Inkcazo kunye nenjongo yokucima
Intsimbi ifudunyezwa ifikelele kubushushu obungaphezulu kwe-critical point Ac3 (intsimbi ye-hypoeutectoid) okanye i-Ac1 (intsimbi ye-hypereutectoid), igcinwa ixesha elithile ukuze ikwazi ukunyibilika ngokupheleleyo okanye ngokuyinxenye, ize ipholiswe ngesantya esiphezulu kunesantya sokucima esibalulekileyo. Inkqubo yonyango lobushushu eguqula i-austenite epholileyo ibe yi-martensite okanye i-bainite esezantsi ibizwa ngokuba yi-quenching.
Injongo yokucima kukuguqula i-austenite epholileyo ibe yi-martensite okanye i-bainite ukuze kufunyanwe isakhiwo se-martensite okanye esisezantsi se-bainite, esidityaniswa nokufudumala kumaqondo obushushu ahlukeneyo ukuphucula kakhulu amandla, ubulukhuni, kunye nokumelana kwentsimbi. Ukuguguleka, amandla okudinwa kunye nokuqina, njl.njl., ukuhlangabezana neemfuno ezahlukeneyo zokusetyenziswa kwezixhobo ezahlukeneyo zoomatshini kunye nezixhobo. Ukucima kungasetyenziselwa ukuhlangabezana neempawu ezikhethekileyo zomzimba nezekhemikhali zeentsimbi ezithile ezikhethekileyo ezifana ne-ferromagnetism kunye nokumelana nokugqwala.
Xa iindawo zentsimbi zipholiswa kwindawo yokucima umlilo kunye notshintsho kwimo yomzimba, inkqubo yokupholisa ngokubanzi yahlulwe yangamanqanaba amathathu alandelayo: isigaba sefilimu yomphunga, isigaba sokubilisa, kunye nesigaba se-convection.
Ukuqina kwentsimbi
Ukuqina nokuqina zizibonakaliso ezimbini zokusebenza ezibonisa amandla entsimbi okucima. Zikwabalulekile ekukhetheni nasekusebenziseni izinto.
1. Iingcamango zokuqina kunye nokuqina
Ukuqina kwentsimbi kukukwazi kwentsimbi ukufikelela kobona bunzima buphezulu obunokufikelelwa xa icinyiwe kwaye iqiniswe phantsi kweemeko ezifanelekileyo. Eyona nto iphambili emisela ukuqina kwentsimbi ngumxholo wekhabhoni wentsimbi. Ukuchaneka ngakumbi, ngumxholo wekhabhoni onyibilikisiweyo kwi-austenite ngexesha lokucima nokufudumeza. Okukhona umxholo wekhabhoni uphezulu, kokukhona ukuqina kwentsimbi kuphezulu. Izinto ezidibanisa intsimbi azinampembelelo ingako ekuqineni kwayo, kodwa zinempembelelo ebalulekileyo ekuqineni kwentsimbi.
Ukuqina kubhekisa kwiimpawu ezimisela ubunzulu bokuqina kunye nokusasazwa kobunzima bentsimbi phantsi kweemeko ezithile. Oko kukuthi, ukukwazi ukufumana ubunzulu bomaleko oqinisiweyo xa intsimbi icinyiwe. Yimpawu yendalo yentsimbi. Ukuqina kubonisa ngokulula i-austenite eguquka ngayo ibe yi-martensite xa intsimbi icinyiwe. Inxulumene kakhulu nokuzinza kwe-austenite epholileyo kakhulu yentsimbi, okanye kwizinga lokupholisa elibalulekileyo lentsimbi.
Kufuneka kuqatshelwe ukuba ukuqina kwentsimbi kufuneka kwahlulwe kubunzulu bokuqina obusebenzayo beendawo zentsimbi phantsi kweemeko ezithile zokucinywa. Ukuqina kwentsimbi yipropati yendalo yentsimbi ngokwayo. Ixhomekeke kuphela kwizinto zayo zangaphakathi kwaye ayinanto yakwenza nezinto zangaphandle. Ubunzulu bokuqina kwentsimbi obusebenzayo abuxhomekekanga kuphela ekuqineni kwentsimbi, kodwa buxhomekeke nakwizinto ezisetyenzisiweyo. Inxulumene nezinto zangaphandle ezifana nendawo yokuphola kunye nobukhulu beendawo zokusebenza. Umzekelo, phantsi kweemeko ezifanayo zokuqiniswa, ukuqina kwentsimbi efanayo kuyafana, kodwa ubunzulu bokuqina obusebenzayo bokucima amanzi bukhulu kunobo bokucima ioyile, kwaye iindawo ezincinci zincinci kunokucima ioyile. Ubunzulu bokuqina obusebenzayo beendawo ezinkulu bukhulu. Oku akunakutshiwo ukuba ukucima amanzi kunokuqina okuphezulu kunokucima ioyile. Akunakuthiwa iindawo ezincinci zinokuqina okuphezulu kuneendawo ezinkulu. Kunokubonwa ukuba ukuvavanya ukuqina kwentsimbi, impembelelo yezinto zangaphandle ezifana nesimo seendawo zokusebenza, ubungakanani, indawo yokuphola, njl. kufuneka isuswe.
Ukongeza, ekubeni ukuqina nokuqina ziingcinga ezimbini ezahlukeneyo, intsimbi enobunzima obuphezulu emva kokucinywa ayisoloko inobunzima obuphezulu; kwaye intsimbi enobunzima obuphantsi isenokuba nobunzima obuphezulu.
