Ungavelisa njani iindawo zentsimbi ekhahlelelweyo ekumgangatho ophezulu wechromium?

Intsimbi ephezulu yechromium yeyona nto ibaluleke kakhulu ukumelana nokunxitywa esetyenziswa kakhulu kumashishini afana nesinyithi, imigodi, isamente, kunye namandla. Ukunyibilika kwayo kunye neenkqubo zonyango lobushushu zifuna iimfuno ezingqongqo zokuqinisekisa ukufumana i-microstructure efanelekileyo kunye nokumelana nokunxiba okugqwesileyo.

Oku kulandelayo yinkcazo eneenkcukacha yamanqaku aphambili okunyibilika kwezithako, ubushushu obunyibilikayo, ubushushu obuthululwayo, kunye nenkqubo yonyango lobushushu kwintsimbi ephezulu yechromium.

I-1, Ukwakhiwa kweekhemikhali zentsimbi enyibilikisiweyo ephezulu yechromium sisiseko sokusebenza kwayo, ngokuqhelekileyo kunye ne-Cr / C (i-chromium carbon ratio) njengento yoyilo oluphambili.

1. Uluhlu lweekhemikhali ezingundoqo (eziqhelekileyo): I-Carbon (C): 2.0% -3.5%. Umxholo wekhabhoni umisela ubuninzi, i-morphology, kunye nobunzima bee-carbides eziphambili kunye ne-eutectic carbides. Ukuphakama komxholo wekhabhoni, ukuphakama kobunzima, kodwa ukuqina kuncipha. I-Chromium (Cr): 12% -30% (ngokuqhelekileyo ifumaneka kwi-15% -28%). I-Chromium yinto ephambili yokwenza i-carbides kunye nokuqinisekisa ukuxhathisa kwe-corrosion ye-substrate. Inqaku eliphambili kukulawula umlinganiselo weCr/C. I-Molybdenum (Mo): 0.5% -3.0%. I-Molybdenum inokuphucula ukuqina, inqanda ukuguqulwa kwe-pearlite, kwaye ikhuthaze ukubunjwa kwe-bainite okanye i-martensite, ngokukodwa kwi-casting yecandelo elikhulu. Ngexesha elifanayo, inokuphucula umbutho, iphucule ukuqina kunye nokugqoka ukuchasana. Ubhedu (Cu): 0.5% -1.5%. Ikwasetyenziselwa ukuphucula ukuqina kwaye ithatha indawo ye-molybdenum engabiziyo, kodwa isiphumo sayo asilungile njenge-molybdenum. Nickel (Ni): 0-1.5%. Ukuncedisa ekuphuculeni ukuqina kunye nokomeleza i-matrix. IManganese (Mn): 0.5% -1.0%. Zinzise i-austenite kwaye uphucule ukuqina. Nangona kunjalo, amanqanaba aphezulu kakhulu anokuzinzisa i-austenite, ekhokelela ekwandeni kwe-austenite eseleyo kunye nokwahlula kwimida yengqolowa, eyonakalisa ukuqina. I-Silicon (Si): 0.3% -1.0%. Izinto ze-Deoxidizing, kodwa ziya kukhuthaza i-carbide graphitization, ngoko umxholo akufanele ube phezulu kakhulu. Isulfure (S) kunye nephosphorus (P): Inqongophele ngokungqongqo. P <0.06%，S <0.05%。 Zizo zonke izinto ezinobungozi ezinokunciphisa kakhulu ubunzima kunye namandla, kwaye zandise ukuthambekela kokuqhekeka kwe-thermal.

2. Ukubaluleka kwe-Cr / C ratio: Cr / C <4: (Fe, Cr) ∝ I-carbides ye-C iya kubonakala kwisakhiwo, ngobunzima obuphantsi kunye nokuxhatshazwa okungahambi kakuhle. I-Cr / C ≈ 4-10: ubunzima obuphezulu (Fe, Cr) ₇ C ∨ i-eutectic carbide (eyona nto ingumthombo oyintloko wokunganyangeki kwentsimbi ephezulu ye-chromium) yenziwe ngendlela yentonga okanye i-strip, enefuthe elincinci lokwahlula kwi-matrix kunye nobunzima obungcono. Eli lelona khefu lisetyenziswa kakhulu. Cr/C>10: Isixa esikhulu se (Cr, Fe) ₂ ∝ C ₆ - uhlobo lwe-carbides luqala ukwenza. Nangona ukuxhathisa kwe-corrosion kuphuculwe, ubunzima buyancipha kwaye ukuxhathisa ukunxiba akulunganga njenge (Fe, Cr) ₇ C ₆.

