PSI - Issue 16

Yevstakhiy Kryzhanivskyy et al. / Procedia Structural Integrity 16 (2019) 237–244 Yevstakhiy Kryzhanivskyy et al. / Structural Integrity Procedia 00 (2019) 000 – 000

241

5

80

70

60

50

А р /А , %

40

1

30

2

3

20

10

-60

- 40

-20

0

20

t, o C

Fig. 3. Effect of test temperature on (А р /А) values: 1 – base metal (BM); 2 – fusion zone (W1); 3 – fusion zone (W2).

3.3. Zones of fracture surface

It is known that the process of impact deformation and fracture of Charpy specimens includes the stages of intense localization of deformation and fracture (zones I, II and III, IV), which alternate successively, Fig. 4.

20 o C

0 o C

-20 o C

-40 o C

-60 o C

BM

Fusion zone (W1)

Fusion zone (W2)

Fig. 4. Optical images of fracture surfaces of Charpy specimens: base metal (BM); fusion zone (W1); fusion zone (W2) for the temperature range from - 60 °C to 20 °C .

Each fracture zone has a characteristic size (area). The dimensions of the zone are traces of fracture, which allow estimating the effective energy intensity of fracture in the first approximation. At the same time, it is practically impossible to clearly divide (in time and energy) the formation of the zone of growth of the crack and shear lips. That is, although they occur at different parts of the specimen, they still occur in adjacent zones and practically