I-scanning electron microscope yasetyenziswa ukujonga ukwaphuka kokudinwa kunye nokuhlalutya indlela yokuqhekeka; kwangaxeshanye, uvavanyo lokudinwa olujikajikayo lwenziwa kwiisampuli ezisuswe iikhabhoni kubushushu obahlukeneyo ukuze kuthelekiswe ubomi bokudinwa kwentsimbi yovavanyo kunye nokungabikho kwayo, kunye nokuhlalutya isiphumo sokususwa kweekhabhoni ekusebenzeni kokudinwa kwentsimbi yovavanyo. Iziphumo zibonisa ukuba, ngenxa yokubakho ngaxeshanye kwe-oxidation kunye ne-decarburization kwinkqubo yokufudumeza, ukusebenzisana phakathi kwezi zimbini, okubangela ukuba ubukhulu bomaleko osuswe iikhabhoni ngokupheleleyo kunye nokukhula kobushushu kubonisa umkhwa wokwanda nokwehla, ubukhulu bomaleko osuswe iikhabhoni ngokupheleleyo bufikelela kwixabiso eliphezulu le-120 μm kwi-750 ℃, kwaye ubukhulu bomaleko osuswe iikhabhoni ngokupheleleyo bufikelela kwixabiso elincinci le-20 μm kwi-850 ℃, kwaye umda wokudinwa kwentsimbi yovavanyo umalunga ne-760 MPa, kwaye umthombo weentanda zokudinwa kwintsimbi yovavanyo ikakhulu yi-Al2O3 non-metallic inclusions; Indlela yokususa iikhabhohayidreyithi inciphisa kakhulu ubomi bokudinwa kwentsimbi yovavanyo, nto leyo echaphazela ukusebenza kokudinwa kwentsimbi yovavanyo, okukhona umaleko wokususa iikhabhohayidreyithi utyebile, kokukhona ubomi bokudinwa buphantsi. Ukuze kuncitshiswe impembelelo yomaleko wokususa iikhabhohayidreyithi ekusebenzeni kokudinwa kwentsimbi yovavanyo, ubushushu obufanelekileyo bonyango lobushushu bentsimbi yovavanyo kufuneka bubekwe kwi-850℃.
Izixhobo ziyinxalenye ebalulekileyo yemotoNgenxa yokusebenza ngesantya esiphezulu, inxalenye ye-meshing yomphezulu wegiya kufuneka ibe namandla aphezulu kunye nokumelana nokukrala, kwaye ingcambu yamazinyo kufuneka ibe nokusebenza kakuhle kokudinwa kokugoba ngenxa yomthwalo ophindaphindwayo rhoqo, ukuze kuthintelwe ukuqhekeka okukhokelela ekuqhekekeni kwezinto. Uphando lubonisa ukuba ukugutyungelwa kwekhabhoni yinto ebalulekileyo echaphazela ukusebenza kokudinwa kokugoba kwezinto zesinyithi, kwaye ukusebenza kokudinwa kokugoba kwekhabhoni luphawu olubalulekileyo lomgangatho wemveliso, ngoko ke kuyimfuneko ukufunda indlela yokuziphatha yokugutyungelwa kwekhabhoni kunye nokusebenza kokudinwa kokugoba kwezixhobo zovavanyo.
Kule phepha, isithando sonyango lobushushu kuvavanyo lwe-20CrMnTi gear steel surface decarburization, sihlalutya amaqondo obushushu ahlukeneyo kubunzulu bomaleko we-test steel decarburization womthetho otshintshayo; kusetyenziswa umatshini wovavanyo lokudinwa we-QBWP-6000J olula we-beam kwi-test steel rotary bending fatigue test, ukumisela ukusebenza kokudinwa kwe-test steel, kwaye kwangaxeshanye sihlalutye impembelelo ye-decarburization kwi-fatigue function ye-test steel kwimveliso yokwenyani ukuphucula inkqubo yemveliso, ukuphucula umgangatho weemveliso kunye nokubonelela ngereferensi efanelekileyo. Ukusebenza kokudinwa kwe-test steel test kumiselwa ngumatshini wovavanyo lokudinwa we-spin bending.
