Caractéristiques organisationnelles ya 42 CRMO bague Billet Figure 1 ezali simulation numérique informatique ya tissu solidifié na coulée centrifuge verticale na vitesse ya coulée ya 480 rad/s, température ya coulée ya 1500 degrés , diamètre extérieur ya coulée ya 1000mm, diamètre interne ya 360mm mpe ba paramètres ya procédés ya cassé. Figure 4. Ndenge ekoki komonana na figure, mur ya libanda ya casting annulaire ezali région cristalline isopacique fine uniforme. Na kati ya casting, mbuma ebongwanaka uta na cristal isopaxial ya malamu kino na etuka ya cristal ya makonzí ya monene, mpe cristal ya makonzí ezali kokóma monene mpe monene. This is due to the alloy in the process of centrifugal casting solidification, when the metal liquid into the casting, the cooling of the wall, start knot, crystal solidification, crystalline latent heat is perpendicular to the cast wall continuous outward heat dissipation, so the metal to the setting in the solidification of centrifugal casting process, because the casting wall is cold, and the cast wall is cold, but water spraying, when high temperature metal meets low temperature casting Mur, pene na mur ya métal na effet ya refroidissement makasi, ebimisaka degré ya surfroidissement makasi mpe nombre monene ya noyau hétérogène. Ba noyau oyo na froid fondue na croissance ya Dendite, en raison ya dissipation ya chaleur ya cristallisation sans directionnel, mpe ebele ya, noyau e bloquer moko na mosusu ekoba kokola, donc pene ya zone ya mur ya coulée circulaire esala petite, axiale organisation ya cristal, na augmentation ya épaisseur ya solidification mpe formation ya coquille solidification stable, grain directement, na surface ya axial cristal ya grain. Due to the coagulation layer barrier cooling, the alloy liquid cooling speed is reduced, resulting in lower alloy solidification speed, centrifugal casting process alloy liquid is mainly controlled by the one-dimensional cooling temperature, at this time, one-way heat dissipation conditions at the solid-liquid interface, under the action of one-way heat flow, the alloy along the radial ring casting growth, thus formed in Figure 1 (b) area column. Na ntina na bokoli ya kopona, na bokoli ya cristal ya makonzí, soki ntaka oyo ezali mosika na efelo ezali mosika, ba cristaux oyo ezali malamu te elongolami, ekosila, soki cristal ya makonzí ezali na boyokani mingi, mpe soki bonene ya mbuma ezali monene, ndenge emonisami na elilingi 1 (c).
3 Ba raisons ya séparation macroscopique 3.1 Na tango ya solidification ya coulée centrifuge, liquide ya métal rotatif ezali soumis na force centrifuge radiale mpe verticale, mpe gravité droite en bas. Force centrifuge ezali proportionnelle na rayon ya rotation, mpe proportionnel na carré ya vitesse ya rotation angulaire:
F ezali mosika na M2R .
esika: F ezali nguya ya centrifuge ya mai ya ebende; M ezali masse ya liquide ya métal; Ezali vitesse angulaire rotative ya cast. Lokola na accélération ya gravité na champ gravitationnel, liquide ya métal ekozala na accélération centrifuge na champ de force centrifuge rotative.3.2 séparation ya composition pona coulée centrifuge ya 42 CRMO bague casting, redistribution ya ba atome ya solute ekosalema na température ya solidification pe na phase ya solide ya solide pe na phase solide. Na yango, ememaka na mbongwana makasi na kati ya biloko oyo esalemi na alliage. En fonction ya équation ya séparation macroscopique P, vitesse moyenne ya débit ya alliage na vitesse ya refroidissement na yango ya solidification ezali bias macroscopique .
u 1
Analyse nde e jouaka rôle ya munene. Tango résultat na yango ezali 1, segregation te. Na tina ya effet ya force centrifuge, vitesse ya débit na yango ezo accélérer, tango vitesse ya débit ya liquide ya alliage v. Contrairement na direction ya vitesse ya solidification U, liquide ezo bima na suka ya moto ya région ya deux phases tii na suka ya malili, elingi koloba, na débit interne na mosisa ya misisa ya solute zone riche, mpe ebimisi segregation négative, na ndenge mosusu, na ndenge mosusu. Na boyekoli oyo, na bopusi ya ba éléments ya alliage, chrome ezali na affinité makasi na carbone, oyo ekitisaka vitesse ya diffusion ya carbone, ematisaka période ya incubation ya décomposition austenite superfreidie, mpe ekitisaka vitesse ya solidification, na ndenge wana ko générer séparation.3.3 Layer Segregation Figure 4 schéma schématique ya section asquelimatique. Tango mayi ya alliage na kati ya cast, liquide ya métal na forme ya débit ya débit axial, mouvement, à savoir couche ya liboso ya liquide ya métal 1 esala débit axial, en raison ya réduction ya température, vitesse ya débit, petite, vitesse ya flux ya liboso ② débit mpe koleka débit ya liboso, écoulement, mpe bongo na bongo, en raison ya ba conditions ya solidification na température, vitesse, vitesse, vitesse, vitesse, vitesse, vitesse ya tissu.