2. Izinto ezichaphazela ukuqina
Ukuqina kwentsimbi kuxhomekeke ekuzinzeni kwe-austenite. Nasiphi na isiza esinokuphucula ukuzinza kwe-austenite epholileyo kakhulu, sitshintshe ijika le-C liye ngasekunene, ngaloo ndlela sinciphise izinga lokupholisa elibalulekileyo, sinokuphucula ukuqina kwentsimbi ephezulu. Ukuqina kwe-austenite kuxhomekeke kakhulu kukwakheka kwayo kweekhemikhali, ubungakanani beenkozo kunye nokufana kokwakheka kwayo, okunxulumene nokwakheka kweekhemikhali zentsimbi kunye neemeko zokufudumeza.
3. Indlela yokulinganisa ubulukhuni
Kukho iindlela ezininzi zokulinganisa ukuqina kwentsimbi, ezona zisetyenziswa kakhulu yindlela yokulinganisa ububanzi obubalulekileyo kunye nendlela yokuvavanya ukuqina kokuphela.
(1) Indlela yokulinganisa ububanzi obubalulekileyo
Emva kokuba intsimbi icinyiwe kwindawo ethile, ubukhulu becala xa umbindi ufumana yonke i-martensite okanye isakhiwo se-martensite esingama-50% sibizwa ngokuba yi-critical diameter, emelwe yi-Dc. Indlela yokulinganisa ubukhulu becala kukwenza uthotho lweentonga ezijikelezileyo ezinobubanzi obahlukeneyo, kwaye emva kokucima, ulinganise ubunzima be-U curve esasazwe kububanzi kwicandelo ngalinye lesampuli, kwaye ufumane intonga enesakhiwo se-semi-martensite embindini. Ububanzi bentonga ejikelezileyo Yiyo loo nto ububanzi becala. Okukhona ubukhulu becala bubukhulu, kokukhona ukuqina kwentsimbi kuphezulu.
(2) Indlela yovavanyo lokuphelisa ukucima
Indlela yovavanyo lokucima isiphelo isebenzisa isampuli yokucima isiphelo enobukhulu obuqhelekileyo (Ф25mm × 100mm). Emva kokuvuselelwa, amanzi atshizwa kwelinye icala lesampuli kwizixhobo ezikhethekileyo ukuze iphole. Emva kokupholisa, ubunzima bulinganiswa kwicala le-axis - ukusuka kwisiphelo esipholileyo ngamanzi. Indlela yokuvavanya ijika lobudlelwane bomgama. Indlela yokuvavanya ukuqina kwesiphelo yenye yeendlela zokufumanisa ukuqina kwentsimbi. Iingenelo zayo kukusebenza okulula kunye noluhlu olubanzi lokusetyenziswa.
4. Ukucima uxinzelelo, ukuguqulwa kunye nokuqhekeka
(1) Uxinzelelo lwangaphakathi lomsebenzi ngexesha lokucima
Xa i-workpiece ipholiswa ngokukhawuleza kwindawo yokucima, ekubeni i-workpiece inobukhulu obuthile kwaye i-thermal conductivity coefficient nayo inexabiso elithile, i-gradient ethile yobushushu iya kwenzeka ecaleni kwecandelo langaphakathi le-workpiece ngexesha lenkqubo yokupholisa. Ubushushu bomphezulu buphantsi, ubushushu obuphambili buphezulu, kwaye ubushushu bomphezulu kunye nobushushu obuphambili buphezulu. Kukho umahluko wobushushu. Ngexesha lenkqubo yokupholisa ye-workpiece, kukwakho neziganeko ezimbini ezibonakalayo: enye kukwanda kobushushu, njengoko ubushushu buhla, ubude bomgca we-workpiece buya kuncipha; enye kukuguqulwa kwe-austenite ukuya kwi-martensite xa ubushushu buhla ukuya kwindawo yokuguqula i-martensite. , eya kunyusa umthamo othile. Ngenxa yomahluko wobushushu ngexesha lenkqubo yokupholisa, ubungakanani bokwanda kobushushu buya kwahluka kwiindawo ezahlukeneyo ecaleni kwecandelo le-workpiece, kwaye uxinzelelo lwangaphakathi luya kuveliswa kwiindawo ezahlukeneyo ze-workpiece. Ngenxa yokubakho komahluko wobushushu ngaphakathi kwe-workpiece, kunokubakho iindawo apho ubushushu buhla ngokukhawuleza kunendawo apho i-martensite yenzeka khona. Utshintsho, umthamo uyanda, kwaye iindawo ezinobushushu obuphezulu zisephezulu kunenqaku kwaye zisekwimeko ye-austenite. Ezi ndawo zahlukeneyo ziya kuvelisa uxinzelelo lwangaphakathi ngenxa yomahluko kutshintsho oluthile lomthamo. Ke ngoko, iintlobo ezimbini zoxinzelelo lwangaphakathi zinokuveliswa ngexesha lenkqubo yokucinywa kunye nokupholisa: olunye luxinzelelo lobushushu; olunye luxinzelelo lwezicubu.
Ngokweempawu zexesha lobukho boxinzelelo lwangaphakathi, lunokwahlulwahlulwa lube luxinzelelo olukhawulezileyo kunye noxinzelelo olushiyekileyo. Uxinzelelo lwangaphakathi oluveliswa yi-workpiece ngexesha elithile ngexesha lenkqubo yokupholisa lubizwa ngokuba luxinzelelo olukhawulezileyo; emva kokuba i-workpiece ipholile, uxinzelelo olusele ngaphakathi kwi-workpiece lubizwa ngokuba luxinzelelo olushiyekileyo.
