Ungazikhiqiza kanjani izingxenye zensimbi ezisezingeni eliphezulu ze-chromium?

Insimbi ephezulu ye-chromium iyinto ebaluleke kakhulu engagqoki esetshenziswa kabanzi ezimbonini ezifana ne-metallurgy, izimayini, usimende, namandla. Izinqubo zayo zokwelashwa kokuncibilika nokushisa zidinga izidingo eziqinile zokuqinisekisa ukuthola i-microstructure ekahle kanye nokumelana nokugqokwa okuhle kakhulu.

Okulandelayo incazelo eningiliziwe yamaphuzu abalulekile ezithako ezincibilikayo, izinga lokushisa elincibilikayo, izinga lokushisa elithelayo, kanye nenqubo yokwelapha ukushisa kwensimbi ephonswe nge-chromium ephezulu.

1, Ukwakheka kwamakhemikhali ensimbi encibilikisiwe ye-chromium ephezulu kuyisisekelo sokusebenza kwayo, ngokuvamile nge-Cr/C (i-chromium carbon ratio) njengento ewumgogodla womklamo.

1. Ibanga lokwakheka kwamakhemikhali abalulekile (okujwayelekile): Ikhabhoni (C): 2.0% -3.5%. Okuqukethwe kwekhabhoni kunquma inani, i-morphology, nobulukhuni be-carbides eyinhloko kanye ne-eutectic carbides. Ukuphakama kwekhabhoni, kuyanda ubulukhuni, kodwa ukuqina kuyehla. I-Chromium (Cr): 12% -30% (ivame ukutholakala ku-15% -28%). I-Chromium iyisici esibalulekile sokwenza ama-carbides nokuqinisekisa ukumelana nokugqwala kwe-substrate. Iphuzu elibalulekile ukulawula isilinganiso se-Cr/C. I-Molybdenum (Mo): 0.5% -3.0%. I-Molybdenum ingathuthukisa ukuqina, ivimbele ukuguqulwa kwe-pearlite, futhi ikhuthaze ukwakheka kwe-bainite noma i-martensite, ikakhulukazi ekulingiseni kwesigaba esikhulu. Ngesikhathi esifanayo, ingakwazi ukulungisa inhlangano, ithuthukise ukuqina nokumelana nokugqoka. Ithusi (Cu): 0.5% -1.5%. Iphinde isetshenziselwe ukuthuthukisa ukuqina futhi ithatha indawo ye-molybdenum engabizi kancane, kodwa umphumela wayo awumuhle njenge-molybdenum. I-Nickel (Ni): 0-1.5%. Siza ekuthuthukiseni ukuqina nokuqinisa i-matrix. I-Manganese (Mn): 0.5% -1.0%. Zinzisa i-austenite futhi uthuthukise ukuqina. Kodwa-ke, amazinga aphezulu kakhulu angakwazi ukuzinza i-austenite, okuholela ekwandeni kwe-austenite esele kanye nokuhlukaniswa emingceleni yokusanhlamvu, okulimaza ukuqina. I-Silicon (Si): 0.3% -1.0%. Izakhi ze-Deoxidizing, kodwa zizothuthukisa i-carbide graphitization, ngakho okuqukethwe akufanele kube phezulu kakhulu. I-Sulfur (S) ne-phosphorus (P): Inqunyelwe ngokuqinile. P <0.06%，S <0.05%。 Zonke ziyizinto eziyingozi ezinganciphisa kakhulu ukuqina namandla, futhi zikhulise ukuthambekela kokuqhekeka okushisayo.

2. Ukubaluleka kwesilinganiso se-Cr/C: Cr/C<4: (Fe, Cr) ∝ C carbides izovela esakhiweni, enobulukhuni obuphansi kanye nokungagugi kahle. I-Cr/C ≈ 4-10: ubulukhuni obuphezulu (Fe, Cr) ₇ C ∨ eutectic carbide (okuwumthombo oyinhloko wokumelana nokugqokwa kwe-chromium cast iron ephezulu) yakheka ngendlela yenduku noma i-strip, enomthelela omncane wokuhlukanisa ku-matrix kanye nokuqina okungcono. Lesi isikhawu esisetshenziswa kakhulu. Cr/C>10: Inani elikhulu lika-(Cr, Fe) ₂ ∝ C ₆ - uhlobo lwe-carbides luqala ukwakheka. Nakuba ukumelana nokugqwala kuthuthukisiwe, ubulukhuni buyancipha futhi ukumelana nokugqoka akukuhle njenge (Fe, Cr) ₇ C ₆.