3.4 Ba mesures ya kokitisa bopanzani Ba mesures ya kokitisa bopanzani ya macro ezali : 1 Pona vitesse ya coulée oyo ebongi, po liquide ya alliage ezala na .
Vitesse ya débit oyo ebongi.Bakisa agent ya incubation na processus ya solidification ya liquide ya alliage pona ko accélérer solidification.3 Zua méthode ya refroidissement oyo ebongi pona ko réduire temps ya solidification ya zone ya deux phases solide-liquide, pe komatisaka temps ya refroidissement ya solidification na ndenge ekoki.
Caractéristiques ya tissus na macro-séanalyse ya CU-17NI-3AL-X alliage casting ya CU-17NI-3AL-X ya cuivre na diamètre ya cercle ya libanda ya 265mm, épaisseur ya soki 50mm mpe hauteur ya 125mm esalemaki na méthode ya coulée centrifuge. Ba caractéristiques tissulaires mpe macro-segration ya casting ya alliage ya cuivre e étudier na métallographie mpe na sonde électronique. Ba résultats ezo lakisa que ezali na ba formes mibale ya cristal isoaxial na cristal cylindrique na casting, oyo ekabolami na mur ya libanda pe mur ya kati ya casting, pe ekabolami na centre ya casting na esika oyo ezali pene ya mur ya kati ya casting. In the main combination, the gold elements Cu, Ni, and Al showed slight macroscopic segregation along the radial and axial directions of the casting, but were still within the design range of the alloy.2 Test Results 2.1 Tissue characteristics of the Casting The typical macroscopic tissue characteristics of the casting are shown in Figure 2. It can be seen from the figure that the macroscopic tissue morphology of the casting is symmetrical along the casting; Organisation macroscopique ya casting ekoki kokabolama na ba zones minei oyo ezali évidemment différentes : zone isoaxiale finale ya mur ya libanda ya casting (2, parallèlement na casting (id, zone isoaxiale grossière (II) pene ya mur ya kati ya casting, IV pene ya suka na mur ya kati ya casting).
Ntina ezali ete koleka ya melt ya bibende mpe kokabola lisusu ba atome ya solute esalaka te mbongwana ya makasi na kati ya composition ya alliage. En fonction ya formule discriminante ya séparation macroscopique, ba conditions ya kosilisa séparation macroscopique ezali :
v / u / ( 1)
Tango alliage ezuami, vitesse moyenne ya écoulement liquide na dendrite mpe vitesse ya solidification ya alliage e déterminer u. Mpo na alliage solidifié mpe contractée, tango vitesse moyenne ya écoulement liquide na dendrite mpe vitesse ya solidification ya alliage ezali na direction opposée, moyenne ya vitesse moyenne ya écoulement liquide mpe plus, plus ezali malamu ko réduire séparation macroscopique. Na tango ya casting centrifuge, vitesse ya écoulement ya force centrifuge mpe force coridienne ezo accélérer mingi, oyo ezali défavorable mpo na ko inhiber séparation macroscopique. Kasi, na boyekoli oyo, lokola ba composants ya minene ezali cuivre mpe nickel, bokeseni na yango ya densité na fondue ezali moke mpenza, en plus, refroidissement ya mayi ya casting centrifuge, ekoki ko refiner efficacement dendrite, kobongisa vitesse ya solidification ya alliage, surtout mpo épaisseur ya mur ya blank ya casting (pene na 55mm), ekoki ko inhiber efficacement débit ya fondue, mpo na ko réduire to ko réduire to ko réduire but ya macroscogrégration.