Uxinzelelo lobushushu lubhekisa kuxinzelelo olubangelwa kukwanda kobushushu okungaguqukiyo (okanye ukuxinana okubandayo) ngenxa yokwahluka kobushushu kwiindawo ezahlukeneyo zomsebenzi xa ushushu (okanye upholile).
Ngoku thabatha isilinda esiqinileyo njengomzekelo ukubonisa ukwakheka notshintsho lwemithetho yoxinzelelo lwangaphakathi ngexesha lenkqubo yalo yokupholisa. Kuphela kuxoxwa ngoxinzelelo lwe-axial apha. Ekuqaleni kokupholisa, kuba umphezulu uphola ngokukhawuleza, ubushushu buphantsi, kwaye buncipha kakhulu, ngelixa umongo upholisiwe, ubushushu buphezulu, kwaye ukuncipha kuncinci. Ngenxa yoko, umphezulu kunye nongaphakathi zithintelwe ngokulinganayo, okubangela uxinzelelo lokuxinana kumphezulu, ngelixa umongo uphantsi koxinzelelo. Njengoko ukupholisa kuqhubeka, umahluko wobushushu phakathi kwangaphakathi nangaphandle uyanda, kwaye uxinzelelo lwangaphakathi nalo luyanda ngokufanelekileyo. Xa uxinzelelo lusanda ukuze ludlule amandla okuvelisa kolu bushushu, kwenzeka ukuguquguquka kweplastiki. Ekubeni ubukhulu bentliziyo buphezulu kunobomphezulu, intliziyo ihlala incipha nge-axial kuqala. Ngenxa yokuguquguquka kweplastiki, uxinzelelo lwangaphakathi alusekho. Emva kokupholisa ukuya kwixesha elithile, ukwehla kobushushu bomphezulu kuya kuncipha kancinci, kwaye ukuncipha kwayo kuya kuncipha kancinci. Ngeli xesha, umongo usancipha, ngoko uxinzelelo lokuxinana kumphezulu kunye noxinzelelo lokuxinana kumphezulu kuya kuncipha kancinci de kuphele. Nangona kunjalo, njengoko ukupholisa kuqhubeka, ukufuma komphezulu kuya kwehla, kwaye ubungakanani bokuncipha buyancipha, okanye buyeke nokuncipha. Ekubeni ubushushu kumbindi busephezulu, buya kuqhubeka buncipha, kwaye ekugqibeleni uxinzelelo oluxinzelelweyo luya kwenziwa kumphezulu wesixhobo somsebenzi, ngelixa umbindi uya kuba noxinzelelo lokuxinana. Nangona kunjalo, ekubeni ubushushu buphantsi, ukuguquka kweplastiki akulula ukwenzeka, ngoko ke olu xinzelelo luya kwanda njengoko ukupholisa kuqhubeka. Luyaqhubeka lusanda kwaye ekugqibeleni luhlala ngaphakathi kwesixhobo somsebenzi njengoxinzelelo olushiyekileyo.
Kuyabonakala ukuba uxinzelelo lobushushu ngexesha lenkqubo yokupholisa ekuqaleni lubangela ukuba umaleko womphezulu wolulwe kwaye umongo ucinezelwe, kwaye uxinzelelo oluseleyo oluseleyo lolo mgangatho womphezulu wolulwe kwaye umongo wolulwe.
Ngamafutshane, uxinzelelo lobushushu oluvela ngexesha lokupholisa olucimayo lubangelwa kukwahluka kobushushu obuphakathi ngexesha lenkqubo yokupholisa. Okukhona izinga lokupholisa liphezulu kwaye umahluko wobushushu obuphakathi umkhulu, kokukhona uxinzelelo lobushushu lukhula. Phantsi kweemeko ezifanayo zokupholisa, kokukhona ubushushu bobushushu bomsebenzi buphezulu, kokhona ubukhulu bukhulu, kokukhona ubushushu bentsimbi buncinci, umahluko wobushushu ngaphakathi komsebenzi, kwaye uxinzelelo lobushushu lukhulu. Ukuba umsebenzi upholiswe ngokungalinganiyo kubushushu obuphezulu, uya kugqwetheka kwaye uguqulwe. Ukuba uxinzelelo loxinzelelo olukhawulezileyo oluvela ngexesha lenkqubo yokupholisa yomsebenzi lukhulu kunamandla oxinzelelo lwezinto, kuya kubakho ukuqhekeka kokucima.
Uxinzelelo lokuguqulwa kwesigaba lubhekisa kuxinzelelo olubangelwa lixesha elahlukileyo lokuguqulwa kwesigaba kwiindawo ezahlukeneyo zomsebenzi ngexesha lenkqubo yonyango lobushushu, okwaziwa ngokuba luxinzelelo lwezicubu.