1. Izixhobo zovavanyo kunye neendlela
Izinto zovavanyo zeyunithi yokubonelela ngentsimbi yegiya ye-20CrMnTi, eyona khemikhali iphambili njengoko kubonisiwe kwiTheyibhile 1. Uvavanyo lokususa iikhabhohayidreyithi: izinto zovavanyo zicutshungulwa zibe yisampuli ye-F8 mm × 12 mm esilinda, umphezulu kufuneka ukhanye ngaphandle kwamabala. Isithando sonyango lobushushu sifudunyezwe ukuya kuma-675 ℃, 700 ℃, 725 ℃, 750 ℃, 800 ℃, 850 ℃, 900 ℃, 950 ℃, 1,000 ℃, kwisampuli kwaye sibambe iyure e-1, size sipholiswe ngumoya ukuya kubushushu begumbi. Emva konyango lobushushu lwesampuli ngokubeka, ukugaya kunye nokupolisha, kunye ne-4% yesisombululo sotywala se-nitric acid ukukhukuliseka, ukusetyenziswa kwe-metallurgical microscopy ukujonga umaleko wokususa iikhabhohayidreyithi zentsimbi yovavanyo, ukulinganisa ubunzulu bomaleko wokususa iikhabhohayidreyithi kumaqondo obushushu ahlukeneyo. Uvavanyo lokudinwa lokujikajika: izixhobo zovavanyo ngokweemfuno zokucutshungulwa kwamaqela amabini eesampuli zokudinwa zokujikajika, iqela lokuqala alilwenzi uvavanyo lokujikajika, iqela lesibini lovavanyo lokujikajika kumaqondo obushushu ahlukeneyo. Kusetyenziswa umatshini wovavanyo lokudinwa lokujikajika, amaqela amabini entsimbi yovavanyo lovavanyo lokujikajikajika, ukumisela umda wokudinwa kwamaqela amabini entsimbi yovavanyo, uthelekiso lobomi bokudinwa kwamaqela amabini entsimbi yovavanyo, ukusetyenziswa kwe-scanning electron microscope fatigue fracture observation, ukuhlalutya izizathu zokuqhekeka kwesampuli, ukuphonononga isiphumo sokujikajika kweepropati zokudinwa zentsimbi yovavanyo.
Itheyibhile 1 Ulwakhiwo lweekhemikhali (inxalenye yobunzima) yentsimbi yovavanyo ubunzima%
Impembelelo yobushushu bokufudumeza ekususweni kwekhabhohayidreyithi
Indlela ehlelwe ngayo inkqubo yokususa iicarburization phantsi kwamaqondo obushushu ahlukeneyo iboniswe kwiFig. 1. Njengoko kunokubonwa kumfanekiso, xa amaqondo obushushu angama-675 ℃, umphezulu wesampuli awubonakali umaleko wokususa iicarburization; xa amaqondo obushushu enyuka ukuya kwi-700 ℃, umaleko wokususa iicarburization kumphezulu wesampuli waqala ukubonakala, kumaleko obhityileyo wokususa iicarburization; xa amaqondo obushushu enyuka ukuya kwi-725 ℃, ubukhulu bomaleko wokususa iicarburization kumphezulu wesampuli bunyuke kakhulu; ubukhulu bomaleko wokususa iicarburization obuyi-750 ℃ bufikelela kwixabiso eliphezulu, ngeli xesha, ingqolowa yeferrite icacile ngakumbi, irhabaxa; xa amaqondo obushushu enyuka ukuya kwi-800 ℃, ubukhulu bomaleko wokususa iicarburization baqala ukwehla kakhulu, ubukhulu bayo behla ukuya kwisiqingatha se-750 ℃; xa amaqondo obushushu eqhubeka enyuka ukuya kwi-850 ℃ kwaye ubukhulu bokususa iicarburization buboniswe kwiFig. 1. 