala kwiTheyibhile 2 ukuba iipropati zoomatshini zeesampuli ze-20MnTiB ezinamandla aphezulu zisahlangabezana neemfuno ezisemgangathweni emva kokuba umjikelo owomileyo ukhawulezise uvavanyo lokugqwala kwiindawo ezahlukeneyo zokugqwala ezilinganisiweyo, kodwa kukho umonakalo othile xa kuthelekiswa nezo zingagqwalanga. Kwingxinano yesisombululo sokuqala sokugqwala esilinganisiweyo, iipropati zoomatshini zesampuli azitshintshanga kakhulu, kodwa kwingxinano ye-20× okanye ye-200× yesisombululo esilinganisiweyo, ukwandiswa kwesampuli kwehla kakhulu. Iipropati zoomatshini ziyafana kwingxinano yezisombululo zokuqala zokugqwala ezilinganisiweyo ze-20 × kunye ne-200 ×. Xa ixabiso le-pH yesisombululo sokugqwala esilinganisiweyo lehla ukuya kwi-3.5, amandla okutsalwa kunye nokwandiswa kweesampuli kwehla kakhulu. Xa ubushushu bunyuka ukuya kwi-50°C, amandla okutsalwa kunye nokwandiswa kwehla kakhulu, kwaye izinga lokuncitshiswa kwendawo lisondele kakhulu kwixabiso eliqhelekileyo.
Iimofologiya zokuqhekeka kweesampuli zokuqhekeka kwe-20MnTiB high-strength bolt stress corrosion phantsi kweemeko ezahlukeneyo zokuqhekeka ziboniswe kuMfanekiso 4, eziyimofologiya ye-fracture, indawo yefayibha embindini we-fracture, i-micro-morphological lip ye-shear interface, kunye nomphezulu wesampuli.
Iimofologies ze-macroscopic kunye ne-microscopic fracture ze-20MnTiB high-strength bolt specimens kwiindawo ezahlukeneyo ze-corrosion ezilinganisiweyo (500×): (a) akukho corrosion; (b) ixesha eli-1; (c) 20 ×; (d) 200 ×; (e) pH3.5; (f) pH7.5; (g) 50°C.
Kuyabonakala kwiFig. 4 ukuba ukwaphuka kwesampuli ye-20MnTiB yoxinzelelo lwe-corrosion stress phantsi kweemeko ezahlukeneyo ze-corrosion ezilinganisiweyo kubonisa ukwaphuka okuqhelekileyo kwe-cup-cone. Xa kuthelekiswa nesampuli engagqwaliyo (Fig. 4a), indawo ephakathi yendawo yefayibha incinci kakhulu. , indawo ye-shear lip inkulu. Oku kubonisa ukuba iipropati zoomatshini zezinto zonakaliswe kakhulu emva kokugqwala. Ngokwanda koxinzelelo lwesisombululo se-corrosion esilinganisiweyo, imingxuma kwindawo yefayibha embindini we-fracture yanda, kwaye kwavela imithungo yokukrazula ecacileyo. Xa uxinzelelo lwanda ukuya kuthi ga kwi-20 yesisombululo se-corrosion esilinganisiweyo sokuqala, imingxuma ye-corrosion ecacileyo yavela kwindawo ephakathi komphetho we-shear lip kunye nomphezulu wesampuli, kwaye kwakukho iimveliso ezininzi ze-corrosion kumphezulu.
Kucingelwa ukuba kuMfanekiso 3d kukho iintanda ezicacileyo kumaleko wokugqwala kumphezulu wesampuli, ezingenampembelelo ilungileyo yokukhusela kwi-matrix. Kwisisombululo sokugqwala esilinganisiweyo se-pH 3.5 (Umfanekiso 4e), umphezulu wesampuli ugqwala kakhulu, kwaye indawo yefayibha ephakathi ngokucacileyo incinci. , Kukho inani elikhulu leemithungo zokukrazula ezingalinganiyo embindini wendawo yefayibha. Ngokunyuka kwexabiso le-pH yesisombululo sokugqwala esilinganisiweyo, indawo yokukrazula kwindawo yefayibha embindini wokuqhekeka iyancipha, umngxuma uyancipha kancinci kancinci, kwaye ubunzulu bomngxuma nabo buyehla kancinci kancinci.
