Influence of germanium and the melting method on the mechanical properties of NM23KhYu alloy at high temperatures

Conclusions

• 1. Alloying with germanium of NM23KhYu alloy leads to a two to three times increase in its impact strength at test temperatures of 900–1200°C.

• 2. Electron beam remelting of NM23KhYu alloy with germanium increases the impact strength at test temperatures of 800–1200°C by two or three times and the characteristics of plasticity (δ and ψ) at 1100–1200°C by 1.5–2 times in comparison with the similar properties of this alloy produced by vacuum induction melting.

• 3. Torsion tests did not reveal differences in the plastic properties of the electron beam remelted and the vacuum induction alloys in the 1100–1250°C temperature interval. Reliability in prediction of the optimum production plasticity is provided by the analysis of the results of composite investigations — tension, impact strength, torsion, and metallographic.

• 4. It is recommended that hot working by pressure of NM23KhYu alloy with germanium be done at a temperature of 1180⁻²⁰°C.