3. Ukubalwa kwesithako: Bala umlinganiselo wentlawulo yesithando somlilo ngokusekelwe kwisithako esijoliswe kuyo kunye nesantya sokubuyisela. Intlawulo yeziko idla ngokuqulunqwa ngentsimbi yehagu, intsimbi yentsimbi, intsimbi yechromium (efana nentsimbi ye-carbon chromium, intsimbi ephantsi ye-carbon chromium), intsimbi ye-molybdenum, ubhedu, ipleyiti ye-nickel, njl. Izinga lokubuyiswa kwe-Mn malunga ne-85% -95%.

2, Ubushushu obunyibilikayo kunye nobushushu obugalelayo

1. Ubushushu bokunyibilikisa: Ubushushu bokucofa akufanele bube phezulu kakhulu, ngokuqhelekileyo bulawulwa phakathi kwe-1480 ° C kunye ne-1520 ° C. Isizathu: Ukushisa okugqithisileyo kunokunyusa ilahleko evuthayo yezinto ze-alloy (ezifana ne-Cr kunye ne-Si oxidation), ukuqinisa ukufunxwa kwe-hydrogen kunye ne-nitrogen kulwelo lwentsimbi, kwaye wenze iinkozo zibe rhabaxa. Iqondo lokushisa eliphantsi alihambisani ne-alloy melting, i-homogenization yokubunjwa, kunye nokuhlukana kwentsimbi ye-slag.

2. Ukushisa okuthululwayo: Ukushisa okuthululwayo kufuneka kumiselwe ngokobunzima bodonga kunye nesakhiwo sokuphosa, ngokuqhelekileyo ukusuka kwi-1380 ° C ukuya kwi-1450 ° C. Kwiindawo ezityebileyo nezilula, iqondo lokushisa eliphantsi lokuthulula (elifana ne-1380 ° C ukuya kwi-1420 ° C) kufuneka lisetyenziswe ukuququzelela ukuqiniswa okulandelelanayo, ukunciphisa ubungakanani bengqolowa, kunye nokunciphisa ubungakanani bengqolowa. Iindawo ezibhityileyo ezinodonga nezintsonkothileyo: Sebenzisa amaqondo obushushu okugalela aphezulu (afana ne-1420 ° C-1450 ° C) ukuqinisekisa ukukwazi ukuzalisa okulungileyo. Umgaqo: Ngaphantsi kwesiseko sokuqinisekisa ukuzaliswa, zama ukusebenzisa ubushushu obuphantsi bokuthulula kangangoko kunokwenzeka.

3, Amanqaku aphambili enkqubo yokunyanga ubushushu

I-microstructure njenge-cast cast yentsimbi ephezulu ye-chromium idla ngokuba yi-austenite+eutectic carbides+ipearlite eyingxenye, enobulukhuni obuphantsi kunye nokuqina okulambathayo. I-matrix ye-martensitic enobunzima obuphezulu kunye nokumelana nokunxiba inokufumaneka kuphela ngonyango lobushushu.

Undoqo wonyango lobushushu "yi-austenitization + quenching".

1. I-Austenitizing: Ubushushu: 940 ° C-980 ° C. Ubushushu obuthile buxhomekeke ekubunjweni, ngokukodwa umxholo weCr kunye noC. Kwikhabhoni ephezulu kunye neefomyula eziphezulu ze-chromium, thatha umda weqondo lokushisa eliphantsi, ngaphandle koko thabatha umda ophezulu wokushisa. Ixesha lokufakwa kwe-insulation: Ngokuqhelekileyo kubalwa ngokusekelwe kubukhulu bodonga, ukugquma kuthatha iyure eli-1 kuzo zonke iimilimitha ezingama-25. Qinisekisa ukuba i-carbon kunye ne-alloying element kwi-carbides zichithwa ngokupheleleyo kwi-austenite, kodwa ixesha elide linokukhokelela ekukhuleni kweenkozo kunye ne-carbide coarsening. Inqaku eliphambili: Emva kwe-austenitization, i-matrix iba yi-austenite ecebileyo kwikhabhoni kunye nezinto ezixutywayo.