3. Ukubalwa kwesithako: Bala isilinganiso sokushajwa kwesithando somlilo ngokusekelwe esithakweni esiqondiwe kanye nezinga lokuthola kabusha. Ishaja yesithando somlilo ngokuvamile yakhiwa insimbi yengulube, insimbi eyizinsimbi, i-chromium iron (njenge-carbon chromium iron ephezulu, i-carbon chromium iron ephansi), insimbi ye-molybdenum, ithusi, ipuleti le-nickel, njll. Ireferensi yesilinganiso sokutakula: Izinto ezifana no-Cr no-Mo zinezinga eliphezulu lokutakula uma zincibilika ku-medium frequency, 5% induction noboya ngokuvamile obungu-9%. Izinga lokululama likaMn lilinganiselwa ku-85% -95%.

2. Izinga lokushisa elincibilikayo kanye nezinga lokushisa elithelayo

1. Izinga lokushisa lokuncibilika: Izinga lokushisa lokuncibilika akufanele libe phezulu kakhulu, ngokuvamile lilawulwa phakathi kuka-1480 ° C no-1520 ° C. Isizathu: Izinga lokushisa elidlulele lingakhuphula ukulahlekelwa okushisayo kwezakhi ze-alloy (njenge-Cr ne-Si oxidation), kuqinise ukumuncwa kwe-hydrogen ne-nitrogen oketshezini lwensimbi, futhi kwenze izinhlamvu zibe matsheke. Izinga lokushisa eliphansi alihambisani nokuncibilika kwe-alloy, ukwakheka kwe-homogenization, nokuhlukaniswa kwe-slag iron.

2. Ukushisa okuthululwayo: Ukushisa okuthululwayo kufanele kunqunywe ngokuvumelana nobukhulu bodonga kanye nesakhiwo sokubunjwa, ngokuvamile kusukela ku-1380 ° C kuya ku-1450 ° C. Ezingxenyeni eziwugqinsi nezilula, izinga lokushisa eliphansi lokuthulula (elifana ne-1380 ° C kuya ku-1420 ° C) kufanele lisetshenziswe ukwenza lula ukuqiniswa okulandelanayo, ukunciphisa usayizi wokusanhlamvu, nokunciphisa usayizi wokusanhlamvu. Izingxenye ezinodonga ezizacile neziyinkimbinkimbi: Sebenzisa amazinga okushisa aphezulu okuthela (afana no-1420 ° C-1450 ° C) ukuze uqinisekise ikhono elihle lokugcwalisa. Isimiso: Ngaphansi kwesisekelo sokuqinisekisa ukugcwaliswa, zama ukusebenzisa izinga lokushisa eliphansi lokuthulula ngangokunokwenzeka.

3. Amaphuzu abalulekile enqubo yokwelapha ukushisa

I-ascast microstructure yensimbi ephezulu ye-chromium imvamisa i-austenite+eutectic carbides+i-pearlite eyingxenye, enobulukhuni obuphansi kanye nokuqina okubi. I-matrix ye-martensitic enobulukhuni obuphezulu nokumelana nokugqoka ingatholakala kuphela ngokwelashwa kokushisa.

Umnyombo wokwelapha ukushisa "i-austenitization+quenching".

1. I-Austenitizing: Izinga lokushisa: 940 ° C-980 ° C. Izinga lokushisa elithile lincike ekwakhiweni, ikakhulukazi okuqukethwe kwe-Cr no-C. Ukuze uthole amafomula ekhabhoni ephezulu kanye ne-chromium ephezulu, thatha umkhawulo wokushisa ophansi, ngaphandle kwalokho thatha umkhawulo wokushisa ophezulu. Isikhathi sokushisisa: Ngokujwayelekile sibalwa ngokusekelwe kugqinsi lwezindonga, ukwahlukanisa kuthatha ihora elingu-1 kuwo wonke amamilimitha angama-25. Qinisekisa ukuthi i-carbon nezakhi ze-alloying kuma-carbides zincibilika ngokuphelele ku-austenite, kodwa isikhathi eside singaholela ekukhuleni okusanhlamvu kanye nokugwaza kwe-carbide. Iphuzu elingukhiye: Ngemuva kwe-austenitization, i-matrix iba yi-austenite ecebile nge-carbon ne-alloying elements.