En fonction ya ba exigences ya RCC-M, matériel ya pipeline principale ya île nucléaire ya Centrale nucléaire ya réacteur ya mayi ya réacteur ya réacteur CPR1000 ezali acier inoxydable austénite (marque française Z3CN20-09M). Momekano oyo emoni ete motuya ya ebende ya pipeline ya monene engebene na biteni ya shevler ya MC1000 (Schaeffler) mpe biteni ya MC1340, mpe etalelaki bantina ya bokeseni ya mbano ya bomonisi ya mayele ndenge na ndenge. Na kotalaka expérience ya fabrication ya pipeline principale pe contenus ya RCC-MM3406, ba raisons ya distribution ya bomati ya teneur ya fer ya pipeline e analysé. Bolai ya bosaleli ya lolenge ya kotala teneur ya ferrite pe MC1340, botalisi ya teneur ya ferrite, pe lolenge ya kosilisa bopanzani ya ferrite oyo ezali ndenge moko te na canal principal ezali na bokuse.
Inconvénient ya casting centrifuge ezali liquide ya métal rotatif sous action ya force centrifuge, densité élevée ya ba éléments, organisation ezali na tendance ya munene na mur (surface ya libanda ya dépôt centrifuge), mpe densité, élément mpe organisation ya moke ezali na tendance ya munene mpo na ko migrer na surface intérieure, phénomène oyo ebengami centrimenugugale, external ekozala na centrimenugique ya externe. Bokabwani, lokola tube principal centrifuge austénite casting inoxydable, carbone, azote, phosphore mpe ba éléments ya soufre mpo na ko flotter na surface ya kati ya tube centrifuge, mpe ba éléments ya densité makasi na surface ya libanda ya tube centrifuge. Combined with the material of the centrifugal tube in RCC-M Z3CN20-09M austenite one ferrite stainless steel, including carbon, nitrogen, phosphorus, sulfur and other elements density is far lower than that of iron, pouring metal steel in casting hollow cooling process (natural cooling), by the centrifugal force to the inner wall migration, so that carbon, nitrogen, phosphorus, sulfur and other elements Na komonana ya bomati ya likolo ya kati.Bituluku mibale ya ba échantillons ya test eponami na Tableau 2, mpe ba déterminer teneur ya azote na nzela ya méthode spectroscopique. Ba résultats elakisami na Tableau 3, mpe inférence oyo ezali likolo endimami lisusu.
Ekoki komonana na métallographie mpe na diagramme ya Schevler mpe na diagramme ya delong oyo euti na yango ete carbone mpe azote ezali ba éléments oyo ezali na bopusi mingi oyo ezali kolendisa formation to stabilisation ya austénite. Na diagramme ya délong, carbone na azote na élément ya formule ya calcul équivalent ya nickel ezali 30%. It is concluded that the increase of ferrite content in the centrifugal tube from the inner wall to the outer wall is the increase of carbon and nitrogen from the outer surface to the inner surface and the internal floating and sedimentation of the centrifugal tube casting.2.3 Control of centrifugal casting components In industrial production, centrifugal casting components is often used to manufacture castings with gradient properties, such as metal composite castings na résistance ya kolata ya likolo na surface ya kati. En plus, après centrifuge casting, mayi spray ya refroidissement rapide (tube ya centrifuge ya mayi) centrifuge tuyau ezali moke koleka tube ya coulément centrifuge ya refroidissement ya mopepe, mpe distribution ya fer ezali relativement uniforme. MP30 Ferrite Tester esalelamaki mpo na koyeba motuya ya ebende na 1 / 4 ya likolo ya kati, 1 / 2 mpe 1 / 4 ya likolo ya libanda ya unité Yangjiang 1. Point ya détection elakisami na figure 6, pe ba résultats elakisami na tableau 4. Selon le tableau 4, mayi ya kosopela mayi ya refroidissement ya mbangu ezuami sima ya coulée centrifuge, sans distribution ya fer oyo ezali komata ya polele uta na mur ya mayi ya kati tii na mur ya libanda. Na analyse ya composition mpe na contrôle ya four ya tube centrifuge principal, en plus ya kokutana na teneur ya ferrite ya RCC-MM3406 évalué na shevler-diagramme, azote mpe ba éléments résiduels mosusu esengeli mpe ezala contrôlé. Lokola densité ya azote mpe ya carbone ezali mosika na nse koleka fer, yango ezalaka na tendance ya kokende na mur ya kati ya tube ya centrifugeuse, oyo ememaka na segregation ya teneur ya ferrite mpo na segregation ya ba composants. Méthode ya ko contrôler composition na séparation tissulaire ya tube ya centrifugeuse en acier inoxydable austénite-ferrite ezali centrifugation refroivée na mayi. En même temps, casting centrifuge ebimisaka caractéristique ya séparation ya composition, oyo ekoki kobimisa ba produits spéciaux na ba castings na ba exigences ya performance.
