PSI - Issue 50

A.S. Smirnov et al. / Procedia Structural Integrity 50 (2023) 266–274 A.S. Smirnov, A.V. Konovalov,V.S. Kanakin and I.A. Spirina / Structural Integrity Procedia 00 (2022) 000 – 000

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stress and the volume portion of the dynamic recrystallization in the heterogenized V95 alloy with strain rates ranging from 0.01 to 5 s − 1 at a temperature of 400  C. Figure 5 shows the strain and strain rate dependences of the volume portion of dynamic recrystallization r V and flow stress  , which are obtained according to model (1). It can be concluded from these dependences that, at a temperature of 400 °C in the V95 alloy, with increasing the strain rate, the heterogeneity of the grain microstructure increases due to an increase in the rate of dynamic recrystallization. This causes a change in the shape of the flow stress curve. As can be seen from Fig. 5b, at strain rates below 0.05 s − 1 there is no peak value in the curves, and at strain rates above 0.5 s − 1 there are pronounced peaks of stress in the curves.

Table 1. Flow stress model coefficients 0 a 1 a 2 a 3 a 4 a

5 a

6 a

7 a

8 a

9 a

10 a

11 a

12 a

13 a

14 a

23

180467

0.04

71

5.0

0.886

0.0319

0.0149

16

82.8

0.243

0.003

1.75

0.186

0.015

Fig. 3. The specimen microstructure before (a) and after deformation of the V95 alloy at 400  C according to dependencies 1 (b), 2 (c), and 3 (d). Dependencies 1 to 3 are shown in Fig. 4a.