Specific Features of Structural-Phase State and Properties of Reactor Pressure Vessel Steel at Elevated Irradiation Temperature

Table 5

The summary results of mechanical tests and structural study of 15Kh2NMFAA steel specimens: as-received, after segregation provoking treatment, and after irradiation at 300°C and 400°C.

State

, MPa

, °С

Carbides and carbonitrides

, % of monolayer coverage

η, %

Precipitates

Dislocation loops

Me7C3

Me(C, N)

(Cr, Mo)2C

ρ, 10^23m^−3

, nm

ρ, 10^21m^−3

, nm

, nm

ρ, 10^19m^−3

, nm

ρ, 10^21m^−3

, nm

ρ, 10^20m^−3

As-received

—

—

80–100

8 ± 2

14-15

2.9 ± 0.5

35–45

2.5 ± 0.6

—

0

0

—

0

—

Segregation provoking treatment

35

70–150

7.2 ± 1.5

14-15

3.1 ± 0.5

40–50

2.3 ± 0.5

14

30

0

—

0

—

Irradiation at 300°С

52

46

80–100

7 ± 2

13-14

3.5 ± 0.5

35–45

3.0 ± 0.2

2

0

1.4 ± 0.2

2.5 ± 0.5

2.5 ± 0.8

5 ± 2

Irradiation at 400°C

10

17

80–120

5.2 ± 1.0

8-9

6.8 ± 1.0

30–50

2.1 ± 0.5

6

5

0

—

0

—

: the difference between the mean value of phosphorus concentration in the as-received and the current state, expressed in % of monolayer coverage. : the change in the yield strength; : the shift of the critical brittleness temperature; , ρ: the size and number density of different hardening structural elements.