Ngexesha lokucinywa nokupholisa ngokukhawuleza, xa umaleko womphezulu upholisiwe ukuya kwindawo ye-Ms, utshintsho lwe-martensitic luyenzeka kwaye lubangele ukwanda komthamo. Nangona kunjalo, ngenxa yokuthintelwa kombindi ongekatshintshi, umaleko womphezulu uvelisa uxinzelelo oluxinzelelweyo, ngelixa umbindi unoxinzelelo lokutyhafa. Xa uxinzelelo lukhulu ngokwaneleyo, luya kubangela ukuguqulwa. Xa umbindi upholisiwe ukuya kwindawo ye-Ms, uya kuguqulwa kwakhona kwi-martensitic kwaye wande ngomthamo. Nangona kunjalo, ngenxa yemida yombindi womphezulu oguqulweyo one-plasticity ephantsi kunye namandla aphezulu, uxinzelelo lwawo lokugqibela olushiyekileyo luya kuba ngohlobo loxinzelelo lomphezulu, kwaye umbindi uya kuba phantsi koxinzelelo. Kuyabonakala ukuba utshintsho kunye nemeko yokugqibela yoxinzelelo lotshintsho lwesigaba zichasene ngqo noxinzelelo lobushushu. Ngaphezu koko, ekubeni uxinzelelo lotshintsho lwesigaba lwenzeka kumaqondo obushushu aphantsi ane-plasticity ephantsi, ukuguqulwa kunzima ngeli xesha, ngoko uxinzelelo lotshintsho lwesigaba lunokubangela ukuqhekeka kwesixhobo somsebenzi.
Kukho izinto ezininzi ezichaphazela ubungakanani boxinzelelo lotshintsho lwesigaba. Okukhona izinga lokupholisa lentsimbi likhawuleza kuluhlu lobushushu lotshintsho lwe-martensite, kokukhona ubukhulu besiqwenga sentsimbi bukhulu, kokukhona ukuhanjiswa kobushushu bentsimbi kusiba kubi, kobukhulu bomthamo othile we-martensite, kokukhona uxinzelelo lotshintsho lwesigaba luba lukhulu. Okukhona ikhula. Ukongeza, uxinzelelo lotshintsho lwesigaba lukwanxulumene nokwakheka kwentsimbi kunye nokuqina kwentsimbi. Umzekelo, intsimbi ene-alloy ephezulu enekhabhoni ephezulu yonyusa umthamo othile we-martensite ngenxa yomxholo wayo ophezulu wekhabhoni, omele wonyuse uxinzelelo lotshintsho lwesigaba sentsimbi. Nangona kunjalo, njengoko umxholo wekhabhoni usanda, i-Ms point iyancipha, kwaye kukho inani elikhulu le-austenite egciniweyo emva kokucima. Ukwanda komthamo wayo kuyancipha kwaye uxinzelelo olushiyekileyo luphantsi.
(2) Ukuguqulwa kwesixhobo somsebenzi ngexesha lokucima
Ngexesha lokucinywa, kukho iintlobo ezimbini eziphambili zokuguqulwa kwesimo sendawo yokusebenza: enye kukutshintsha kwesimo sejometri yendawo yokusebenza, okubonakaliswa njengotshintsho kubungakanani nakwimo, okubizwa ngokuba yi-warping deformation, okubangelwa kukuxinezeleka kokucima; enye yi-volume deformation. , ezibonakalisa njengokwandiswa okanye ukucuthwa komthamo wendawo yokusebenza, okubangelwa kukutshintsha komthamo othile ngexesha lotshintsho lwesigaba.
Ukuguquguquka kwe-warping kukwabandakanya ukuguqulwa kwesimo kunye nokuguquguquka kwesimo. Ukuguquguquka kwe-twist kubangelwa ikakhulu kukubekwa ngendlela engafanelekanga kwesixhobo somsebenzi esithandweni ngexesha lokufudumeza, okanye ukungabikho konyango lokubumba emva kokulungiswa kwe-deformation ngaphambi kokucima, okanye ukupholisa okungalinganiyo kwiindawo ezahlukeneyo zomsebenzi xa isixhobo somsebenzi sipholile. Olu tshintsho lunokuhlalutywa kwaye lusonjululwe kwiimeko ezithile. Oku kulandelayo kuxoxa kakhulu ngokuguquguquka kwevolumu kunye nokuguquguquka kwesimo.
1) Izizathu zokucima ukuguquka kwesimo kunye nemithetho etshintshayo
Ukuguquguquka komthamo okubangelwa kukuguquka kolwakhiwo Imeko yolwakhiwo lwesixhobo somsebenzi ngaphambi kokucima idla ngokuba yi-pearlite, oko kukuthi, isakhiwo esixutyiweyo se-ferrite kunye ne-cementite, kwaye emva kokucima sisakhiwo se-martensitic. Iivolumu ezahlukeneyo zezi tissue ziya kubangela utshintsho lomthamo ngaphambi nasemva kokucima, nto leyo ebangela ukuguquguquka. Nangona kunjalo, olu tshintsho lubangela kuphela ukuba isixhobo somsebenzi sande kwaye sinciphe ngokulinganayo, ngoko ke asitshintshi imo yesixhobo somsebenzi.
Ukongeza, okukhona i-martensite ininzi kwisakhiwo emva konyango lobushushu, okanye okukhona umxholo wekhabhoni uphezulu kwi-martensite, kokukhona ukwanda komthamo wayo kukhulu, kwaye okukhona inani le-austenite egciniweyo liphezulu, kokukhona ukwanda komthamo kuncinci. Ke ngoko, utshintsho lomthamo lungalawulwa ngokulawula umxholo ohambelanayo we-martensite kunye ne-martensite eseleyo ngexesha lonyango lobushushu. Ukuba ilawulwa ngokufanelekileyo, umthamo awuyi kwanda okanye unciphe.