Xa ubushushu bunyukela kwi-50 °C (Umzobo 4g), indawo yomlomo otyumkileyo apho kwaqhekeka khona isampuli yayiyeyona inkulu, imingxunya kwindawo ephakathi yefayibha yanda kakhulu, kwaye ubunzulu bomgodi nabo banda, kwaye unxibelelwano phakathi komphetho womlomo otyumkileyo kunye nomphezulu wesampuli lwanda. Iimveliso zomhlwa kunye nemingxunya zanda, nto leyo eqinisekisile ukutyekela kokubola kwe-substrate okubonakaliswe kuMfanekiso 3f.
Ixabiso le-pH yesisombululo sokugqwala liza kubangela umonakalo othile kwiimpawu zoomatshini ze-20MnTiB high-strength bolts, kodwa isiphumo asibalulekanga. Kwisisombululo sokugqwala se-pH 3.5, inani elikhulu leemveliso zokugqwala ezifana ne-flocculent okanye inaliti zisasazwa kumphezulu wesampuli, kwaye umaleko wokugqwala unemifantu ecacileyo, engenakwenza ukhuseleko olufanelekileyo lwe-substrate. Kwaye kukho imingxunya yokugqwala ecacileyo kunye nenani elikhulu leemveliso zokugqwala kwi-microscopic morphology yokuqhekeka kwesampuli. Oku kubonisa ukuba amandla esampuli okumelana nokuguqulwa ngamandla angaphandle ancitshisiwe kakhulu kwindawo ene-asidi, kwaye inqanaba lokugqwala koxinzelelo lwezinto liyanda kakhulu.
Isisombululo sokuqala sokugqwala esilinganisiweyo besingenampembelelo ingako kwiimpawu zoomatshini zeesampuli zebholiti ezinamandla aphezulu, kodwa njengoko uxinzelelo lwesisombululo sokugqwala esilinganisiweyo lunyuke lwaya kutsho kuma-20 amaxesha kunesisombululo sokuqala sokugqwala esilinganisiweyo, iimpawu zoomatshini zeesampulu zonakaliswe kakhulu, kwaye kwakukho ukugqwala okucacileyo kwisakhiwo se-fracture microstructure, imingxunya yesibini kunye neemveliso ezininzi zokugqwala. Xa uxinzelelo lwesisombululo sokugqwala esilinganisiweyo lunyuswe ukusuka kuma-20 ukuya kuma-200 amaxesha oxinzelelo lwesisombululo sokugqwala esilinganisiweyo sokuqala, impembelelo yoxinzelelo lwesisombululo sokugqwala kwiimpawu zoomatshini zezinto yabuthathaka.
Xa ubushushu bokugqwala obulinganiswayo buyi-25℃, amandla okukhupha kunye namandla okutsalwa kweesampuli ze-bolt ezinamandla aphezulu ze-20MnTiB azitshintshi kakhulu xa kuthelekiswa neesampuli ezingagqwalanga. Nangona kunjalo, phantsi kobushushu bokugqwala obulinganiswayo be-50 °C, amandla okutsalwa kunye nokwandiswa kwesampuli kwehla kakhulu, izinga lokuncitshiswa kwecandelo lalisondele kwixabiso eliqhelekileyo, i-fracture shear lip yayiyeyona inkulu, kwaye kwakukho ii-dimples kwindawo yefayibha ephakathi. Ukwanda okukhulu, ubunzulu bomngxuma buyanda, iimveliso zokugqwala kunye nemingxunya yokugqwala yanda. Oku kubonisa ukuba imeko yobushushu yokugqwala ehambelanayo inempembelelo enkulu kwiimpawu zoomatshini zeebholts ezinamandla aphezulu, ezingacacanga kubushushu begumbi, kodwa zibaluleke ngakumbi xa ubushushu bufikelela kwi-50 °C.
Emva kovavanyo lokugqwala olukhawulezileyo lwangaphakathi olulinganisa imeko-bume yomoya eChongqing, amandla okutsalwa, amandla okukhupha, ukunwebeka kunye nezinye iiparameter ze-20MnTiB high-strength bolts zinciphile, kwaye kwenzeka umonakalo ocacileyo woxinzelelo. Ekubeni izinto ziphantsi koxinzelelo, kuya kubakho into ebalulekileyo yokukhawulezisa ukugqwala kwindawo ethile. Kwaye ngenxa yesiphumo esidibeneyo soxinzelelo kunye nemingxunya yokugqwala, kulula ukubangela umonakalo ocacileyo weplastiki kwi-high-strength bolts, ukunciphisa amandla okumelana nokuguquguquka kwamandla angaphandle, kunye nokwandisa ukuthambekela kokugqwala koxinzelelo.