2. Ukucisha: Indlela yokupholisa: Ngemva kokususwa emazingeni okushisa e-austenitizing, kufanele zipholiswe ngokushesha (kucinywe). Indlela evamile: Ukucisha Umoya: Lena indlela evame ukusetshenziswa futhi ephephile. Ngenxa yokuqukethwe kwayo okuphezulu kwe-alloy nokuqina okuhle, ukupholisa komoya kwanele ukugwema ukuguqulwa kwe-pearlite nokuthola i-matrix ye-martensitic. Ezingxenyeni ezinkulu noma eziyinkimbinkimbi, ukupholisa umoya kunganciphisa ngempumelelo ingozi yokuqhekeka. Ukucisha Umoya Okuphoqelekile: ukusebenzisa isiphephetha-moya ukuphefumula umoya nokusheshisa ukupholisa. Ukucisha uwoyela: Kusetshenziselwa kuphela ukulingisa okuncane kakhulu noma okulula, okunobungozi obukhulu kanye nokuqhekeka okulula, okudinga ukuqapha okukhulu. Injongo: Ukupholisa izinga lokushisa eliphezulu kwe-austenite ngaphansi kwezinga lokushisa lokuguqulwa kwe-martensitic (uMs iphuzu) futhi uyiguqule ibe yi-martensite yokuqina okuphezulu.

3. Ukushisa: Isidingo: Ngemva kokucisha, ingcindezi yangaphakathi iphezulu kakhulu, futhi isakhiwo siyi-martensite+residual austenite, eshwabene kakhulu futhi kufanele ifutheke ngokushesha. Izinga lokushisa: Izinga lokushisa eliphansi livame ukusetshenziswa phakathi kuka-200 ° C no-300 ° C, futhi ngezinye izikhathi izinga lokushisa eliphakathi nendawo elizungeze u-450 ° C liyasetshenziswa (okunciphisa ubulukhuni kodwa kuthuthukisa ukuqina). Isikhathi sokufakelwa: amahora angama-2-6 (kuya ngokuqina kodonga). Umsebenzi: Yehlisa ingcindezi eqeda amandla futhi uvimbele ukuqhekeka ngesikhathi sokusetshenziswa. Ukuguqula i-martensite ecishiwe ibe i-martensite epholile kunciphisa ubulukhuni, kodwa kuthuthukisa kakhulu ukuqina nokuzinza. Thuthukisa ukuguqulwa kwe-austenite esele ibe yi-martensite (ukucima okwesibili).

4. Inqubo ekhethekile: Ukwelashwa okungaphansi. Kwezinye izimo zokusebenza ezidinga ukuqina komthelela omkhulu, ukwelashwa okungaphansi kokufakwa kwesikhathi eside (njengamahora angu-4-10) phakathi kuka-450 ° C-520 ° C kungasetshenziswa. Le nqubo ibola i-austenite eyinsalela ibe yi-bainite ferrite nama-carbides, okuholela ekuhlanganiseni okuhle kakhulu kwamandla nokuqina, kodwa ubulukhuni bungancipha.

Isifinyezo: Ijika elijwayelekile lokwelapha ukushisa kwe-KmTBCr26 high chromium cast iron limi kanje: [Austenitization] Ukushisa ku-960 ° C ± 10 ° C ->Ukubamba amahora angu-4-6 ->[Ukucisha] Ukupholisa komoya ekamelweni lokushisa ->[Tempering] Ishisisa ngokushesha ukuya ku-±-250 ° C amahora angu-250 ° C -> Ukupholisa komoya ngemva kokukhishwa. Isikhumbuzi esibalulekile: Ngaphambi kokungena esithandweni sokushisa ukushisa, ama-castings kufanele ahlanzwe kahle (ukukhipha isihlabathi esibumbayo, izikhuphukeli, njll.). Izinga lokushisa akufanele lisheshe kakhulu, ikakhulukazi ezingxenyeni eziyinkimbinkimbi. Kunconywa ukushisa isinyathelo ngesinyathelo (njengokugcina izinga lokushisa elifanayo lika-600 ° C isikhathi esithile). Ngemuva kokushisa, kufanele ipholile ekamelweni lokushisa ngaphambi kokusetshenziswa. Kuphela ngokulawula kahle ukwakheka, ukuncibilika, kanye nochungechunge lwemingcele yokwelapha ukushisa lapho izingxenye ezisebenza kahle kakhulu ze-chromium cast iron iron zingakhiqizwa.