800 ℃, ubukhulu bomaleko wokususa iicarburization buqale ukwehla kakhulu, ubukhulu bayo behla ukuya kwi-750 ℃ xa isiqingatha; Xa ubushushu buqhubeka bunyuka bufikelela kwi-850 ℃ nangaphezulu, ubukhulu bomaleko we-decarburization wentsimbi epheleleyo buyaqhubeka nokuncipha, ubukhulu bomaleko we-decarburization obuphakathi buqale ukwanda kancinci kancinci de i-decarburization layer morphology yonke inyamalale, i-decarburization layer morphology engaphantsi kancinci kancinci icacile. Kuyabonakala ukuba ubukhulu bomaleko we-decarburization obupheleleyo kunye nokunyuka kobushushu buqale banda baze bancitshiswe, isizathu sale nto kungenxa yesampulu kwinkqubo yokufudumeza ngaxeshanye ukuziphatha kwe-oxidation kunye ne-decarburization, kuphela xa izinga le-decarburization likhawuleza kunesantya se-oxidation kuya kuvela i-decarburization phenomenon. Ekuqaleni kokufudumeza, ubukhulu bomaleko we-decarburization obupheleleyo buyanda kancinci kancinci ngokunyuka kobushushu de ubukhulu bomaleko we-decarburization bufikelele kwixabiso eliphezulu, ngeli xesha ukuqhubeka nokuphakamisa ubushushu, izinga le-oxidation yesampuli likhawuleza kunezinga le-decarburization, elithintela ukwanda komaleko we-decarburization obupheleleyo, okubangela ukuhla. Kuyabonakala ukuba, ngaphakathi koluhlu lwe-675 ～950 ℃, ixabiso lobukhulu belaphu elikhutshwe ngokupheleleyo kwi-750 ℃ lelona likhulu, kwaye ixabiso lobukhulu belaphu elikhutshwe ngokupheleleyo kwi-850 ℃ lelona lincinci, ngoko ke, ubushushu bokufudumeza bentsimbi yovavanyo bucetyiswa ukuba bube yi-850 ℃.
Umzobo 1 I-Histomorphology yomaleko okhutshwe kwikhabhoni wentsimbi yovavanyo ebanjwe kumaqondo obushushu ahlukeneyo kangangeyure eli-1
Xa kuthelekiswa nomaleko osuswe ngokupheleleyo kwikhabhathi, ubukhulu bomaleko osuswe ngokupheleleyo kwikhabhathi bunempembelelo embi kakhulu kwiimpawu zezinto, buya kunciphisa kakhulu iimpawu zoomatshini zezinto, ezinje ngokunciphisa amandla, ubulukhuni, ukumelana nokuguguleka kunye nomda wokudinwa, njl.njl., kwaye bukwandise uvakalelo kwiintanda, okuchaphazela umgangatho wokuwelda njalo njalo. Ke ngoko, ukulawula ubukhulu bomaleko osuswe ngokupheleleyo kwikhabhathi kubaluleke kakhulu ukuphucula ukusebenza kwemveliso. Umfanekiso 2 ubonisa ijika lokuguquguquka kobukhulu bomaleko osuswe ngokupheleleyo kwikhabhathi kunye nobushushu, okubonisa utshintsho lobukhulu bomaleko osuswe ngokupheleleyo kwikhabhathi ngokucacileyo. Kunokubonwa kumfanekiso ukuba ubukhulu bomaleko osuswe ngokupheleleyo kwikhabhathi bumalunga ne-34μm kuphela kwi-700℃; xa ubushushu bunyuka busiya kwi-725 ℃, ubukhulu bomaleko osuswe ngokupheleleyo kwikhabhathi buyanda kakhulu ukuya kwi-86 μm, engaphezulu kwezihlandlo ezibini zobukhulu bomaleko osuswe ngokupheleleyo kwi-700 ℃; xa ubushushu bunyuswa bufikelela kwi-750 ℃, ubukhulu bomaleko osuswe ngokupheleleyo kwikhabhoni Xa ubushushu bunyuka bufikelela kwi-750 ℃, ubukhulu bomaleko osuswe ngokupheleleyo kwikhabhoni bufikelela kwixabiso eliphezulu le-120 μm; njengoko ubushushu buqhubeka bunyuka, ubukhulu bomaleko osuswe ngokupheleleyo kwikhabhoni buqala ukwehla ngokukhawuleza, ukuya kwi-70 μm kwi-800 ℃, kwaye emva koko bufikelele kwixabiso elincinci elimalunga ne-20 μm kwi-850 ℃.