Ukuguquka kwemilo okubangelwa kuxinzelelo lobushushu Ukuguquka okubangelwa kuxinzelelo lobushushu kwenzeka kwiindawo ezinobushushu obuphezulu apho amandla okuvelisa amacandelo entsimbi aphantsi, i-plasticity iphezulu, umphezulu uphola ngokukhawuleza, kwaye umahluko wobushushu phakathi kwangaphakathi nangaphandle kwesixhobo somsebenzi ngowona mkhulu. Ngeli xesha, uxinzelelo lobushushu olukhawulezileyo luxinzelelo lokuqina komphezulu kunye noxinzelelo lo ...
Ukuguquka kwemilo okubangelwa kuxinzelelo lwezicubu Ukuguquka okubangelwa kuxinzelelo lwezicubu kwenzeka kwangoko xa uxinzelelo lwezicubu luphezulu. Ngeli xesha, umahluko wobushushu obuphakathi kwecandelo mkhulu, ubushushu obuphakathi buphezulu, busekwimeko ye-austenite, i-plasticity ilungile, kwaye amandla okuvelisa aphantsi. Uxinzelelo lwezicubu olukhawulezileyo luxinzelelo lokucinezela umphezulu kunye noxinzelelo lokuxinana kwezicubu. Ke ngoko, ukuguquka kubonakaliswa njengokwandiswa kwentloko phantsi kwesenzo soxinzelelo lokuxinana oluneendlela ezininzi. Isiphumo kukuba phantsi kwesenzo soxinzelelo lwezicubu, icala elikhulu lomsebenzi liyanwebeka, ngelixa icala elincinci lifinyela. Umzekelo, ukuguquka okubangelwa kuxinzelelo lwezicubu kwisilinda ende kukwandiswa kobude kunye nokunciphisa ububanzi.
Itheyibhile 5.3 ibonisa imithetho yokucima ukuguquka kwezixhobo ezahlukeneyo zentsimbi.
2) Izinto ezichaphazela ukuguquka kokucima
Izinto ezichaphazela ukuguquka kokucima ikakhulu ziikhemikhali ezikwintsimbi, ulwakhiwo lwazo lokuqala, ijiyometri yeendawo kunye nenkqubo yokunyanga ubushushu.
3) Ukucima imifantu
Ukuqhekeka kwiindawo ezithile kwenzeka kakhulu kwinqanaba lokugqibela lokucinywa nokuphola, oko kukuthi, emva kokuba utshintsho lwe-martensitic lugqityiwe okanye emva kokuphola ngokupheleleyo, ukungaphumeleli kokuqhekeka kwenzeka kuba uxinzelelo lokuxinana kwiindawo ludlula amandla okuqhekeka kwentsimbi. Ukuqhekeka kudla ngokuba ngqo kwicala lokuguquguquka okuphezulu kokuxinana, ngoko ke iintlobo ezahlukeneyo zokuqhekeka kwiindawo ezithile zixhomekeke kakhulu kwimeko yokusasazwa koxinzelelo.
Iintlobo eziqhelekileyo zokuqhekeka kokucima: Ukuqhekeka kwe-longitudinal (axial) kwenziwa ikakhulu xa uxinzelelo lokuxinana kwe-tangential ludlula amandla okuqhekeka kwezinto; ukuqhekeka okunqamlezileyo kwenziwa xa uxinzelelo olukhulu lokuxinana kwe-axial olwenziwe kumphezulu wangaphakathi wenxalenye ludlula amandla okuqhekeka kwezinto. Ukuqhekeka; ukuqhekeka kwenethiwekhi kwenziwa phantsi kwesenzo soxinzelelo lokuxinana olunemilinganiselo emibini kumphezulu; ukuqhekeka okuqhekekayo kwenzeka kumaleko oqinileyo kakhulu, okunokwenzeka xa uxinzelelo lutshintsha ngokukhawuleza kwaye uxinzelelo lokuxinana olugqithisileyo lusebenza kwicala le-radial. Uhlobo lokuqhekeka.
Iimfantu ezinde zikwabizwa ngokuba ziimfantu ezijikelezayo. Iimfantu zenzeka ngoxinzelelo olukhulu lokuxinana kufutshane nomphezulu wenxalenye, kwaye zinobunzulu obuthile embindini. Icala leemfantu ngokubanzi lihambelana ne-axis, kodwa icala linokutshintsha xa kukho uxinzelelo oluphezulu kwinxalenye okanye xa kukho iziphene zangaphakathi zesakhiwo.
Emva kokuba umsebenzi ucinyiwe ngokupheleleyo, imifantu emide inokwenzeka. Oku kunxulumene noxinzelelo olukhulu lokuxinana kwe-tangential kumphezulu wesixhobo somsebenzi esicinyiweyo. Njengoko umxholo wekhabhoni wentsimbi usanda, ukuthambekela kokwenza imifantu emide kuyanda. Intsimbi yekhabhoni ephantsi inomthamo omncinci we-martensite kunye noxinzelelo olunamandla lobushushu. Kukho uxinzelelo olukhulu lokuxinana olushiyekileyo kumphezulu, ngoko ke akulula ukulucima. Njengoko umxholo wekhabhoni usanda, uxinzelelo lokuxinana komphezulu luyancipha kwaye uxinzelelo lolwakhiwo luyanda. Kwangaxeshanye, uxinzelelo lokuxinana oluphezulu luya kutsho kumaleko womphezulu. Ke ngoko, intsimbi yekhabhoni ephezulu isenokuba nemifantu emide xa ishushu kakhulu.
