PSI - Issue 65

A.V. Sulitsin et al. / Procedia Structural Integrity 65 (2024) 282–289 A.V. Sulitsin, , S.V. Brusnitsyn, D.O. Levin, D.A. Usov, V.K. Dubrovin / Structural Integrity Procedia 00 (2024) 000–000 7

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Ingots with a diameter of 200 mm were cast on a semi-continuous casting unit. The casting temperature was 1160…1180 ºС, the casting speed was 3.5 m/h. Ni-Mg-Ce ligature was added to the melt in a quantity of 0.06 wt. %. Samples were cut from the ingots for metallographic analysis. The microstructure of ingots is shown in Fig. 6.

a

b

Fig. 6. The Microstructure of ingots of complex-alloyed brass 70Cu-13Zn-7Mn-5Al-2Fe-2Si-1Pb: without modification (a); with addition of modifier (b).

It was found that when adding a modifier to the melt, the average area of intermetallics in the alloy structure is 361 μm 2 , which is almost two times less than the average area of intermetallics in the alloy structure without adding a modifier to the melt, which is 676 μm 2 . Thus, modifying complex-alloyed brass 70Cu-13Zn-7Mn-5Al-2Fe-2Si 1Pb with Ni-Mg-Ce ligature in a quantity of 0.06 wt. % ensures effective grinding of intermetallics and eliminates the formation of their conglomerates.

3. Conclusion

1. Modification of complex-alloyed brass 70Cu-13Zn-7Mn-5Al-2Fe-2Si-1Pb with mischmetal, magnesium cerium ligature, and niobium ensured a significant decrease in the average size of needle-shaped intermetallics and a decrease in the volume fraction of the α-phase. It was found that the greatest effect was achieved with the addition of magnesium-cerium ligature, with the modification of which there were no intermetallics clusters in the brass structure, the average size of which did not exceed 80 μm. 2. It has been established that modification of complex-alloyed brass 70Cu-13Zn-7Mn-5Al-2Fe-2Si-1Pb with Ni Mg-Ce ligature is an effective way of refining the structure and leveling the mechanical properties along the ingot cross-section. Thus, using Ni-Mg-Ce ligature as a modifier allows reducing the average grain size by more than two times and the average area of intermetallics by almost two times. In addition, the HRB hardness increases from 85 to 92 and the tensile strength and elongation along the ingot cross-section are leveled. 3. It has been shown that the rational amount of Ni-Mg-Ce ligature for modifying brass 70Cu-13Zn-7Mn-5Al 2Fe-2Si-1Pb is 0.04...0.06 wt. %. 4. The use of Ni-Mg-Ce ligature as a modifier allows for the utilization of small fractions of waste generated during its production.

References

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