ULi, G., uLi, M., uYin, uY. kunye noJiang, S. Uphononongo lovavanyo malunga neempawu zeebholiti ezinamandla aphezulu ezenziwe ngentsimbi ye-20MnTiB kubushushu obuphezulu. umhlathi. Ubunjineli bokwakha. J. 34, 100–105 (2001).
UHu, J., uZou, D. kunye noYang, Q. Uhlalutyo lokungaphumeleli kokwaphuka kweebholiti zentsimbi ezingama-20MnTiB ezinamandla aphezulu kwiireyile. unyango lobushushu. Isinyithi.42, 185–188 (2017).
Catar, R. & Altun, H. Ukuziphatha kokuqhekeka koxinzelelo lwe-Mg-Al-Zn alloys phantsi kweemeko ezahlukeneyo ze-pH ngendlela ye-SSRT.Open.Chemical.17, 972–979 (2019).
UNazer, AA nabanye. Iziphumo ze-glycine kwindlela yokugaya i-electrochemical kunye ne-stress corrosion ye-Cu10Ni alloy kwi-brine engcolileyo ye-sulfide. I-Industrial Engineering.Chemical.reservoir.50, 8796–8802 (2011).
Aghion, E. kunye noLulu, N. Iipropati zokugqwala kwe-die-cast magnesium alloy MRI230D kwisisombululo se-Mg(OH)2-saturated 3.5% NaCl.alma mater.character.61, 1221–1226 (2010).
UZhang, Z., Hu, Z. kunye noPreet, MS Impembelelo yee-ion ze-chloride kwi-static kunye ne-stress corrosion behavior ye-9Cr martensitic steel.surf.Technology.48, 298–304 (2019).
UChen, X., Ma, J., Li, X., Wu, M. kunye noSong, B. Isiphumo esidibeneyo se-SRB kunye nobushushu ekuqhekekeni koxinzelelo lwentsimbi ye-X70 kwisisombululo sodaka lolwandle esenziwe ngokwenziwa. J. Chin.Socialist Party.coros.Pro.39, 477–484 (2019).
ULiu, J., Zhang, Y. kunye noYang, S. Ukuziphatha kokugqwala koxinzelelo lwentsimbi engagqwaliyo ye-00Cr21Ni14Mn5Mo2N emanzini olwandle.physics. thatha uvavanyo.36, 1-5 (2018).
ULu, C. Uphononongo olucothayo lokuqhekeka kweebhulorho ezinamandla aphezulu. umhlathi. Isikolo semfundo. isayensi yesitimela.2, 10369 (2019).
UAnanya, B. Ukuqhekeka koxinzelelo lokugqwala kweentsimbi ezi-stainless ezimbini kwizisombululo ze-caustic. I-Doctoral Dissertation, e-Atlanta, e-GA, e-USA: I-Georgia Institute of Technology 137–8 (2008)
ISunada, S., Masanori, K., Kazuhiko, M. kunye noSugimoto, K. Iziphumo ze-H2SO4 kunye noxinzelelo lwe-naci ekuqhekekeni koxinzelelo lwe-SUS304 stainless steel kwisisombululo samanzi se-H2SO4-NaCl.alma mater.trans.47, 364–370 (2006).
IMerwe, JWVD Impembelelo yendalo kunye nezinto ekuqhekekeni koxinzelelo lokubola kwentsimbi kwisisombululo se-H2O/CO/CO2. Inter Milan.J. Koros.2012, 1-13 (2012).
U-Ibrahim, M. kunye no-Akram A. Iziphumo ze-bicarbonate, ubushushu kunye ne-pH ekudlulisweni kwentsimbi yombhobho we-API-X100 kwisisombululo samanzi angaphantsi komhlaba esilinganisiweyo. Kwi-IPC 2014-33180.
UShan, G., uChi, uL., uSong, uX., uHuang, uX. kunye noQu, D. Impembelelo yobushushu ekuqhekekeni koxinzelelo lokuqhekeka kwe-austenitic stainless steel.coro.be ngokuchasene ne.Technology.18, 42–44 (2018).
UHan, S. Ukuziphatha okulibazisekileyo kokuqhekeka okubangelwa yi-hydrogen kweentsimbi ezininzi zokubopha ezinamandla aphezulu (iKunming University of Science and Technology, 2014).
Zhao, B., Zhang, Q. kunye noZhang, M. Indlela yokunciphisa uxinezeleko lwe-GH4080A alloy kwi-fasteners.cross.companion.Hey.treat.41, 102–110 (2020).