Ubungakanani bamacandelo buchaphazela ngokuthe ngqo ubungakanani kunye nokusasazwa koxinzelelo olushiyekileyo, kwaye utyekelo lwalo lokuqhekeka kokucima nalo lwahlukile. Iimfanta ezinde nazo zenziwa ngokulula ngokucinywa ngaphakathi koluhlu lobukhulu obunobungozi obunqamlezileyo. Ukongeza, ukuvaleka kwezinto eziluhlaza zentsimbi kudla ngokubangela iimfanta ezinde. Ekubeni uninzi lwamacandelo entsimbi enziwa ngokuqengqeleka, iimfanta ezingezizo zegolide, iikhabhayithi, njl. kwintsimbi zisasazwa kwicala lokuguqulwa, nto leyo ebangela ukuba intsimbi ibe yi-anisotropic. Umzekelo, ukuba intsimbi yesixhobo inesakhiwo esifana nebhendi, amandla ayo okuqhekeka emva kokucima angaphantsi ngama-30% ukuya kuma-50% kunamandla okuqhekeka okude. Ukuba kukho izinto ezifana neemfanta ezingezizo zegolide kwintsimbi ezibangela uxinzelelo loxinzelelo, nokuba uxinzelelo lwe-tangential lukhulu kunoxinzelelo lwe-axial, iimfanta ezinde kulula ukuzenza phantsi kweemeko zoxinzelelo oluphantsi. Ngenxa yesi sizathu, ulawulo oluqinileyo lwenqanaba leemfanta ezingezizo zesinyithi kunye neswekile kwintsimbi yinto ebalulekileyo ekuthinteleni ukucima iimfanta.
Iimpawu zokusasazwa koxinzelelo lwangaphakathi lwee-cross cracks kunye nee-arc cracks zezi: umphezulu uphantsi koxinzelelo oluxinzelelweyo. Emva kokushiya umphezulu umgama othile, uxinzelelo oluxinzelelweyo luyatshintsha lube luxinzelelo olukhulu lokuxinana. Ukuqhekeka kwenzeka kwindawo yoxinzelelo lokuxinana, kwaye emva koko xa uxinzelelo lwangaphakathi lusasazeka kumphezulu wenxalenye kuphela ukuba isasazwa kwakhona okanye ukuqhekeka kwentsimbi kuyanda ngakumbi.
Iimfantu ezinqamlezileyo zihlala zenzeka kwiindawo ezinkulu ze-shaft, ezifana nee-roller, ii-turbine rotors okanye ezinye iindawo ze-shaft. Iimpawu zezimfantu kukuba zithe nkqo kwicala le-axis kwaye ziyaqhekeka ukusuka ngaphakathi ukuya ngaphandle. Zihlala zenzeka ngaphambi kokuba ziqine kwaye zibangelwa luxinzelelo lobushushu. Ii-forgings ezinkulu zihlala zineziphene ze-metallurgical ezifana nee-pores, i-inclusions, iimfantu zokubumba kunye namabala amhlophe. Ezi ziphene zisebenza njengendawo yokuqala yokuqhekeka kunye nokuqhekeka phantsi kwesenzo soxinzelelo lokuxinana kwe-axial. Iimfantu ze-arc zibangelwa luxinzelelo lobushushu kwaye zihlala zisasazwa ngesimo se-arc kwiindawo apho imo yenxalenye itshintsha khona. Iyenzeka kakhulu ngaphakathi kwendawo yokusebenza okanye kufutshane nemiphetho ebukhali, imingxunya kunye nemingxunya, kwaye isasazwa ngesimo se-arc. Xa iindawo zentsimbi ezinekhabhoni ephezulu enobubanzi okanye ubukhulu obuyi-80 ukuya kwi-100 mm nangaphezulu zingacinywanga, umphezulu uya kubonisa uxinzelelo lokuxinana kwaye iziko liya kubonisa uxinzelelo lokuxinana. Uxinzelelo, uxinzelelo oluphezulu lokuxinana lwenzeka kwindawo yokutshintsha ukusuka kumaleko oqinileyo ukuya kumaleko ongelukhuni, kwaye iimfantu ze-arc zenzeka kwezi ndawo. Ukongeza, izinga lokupholisa kwiikona ezibukhali likhawuleza kwaye zonke ziyacinywa. Xa utshintshela kwiindawo ezithambileyo, oko kukuthi, kwindawo engaqinanga, indawo ephezulu yoxinzelelo lokuxinana ibonakala apha, ngoko ke ukuqhekeka kwe-arc kuyenzeka. Izinga lokupholisa kufutshane nomngxuma wephini, umngxuma okanye umngxuma osembindini wesixhobo somsebenzi licotha, umaleko oqinanga ohambelanayo ubhityile, kwaye uxinzelelo lokuxinana kufutshane nendawo yotshintsho oluqinanga lunokubangela ukuqhekeka kwe-arc ngokulula.
Iimfantu ezihlala ecaleni, ezaziwa ngokuba ziimfantu ezisemantla, ziimfantu ezisemantla. Ubunzulu bemfantu abunzulu kangako, ngokubanzi bumalunga ne-0.01 ~ 1.5mm. Uphawu oluphambili lolu hlobo lwemfantu kukuba indlela engaqondakaliyo yemfantu ayinanto yakwenza nokuma kwenxalenye. Iimfantu ezininzi ziqhagamshelwe omnye komnye ukuze zenze inethiwekhi kwaye zisasazeke ngokubanzi. Xa ubunzulu bemfantu bukhulu, obufana ne-1 mm, iimpawu zenethiwekhi ziyanyamalala kwaye zibe ziimfantu ezijolise ngokungacwangciswanga okanye ezisasazeke ngokude. Iimfantu zenethiwekhi zinxulumene nemeko yoxinzelelo lokuxinana olunemilinganiselo emibini kumphezulu.
