Utshintsho kwi-microstructure kunye neepropathi ze-forging ngexesha lokufudumala

Forgingsemva kokucima, i-martensite kunye nokugcinwa kwe-austenite ayizinzile, banombutho ozenzekelayo wenguqu kwimo yozinzo, njengekhabhoni ye-supersaturated kwi-martensite ukukhupha i-austenite eyintsalela yokubola ukuze kukhuthazwe inguqu, efana nokucaphuka ngumbutho ongekho ukulingana. ukulungelelanisa iinkqubo zombutho, le nkqubo ixhomekeke kwimfuduko yeathom kunye nokusasazwa kolu gunyaziso kunye nobushushu obugqityiweyo bomlilo buphezulu, isantya sosasazo olukhawulezayo; Ngokuchasene noko, kunye nokwanda kweqondo lobushushu, ukucima ukwakhiwa kwe-forgings. jongana nothotho lotshintsho. Ngokwemeko yenguqu ye-microstructure, i-temperature yahlulahlulwe ngokubanzi ngokwezigaba ezine: ukubola kwe-martensite, ukubola kwe-austenite okushiyekileyo, ukukhula kokuqokelela kwe-carbide kunye ne-ferrite recrystallization.
Inqanaba lokuqala (200)
(1) ukwenzaI-martensite evuthayo ibolile phantsi kwe-80 yokushisa ubushushu, ukucima intsimbi ngaphandle kokuguqulwa kwe-Ming S umbutho, ukwenzeka kwekhabhoni kwi-martensite kuphela inxalenye, kwaye akukho qalisa ukudiliza kwi-80-200 tempering, i-martensite iqala ukubola, iyancipha i-carbides ecashile kakhulu, ukunciphisa iqhezu lobunzima be-martensite kwi-carbon forgings kweli nqanaba, ngenxa yobushushu obuphantsi, imvula ye-martensitic kuphela inxalenye ye-athom ye-carbon ephezulu, ngoko ke iseyikhabhoni kwi- - Fe supersaturated isisombululo esiqinileyoImvula ye-carbide ecolekileyo kakhulu isasazeke ngokufanayo kwi-matrix. ye martensite. Isakhiwo esixubeneyo sokugcwala okuphantsi kweMartensite kunye ne-carbide entle kakhulu ibizwa ngokuba yi- tempered Martensite.

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(2)ukwenzaukuphola kwinqanaba lesibini (200-300), intsalela austenite ukubola xa ubushushu benyuka ukuya 200-300, ukubola martensite waqhubeka, kodwa utshintsho olubalaseleyo yi residual austenite ukubola intsalela austenite ukubola kwaba ngokusebenzisa ukwandiswa athom carbon. ukwenza indawo eyinxenye, kwaye emva koko iboliswe ibe yinqanaba le-alpha kunye nomxube wentlangano ye-carbide, oko kukuthi ukubunjwa kobulukhuni bentsimbi ye-bainite ayinciphi ngokucacileyo kweli nqanaba.
(3)Inqanaba lesithathu (250-400) inguqu ye-carbide ye-forging tempering ikuloluhlu lobushushu. Ngenxa yobushushu obuphezulu, amandla okusasazwa kweCarbon atom yomelele, amandla okusasaza ukubuyisela iiathom zentsimbi kwakhona, i-martensite ibolisa inguqu ye-carbides yemvula kunye nokubola okushiyekileyo kwe-austenite kuya kujikwa ibe yi-cementite ezinzileyo kunye nokwahlula kunye nokuguqulwa kwee-carbides, ukuncipha. of martensite in carbon mass iqhezu, martensite ilettice ukugqwetheka shwaka, inguqu martensitic for ferrite, ukufumana ferritic matrix ukusasazwa ngaphakathi granular okanye lamellar cementite encinane yombutho, umbutho ebizwa tempering ngokusisiseko yapheliswa esi sigaba austenite ukucima uxinzelelo, ubulukhuni, ukuqina plasticity kwaphuculwa.

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(4)Inqanaba lesine lokufudumeza (& GT;400) likhule i-carbide iqokelelwe kwaye iphinda ihlaziywe kwakhona ye-ferrite ngenxa yobushushu bobushushu buphezulu kakhulu, i-carbon kunye nee-athom zentsimbi zinamandla okukhula, isigaba sesithathu sokwenziwa kweeflakes ze-cementite ziya kuqhubeka zi-spheroidizing kwaye zikhule. phezulu ngaphezu kwe-500-600, i-alpha recrystallization yenzeka ngokuthe ngcembe, ilahlekelwe yi-ferrite morphology yomgca wepleyiti yokuqala okanye ishidi, kwaye yenze ukuhanjiswa kweenkozo zepolygon kumbutho njenge-ferritic matrix granular carbides, iqela elibizwa ngokuba yi tempering sorbite tempered sorbite enomatshini olungileyo obanzi. iipropati zesigaba kunye ne-lattice ukuphazamiseka kuphelisa uxinzelelo lwangaphakathi.

(ukusuka kwi-168 yokwenza umnatha)


Ixesha lokuposa: Aug-05-2020

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