Umfanekiso 2 Ubukhulu bomaleko okhutshwe ngokupheleleyo kwiqondo lobushushu obahlukeneyo
Isiphumo sokususwa kwekhabhohayidreyithi ekusebenzeni kokudinwa ekugobeni kwe-spin
Ukuze kufundwe impembelelo yokususwa kwekhabhoni kwiimpawu zokudinwa zentsimbi yentwasahlobo, kwenziwe amaqela amabini ovavanyo lokudinwa olujikajikayo, iqela lokuqala lavavanywa ngokuthe ngqo ngaphandle kokususwa kwekhabhoni, kwaye iqela lesibini lavavanywa ukudinwa emva kokususwa kwekhabhoni kwinqanaba elifanayo loxinzelelo (810 MPa), kwaye inkqubo yokususwa kwekhabhoni yabanjwa kwi-700-850 ℃ kangangeyure e-1. Iqela lokuqala leesampuli liboniswe kwiTheyibhile 2, elibubomi bokudinwa kwentsimbi yentwasahlobo.
Ubomi bokudinwa kweqela lokuqala leesampuli buboniswe kwiTheyibhile 2. Njengoko kunokubonwa kwiTheyibhile 2, ngaphandle kokususwa kwekhabhoni, intsimbi yovavanyo yafakwa kuphela kwimijikelo eyi-107 kwi-810 MPa, kwaye akukho kwaphuka kwenzeke; xa inqanaba loxinzelelo lidlule kwi-830 MPa, ezinye zeesampuli zaqala ukwaphuka; xa inqanaba loxinzelelo lidlule kwi-850 MPa, zonke iisampuli zokudinwa zaqhekeka.
Itheyibhile 2 Ubomi bokudinwa phantsi kwamanqanaba ahlukeneyo oxinzelelo (ngaphandle kokususwa kwekhabhohayidreyithi)
Ukuze kuchongwe umda wokudinwa, indlela yeqela isetyenziselwa ukumisela umda wokudinwa kwentsimbi yovavanyo, kwaye emva kohlalutyo lweenkcukacha-manani lwedatha, umda wokudinwa kwentsimbi yovavanyo umalunga ne-760 MPa; ukuze kuchazwe ubomi bokudinwa kwentsimbi yovavanyo phantsi koxinzelelo olwahlukeneyo, ijika le-SN lidwetshwe, njengoko kubonisiwe kuMfanekiso 3. Njengoko kunokubonwa kuMfanekiso 3, amanqanaba ahlukeneyo oxinzelelo ahambelana nobomi bokudinwa obahlukeneyo, xa ubomi bokudinwa buyi-7, buhambelana nenani lemijikelo ye-107, oko kuthetha ukuba isampuli phantsi kwezi meko idlula kwimeko, ixabiso loxinzelelo elihambelanayo linokulinganiswa njengexabiso lamandla okudinwa, oko kukuthi, i-760 MPa. Kunokubonwa ukuba ijika le-S-N libalulekile ekumiselweni kobomi bokudinwa kwezinto linexabiso elibalulekileyo lesalathiso.