2. Ukucima: Indlela yokupholisa: Emva kokususwa kwiqondo lokushisa le-austenitizing, kufuneka lipholiswe ngokukhawuleza (licinywe). Indlela eqhelekileyo: Ukucima Umoya: Le yeyona ndlela isetyenziswa ngokuqhelekileyo kwaye ikhuselekile. Ngenxa yomxholo we-alloy ephezulu kunye nokuqina okulungileyo, ukupholisa umoya kwanele ukuphepha ukuguqulwa kwepearlite kunye nokufumana i-matrix ye-martensitic. Kumacandelo amakhulu okanye anzima, ukupholisa umoya kunokunciphisa ngokufanelekileyo umngcipheko wokuqhekeka. Ukucinywa koMoya ngenkani: ukusebenzisa ifeni ukuvuthela umoya kunye nokukhawulezisa ukupholisa. Ukucima i-oyile: Isetyenziselwa kuphela ukuphosa okuncinci kakhulu okanye okulula okumile, kunye nomngcipheko omkhulu kunye nokuqhekeka okulula, kufuna ukuqaphela okukhulu. Injongo: Ukuthoba ubushushu obuphezulu austenite ngaphantsi kobushushu benguqu ye-martensitic (Ms point) kwaye uyiguqule ibe yi-martensite ephezulu yokuqina.

3. Ukufudumala: Imfuneko: Emva kokucima, uxinzelelo lwangaphakathi luphezulu kakhulu, kwaye isakhiwo yi-martensite +residual austenite eseleyo, enqabileyo kakhulu kwaye kufuneka iphonswe ngokukhawuleza. Ubushushu: Ubushushu obuphantsi buqhele ukusetyenziswa phakathi kwe-200 ° C kunye ne-300 ° C, kwaye ngamanye amaxesha ubushushu obuphakathi obuphakathi kwama-450 ° C bukwasetyenziswa (okunciphisa ubulukhuni kodwa buphucule ukuqina). Ixesha le-Insulation: iiyure ezingama-2-6 (kuxhomekeke kubukhulu bodonga). Umsebenzi: Ukuphelisa uxinzelelo kunye nokuthintela ukuqhekeka ngexesha lokusetyenziswa. Ukuguqula i-martensite ecinyiweyo ibe yi-martensite epholileyo kunciphisa kancinci ubulukhuni, kodwa kuphucula kakhulu ukuqina kunye nokuzinza. Ukukhuthaza ukuguqulwa kwe-austenite eshiyekileyo ibe yi-martensite (ukucima okwesibini).

4. Inkqubo ekhethekileyo: Unyango olungaphantsi. Kwezinye iimeko zokusebenza ezifuna ukuqina kwempembelelo ephezulu, unyango lwe-subcritical kunye nokufakwa kwexesha elide (ezifana neeyure ze-4-10) phakathi kwe-450 ° C-520 ° C zingasetyenziswa. Le nkqubo ibolisa i-austenite eshiyekileyo ibe yi-bainite ferrite kunye ne-carbides, okukhokelela kwindibaniselwano egqwesileyo yamandla kunye nokuqina, kodwa ukuqina kunokuncipha.

Isishwankathelo: Igophe eliqhelekileyo lonyango lobushushu leKmTBCr26 intsimbi ephezulu yechromium ilandelayo: [Austenitization] Ukufudumeza ukuya kwi-960 ° C ± 10 ° C ->Ukubamba iiyure ezi-4-6 ->[Ukucima] Ukupholisa umoya kwiqondo lobushushu begumbi ->[Ubushushu] Ukufudumeza kwangoko ukuya kwi-±-40 ° C kwiiyure ezingama-210 ° C. -> Ukupholisa umoya emva kokuphuma. Isikhumbuzi esibalulekileyo: Ngaphambi kokungena kwisithando somlilo kunyango lokufudumala, i-castings kufuneka ihlambuluke ngokucokisekileyo (ukususa isanti yokubumba, ukunyuka, njl.). Izinga lokufudumeza akufanele likhawuleze, ngakumbi kumacandelo anzima. Kunconywa ukutshisa inyathelo ngesinyathelo (njengokugcina ubushushu obufanayo be-600 ° C ixesha elithile). Emva kokufudumala, kufuneka ipholiswe kwiqondo lokushisa ngaphambi kokusetyenziswa. Kuphela ngokulawula ngokuchanekileyo ukubunjwa, ukunyibilika, kunye nothotho lweeparamitha zonyango lobushushu ezinokuvelisa iindawo eziphezulu ze-chromium yentsimbi ekhatywayo ekwaziyo ukunxiba.