Rezumat

Piesele turnate sunt produse printr-o metodă de fabricație care împreună cu selecția aliajului și tratarea topiturii afectează în mod inerent proprietățile microstructurale generale ale componentei, inclusiv defectele. Indiferent dacă materialele feroase sau neferoase sunt folosite pentru o aplicație curentă, există proiectarea componentelor, incluzând canalul de rulare, ascensoare și porți, metalurgie și relații de proces, ceea ce duce la componente care conțin o mare varietate de microstructuri, inclusiv dimensiunea, morfologia și distribuția defectelor și, prin urmare, o varietate de proprietăți pe întreaga geometrie. Grosimea peretelui influențează macrogranulația microstructurii, iar componenta va avea proprietăți în funcție de istoriile metalurgice și termice locale. Mai mult, poate acumula tensiuni reziduale în timpul răcirii, care la rândul lor afectează comportamentul la deformare a componentelor turnate. Având în vedere acest lucru, este evident că, pentru a îndeplini cerințele de configurare privind performanța, în general, este nevoie de compromisuri pentru a găsi un echilibru între mai multe obiective conflictuale. Adesea, simulările mecanice ale situațiilor de încărcare se bazează pe ipoteza că produsul turnat are proprietăți materiale constante pe toată durata turnării. Realitatea diferă și, prin urmare, proiectanții sunt încurajați să țină cont de faptul că proprietățile care provin din bara de testare standardizată ar putea duce probabil la supradimensionare neeconomică, rezultate necorespunzătoare și concluzii în majoritatea cazurilor. 

Castings are produced by a manufacturing method that together with alloy selection and melt treatment inherently affect the component’s overall microstructural properties including defects. Whether ferrous or nonferrous materials are employed for a current application, design of components including runner, riser and gating, metallurgy, and process relations are existing, which lead to components containing a wide variety of microstructures including defect size, morphology, and distribution and hence a variety of properties over the entire geometry. The wall thickness influences the coarseness of the microstructure, and the component will have properties depending on the local metallurgical and thermal histories. Moreover, it can build up residual stresses during cooling which in turn affects the deformation behavior of cast components. With this in mind, it is obvious that in order to meet setup demands on performance generally requires compromises to strike a balance between several conflicting objectives. Often, mechanical simulations of the load situations are based on the assumption that the cast product has constant material properties throughout the entire casting. Reality differs and therefore designers are encouraged to bear in mind that properties that originate from standardized test bar might probably lead to uneconomic over-dimensioning, improper results, and conclusions in most cases.

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