Iindawo zentsimbi ezinekhabhoni eninzi okanye ezinekhabhoni ezifakwe umaleko osuswe kwikhabhoni phezu komhlaba zidla ngokwenza imifantu yenethiwekhi ngexesha lokucima. Oku kungenxa yokuba umaleko womphezulu unomxholo ophantsi wekhabhoni kunye nomthamo omncinci othile kunomaleko wangaphakathi we-martensite. Ngexesha lokucima, umaleko womphezulu wekhabhoni uphantsi koxinzelelo lokuxinana. Iindawo ezinomaleko we-dephosphorization ongasuswanga ngokupheleleyo ngexesha lokucubungula oomatshini nazo ziya kwenza imifantu yenethiwekhi ngexesha lokucima umphezulu welangatye oqhelekileyo okanye ilangatye. Ukuze kuthintelwe imifantu enjalo, umgangatho womphezulu weendawo kufuneka ulawulwe ngokungqongqo, kwaye ukuwelda kwe-oxidation kufuneka kuthintelwe ngexesha lonyango lobushushu. Ukongeza, emva kokuba i-forging die isetyenzisiwe ixesha elithile, imifantu yokudinwa kobushushu ebonakala kwimigca okanye kwiinethiwekhi kwi-cavity kunye nemifantu kwinkqubo yokugaya iindawo ezicinyiweyo zonke zezo zilolu hlobo.
Ukuqhekeka kwenzeka kwindawo emxinwa kakhulu yomaleko womphezulu. Uxinzelelo oluxinzelelweyo lusebenza kwicala le-axial kunye ne-tangential, kwaye uxinzelelo lokuxinana luyenzeka kwicala le-radial. Ukuqhekeka kuyafana nomphezulu wenxalenye. Ukuqhekeka komaleko oqinisiweyo emva kokuba iindawo zokucinywa komphezulu kunye ne-carburizing zipholisiwe zezo ziqhekeko. Ukwenzeka kwayo kunxulumene nesakhiwo esingalinganiyo kumaleko oqinisiweyo. Umzekelo, emva kokuba intsimbi ye-alloy carburised ipholisiwe ngesantya esithile, isakhiwo kumaleko we-carburised si: umaleko wangaphandle we-pearlite entle kakhulu + carbide, kwaye i-sublayer yi-martensite + i-Austenite eseleyo, umaleko wangaphakathi yi-pearlite entle kakhulu okanye isakhiwo se-pearlite esihle kakhulu. Ekubeni umthamo othile wokwakheka kwe-martensite yomaleko ongaphantsi yeyona inkulu, isiphumo sokwandiswa komthamo kukuba uxinzelelo oluxinzelelweyo lusebenza kumaleko womphezulu kumacala e-axial kunye ne-tangential, kwaye uxinzelelo lokuxinana luyenzeka kwicala le-radial, kwaye utshintsho loxinzelelo luyenzeka ngaphakathi, luguqukela kwimeko yoxinzelelo oluxinzelelweyo, kwaye ukuqhekeka kwemifantu Kwenzeka kwiindawo ezincinci kakhulu apho utshintsho loxinzelelo lujika ngokukhawuleza. Ngokubanzi, iintanda zifihlakele ngaphakathi ngokulandelelana nomphezulu, kwaye kwiimeko ezinzima zinokubangela ukuxobuka komphezulu. Ukuba izinga lokupholisa leenxalenye ze-carburing liyakhawuleza okanye liyancitshiswa, isakhiwo se-martensite esifanayo okanye isakhiwo se-pearlite esincinci kakhulu sinokufunyanwa kumaleko we-carburing, nto leyo enokuthintela ukwenzeka kwezi ntanda. Ukongeza, ngexesha lokucima umphezulu welangatye onamaza amaninzi okanye ilangatye, umphezulu uhlala ushushu kakhulu kwaye ukungalingani kwesakhiwo kumaleko oqinileyo kunokwenza ngokulula ezo ntanda kumphezulu.
Ii-Microcracks zahlukile kwii-cracks ezine ezikhankanyiweyo apha ngasentla kuba zibangelwa yi-microstress. Ii-cracks eziphakathi kweegranular ezibonakala emva kokucima, ukutshisa kakhulu kunye nokusila intsimbi yesixhobo esinekhabhoni ephezulu okanye izinto zokusebenza ezine-carburized, kunye nee-cracks ezibangelwa kukungafudunyezwa ngexesha elifanelekileyo kweendawo ezicinyiweyo, zonke zinxulumene nokubakho kunye nokwandiswa okulandelayo kwee-microcracks kwintsimbi.
Iimicrocracks kufuneka zihlolwe phantsi kwe-microscope. Zihlala zenzeka kwimida yokuqala yeenkozo ze-austenite okanye ekudibaneni kwamaphepha e-martensite. Ezinye ii-cracks zingena kwii-martensite sheets. Uphando lubonisa ukuba ii-microcracks zixhaphake kakhulu kwi-martensite ene-flaky twinned. Isizathu kukuba i-martensite ene-flaky iyangqubana xa ikhula ngesantya esiphezulu kwaye ivelisa uxinzelelo oluphezulu. Nangona kunjalo, i-martensite ene-twinned ngokwayo ibuthathaka kwaye ayinakuvelisa i-plastic deformation ikhulula uxinzelelo, ngaloo ndlela ibangela ii-microcracks ngokulula. Ii-austenite grains zirhabaxa kwaye ukuthambekela kwi-microcracks kuyanda. Ubukho bee-microcracks kwintsimbi kuya kunciphisa kakhulu amandla kunye ne-plasticity yeendawo ezicinyiweyo, okukhokelela ekonakaleni kwangoko (ukuqhekeka) kweendawo.