Umfanekiso 3 SN curve yovavanyo lokudinwa lokugoba ngentsimbi ejikelezayo
Ubomi bokudinwa kweqela lesibini leesampuli buboniswe kwiTheyibhile 3. Njengoko kunokubonwa kwiTheyibhile 3, emva kokuba intsimbi yovavanyo isusiwe iikhabhathi kumaqondo obushushu ahlukeneyo, inani lemijikelo liyancitshiswa ngokucacileyo, kwaye lingaphezulu kwe-107, kwaye zonke iisampuli zokudinwa ziyaqhekeka, kwaye ubomi bokudinwa buncitshiswa kakhulu. Xa zidityaniswe nobukhulu bomaleko obususiwe iikhabhathi obungentla kunye nejika lotshintsho lobushushu lingabonwa, ubukhulu bomaleko obususiwe iikhabhathi obuyi-750 ℃ yeyona inkulu, ehambelana nexabiso eliphantsi lobomi bokudinwa. Ubukhulu bomaleko obususiwe iikhabhathi obuyi-850 ℃ buncinci, obuhambelana nexabiso lobomi bokudinwa liphezulu. Kunokubonwa ukuba ukuziphatha kokususwa kweekhabhathi kunciphisa kakhulu ukusebenza kokudinwa kwezinto, kwaye okukhona umaleko osusiwe iikhabhathi utyebile, kokukhona ubomi bokudinwa buphantsi.
Itheyibhile 3 Ubomi bokudinwa kumaqondo obushushu ahlukeneyo okususa iikhabhohayidreyithi (560 MPa)
Imofoloji yokuqhekeka kokudinwa kwesampuli ibonwe ngokuskena imakroskopu ye-electron, njengoko kubonisiwe kwiFig. 4. Umfanekiso 4(a) kwindawo yomthombo wokuqhekeka, umfanekiso unokubonwa i-arc yokudinwa ecacileyo, ngokwe-arc yokudinwa ukufumana umthombo wokudinwa, unokubonwa, umthombo wokuqhekeka we-"fish-eye" inclusions ezingezizo zesinyithi, i-inclusions kwi-concentration yoxinzelelo elula ukuyibangela, okubangela ukuqhekeka kokudinwa; Umfanekiso 4(b) wemofoloji yendawo yolwandiso lokuqhekeka, unokubonwa imivimbo yokudinwa ecacileyo, yayisasazeko elifana nomlambo, imele ukwaphuka okungadibaniyo, kunye nokuqhekeka okwandileyo, ekugqibeleni okukhokelela ekuqhekekeni. Umfanekiso 4(b) ubonisa imofoloji yendawo yokwandiswa kokuqhekeka, imivimbo yokudinwa ecacileyo inokubonwa, ngendlela yokwabiwa okufana nomlambo, okumele ukwaphuka okungadibaniyo, kunye nokwanda okuqhubekayo kokuqhekeka, ekugqibeleni okukhokelela ekuqhekekeni.
Uhlalutyo lokuqhekeka kokudinwa
Umfanekiso 4 Imo ye-SEM yomphezulu wokuqhekeka kokudinwa kwentsimbi yovavanyo
Ukuze kuchongwe uhlobo lwezinto ezifakiweyo kuMfanekiso 4, kwenziwe uhlalutyo lokwakheka kwe-energy spectrum, kwaye iziphumo ziboniswe kuMfanekiso 5. Kuyabonakala ukuba izinto ezingezizo ezesinyithi ikakhulu ziizinto ezifakiweyo ze-Al2O3, nto leyo ebonisa ukuba ezo zinto zifakiweyo zingumthombo ophambili weentanda ezibangelwa kukuqhekeka kwezinto ezifakiweyo.
Umfanekiso 5 I-Energy Spectroscopy yezinto ezingezizo ezesinyithi
Gqibezela
(1) Ukubeka ubushushu bokufudumeza kwi-850 ℃ kuya kunciphisa ubukhulu bomaleko osusiweyo kwikhabhoni ukunciphisa impembelelo ekusebenzeni kokudinwa.
(2) Umda wokudinwa kokugoba kwentsimbi yovavanyo yi-760 MPa.
(3) Uvavanyo lokuqhekeka kwentsimbi kwizinto ezingezizo ezesinyithi, ikakhulu umxube we-Al2O3.
(4) ukususwa kwekhabhohayidreyithi kunciphisa kakhulu ubomi bokudinwa kwentsimbi yovavanyo, okukhona umaleko wokususwa kwekhabhohayidreyithi utyebile, kokukhona ubomi bokudinwa buphantsi.
Ixesha leposi: Juni-21-2024