Ukuze kuthintelwe ukuqhekeka kwee-microcracks kwiindawo zentsimbi ezinekhabhoni ephezulu, amanyathelo anjengokunciphisa ubushushu bokufudumeza, ukufumana isakhiwo se-martensite esicocekileyo, kunye nokunciphisa umxholo wekhabhoni kwi-martensite angasetyenziswa. Ukongeza, ukufudumeza ngexesha elifanelekileyo emva kokurhoxisa yindlela esebenzayo yokunciphisa uxinzelelo lwangaphakathi. Uvavanyo luye lwabonisa ukuba emva kokufudumeza ngokwaneleyo ngaphezulu kwama-200°C, ii-carbides ezifakwe kwiimfanta zinefuthe "lokushibiliza" iimfanta, nto leyo enokunciphisa kakhulu iingozi zeemfanta.
Oku kungasentla yingxoxo ngezizathu kunye neendlela zokuthintela iintanda ngokusekelwe kwipateni yokusasazwa kweentanda. Kwimveliso yokwenyani, ukusasazwa kweentanda kuyahluka ngenxa yezinto ezifana nomgangatho wentsimbi, ukuma kwenxalenye, kunye netekhnoloji yokucubungula eshushu nebandayo. Ngamanye amaxesha iintanda sele zikhona ngaphambi konyango lobushushu kwaye zanda ngakumbi ngexesha lenkqubo yokucima; ngamanye amaxesha iintlobo ezininzi zeentanda zinokuvela kwindawo enye ngaxeshanye. Kule meko, ngokusekelwe kwiimpawu zemo yentanda, uhlalutyo lwe-macroscopic lomphezulu wokuqhekeka, uvavanyo lwe-metallographic, kwaye xa kuyimfuneko, uhlalutyo lweekhemikhali kunye nezinye iindlela kufuneka zisetyenziswe ukwenza uhlalutyo olupheleleyo ukusuka kumgangatho wezinto, ulwakhiwo lwentlangano ukuya kwizizathu zoxinzelelo lonyango lobushushu ukufumana iintanda. izizathu eziphambili kwaye emva koko kuchongwe amanyathelo okuthintela asebenzayo.
Uhlalutyo lokwaphuka kweentanda yindlela ebalulekileyo yokuhlalutya izizathu zokuqhekeka. Naluphi na ukwaphuka lunendawo yokuqala yokuqhekeka. Ukucima iintanda kudla ngokuqala kwindawo yokuhlangana kweentanda zeradial.
Ukuba imvelaphi yekroba ikhona kumphezulu wenxalenye, oko kuthetha ukuba ikroba libangelwa kukuxinana okugqithisileyo kumphezulu. Ukuba akukho ziphene zesakhiwo ezifana nokuqukwa kumphezulu, kodwa kukho izinto ezibangela uxinzelelo ezifana neempawu zemela ezinzima, isikali se-oxide, iikona ezibukhali zeendawo zentsimbi, okanye iindawo zokuguquka kwesakhiwo, ukuqhekeka kunokwenzeka.
Ukuba imvelaphi yekroba ingaphakathi kwenxalenye, inxulumene neziphene zezinto okanye uxinzelelo olugqithisileyo lokuxinana kwangaphakathi. Umphezulu wokuqhekeka wokucinywa okuqhelekileyo ungwevu kwaye ucolekile ngeporcelain. Ukuba umphezulu wokuqhekeka ungwevu omnyama kwaye urhabaxa, ubangelwa kukushisa kakhulu okanye izicubu zokuqala zityebile.
Ngokubanzi, akufuneki kubekho mbala we-oxidation kwicandelo leglasi le-crying crack, kwaye akufuneki kubekho i-decarburization ejikeleze i-crack. Ukuba kukho i-decarburization ejikeleze i-crack okanye umbala we-oxidized kwicandelo le-crack, oko kubonisa ukuba inxalenye sele inee-cracks ngaphambi kokuba i-clock, kwaye ii-cracks zokuqala ziya kwanda phantsi kwempembelelo yoxinzelelo lonyango lobushushu. Ukuba ii-carbides ezahlulwe kunye ne-inclusions zibonwa kufutshane nee-cracks zenxalenye, oko kuthetha ukuba ii-cracks zinxulumene nokwahlulwa okukhulu kwee-carbides kwizinto eziluhlaza okanye ukubakho kwee-inclusions. Ukuba ii-cracks zivela kuphela kwiikona ezibukhali okanye kwiindawo zokuguqulwa kwemilo zenxalenye ngaphandle kwesi siganeko singasentla, oko kuthetha ukuba i-crack ibangelwa kuyilo olungenangqiqo lwesakhiwo senxalenye okanye amanyathelo angafanelekanga okuthintela ii-cracks, okanye uxinzelelo olugqithisileyo lonyango lobushushu.
Ukongeza, iintanda kwiindawo zonyango lobushushu beekhemikhali kunye nezokucima umphezulu zibonakala kakhulu kufutshane nomaleko oqinileyo. Ukuphucula ulwakhiwo lomaleko oqinileyo kunye nokunciphisa uxinzelelo lonyango lobushushu ziindlela ezibalulekileyo zokuthintela iintanda kumphezulu.
Ixesha leposi: Meyi-22-2024