TY - BOOK
T1 - Reliability of reactor materials program
T2 - Semiannual progress report for period ending June 30, 1981
AU - Törrönen, Kari
PY - 1982
Y1 - 1982
N2 - This is the first semiannual progress report for the
Reliability of Reactor Materials Program, funded by the
Ministry of Trade and Industry in Finland and the
Technical Research Centre of Finland.
In the area of quality technology the activity was
started with a study of defects characterization by
ultrasonic pulse-echo spectroscopy. Other techniques will
be used in connection with the international
PlSC-program.
In the area of fracture mechanics work has been done to
develop a modern computer interactive testing system for
the fracture toughness evaluation of metallic materials.
Also, a program for comparing computational and
experimental elastic-plastic results was started. The
testing system utilizes the unloading compliance single
specimen method to develop crack growth resistance curves
based on the J-integral concept and determines the
relevant material parameters. By the end of the reporting
period the testing of CT-type
specimens became possible.
Comparisons between computational and experimental
elastic-plastic results are made using four different
materials and four specimen geometries. A two-dimensional
elastic-plastic code is used for the computational
analysis.
Preliminary irradiations for mechanisms and annealing
studies have been conducted and nondestructive
evaluations using the Barkhausen noise analysis and
hardness tests have been initiated. Further irradiation
for the evaluation of J-R curve characteristics of a weld
material will be started in the near future.
Long term thermal ageing studies have been continued.
Accelerated annealings at 450°C for one year do not
introduce any shift in the Charpy V transition
temperature of SA 533B base material and only a slight
increase was evident in the case of the corresponding
weld material.
In the area of environment sensitive cracking long term
stress corrosion cracking studies of different austenitic
stainless steels have been concluded and reported.
Comparable studies concerning the ferritic pressure
vessel and piping materials have been initiated. The
first corrosion fatigue tests in the recently
commissioned autoclave system have been completed
successfully.
Mechanistic studies of environment sensitive cracking in
pressure vessel steels have been continued and a
hydrogen-induced cracking model based on extensive
fractography has been outlined.
Corrosion studies have been concentrated on oxidation and
decontamination of austeniti; stainless steels in both
PWR and BWR conditions. In the area of low temperature
sensitisation studies long term annealings of different
stainless steel weld materials have been continued.
A sub-project has been initiated to generate basic
knowledge of the thermal fatigue behaviour of the
materials used in nuclear power planes. During this
reporting period a brief review of the problem areas has
been compiled.
In the area of repair welding the microstructural and
hardness studies revelled that the half bead repair
welding method man have some advantages compared try
normal manual arc welding. The differences are, however,
rather small and there exists a large scatter. The
microstructural studies of the HAZ reveal that a perfect
tempering effect is very difficult to obtain in halt bead
repair welding due to the wavelike shape of the fusion
line.
AB - This is the first semiannual progress report for the
Reliability of Reactor Materials Program, funded by the
Ministry of Trade and Industry in Finland and the
Technical Research Centre of Finland.
In the area of quality technology the activity was
started with a study of defects characterization by
ultrasonic pulse-echo spectroscopy. Other techniques will
be used in connection with the international
PlSC-program.
In the area of fracture mechanics work has been done to
develop a modern computer interactive testing system for
the fracture toughness evaluation of metallic materials.
Also, a program for comparing computational and
experimental elastic-plastic results was started. The
testing system utilizes the unloading compliance single
specimen method to develop crack growth resistance curves
based on the J-integral concept and determines the
relevant material parameters. By the end of the reporting
period the testing of CT-type
specimens became possible.
Comparisons between computational and experimental
elastic-plastic results are made using four different
materials and four specimen geometries. A two-dimensional
elastic-plastic code is used for the computational
analysis.
Preliminary irradiations for mechanisms and annealing
studies have been conducted and nondestructive
evaluations using the Barkhausen noise analysis and
hardness tests have been initiated. Further irradiation
for the evaluation of J-R curve characteristics of a weld
material will be started in the near future.
Long term thermal ageing studies have been continued.
Accelerated annealings at 450°C for one year do not
introduce any shift in the Charpy V transition
temperature of SA 533B base material and only a slight
increase was evident in the case of the corresponding
weld material.
In the area of environment sensitive cracking long term
stress corrosion cracking studies of different austenitic
stainless steels have been concluded and reported.
Comparable studies concerning the ferritic pressure
vessel and piping materials have been initiated. The
first corrosion fatigue tests in the recently
commissioned autoclave system have been completed
successfully.
Mechanistic studies of environment sensitive cracking in
pressure vessel steels have been continued and a
hydrogen-induced cracking model based on extensive
fractography has been outlined.
Corrosion studies have been concentrated on oxidation and
decontamination of austeniti; stainless steels in both
PWR and BWR conditions. In the area of low temperature
sensitisation studies long term annealings of different
stainless steel weld materials have been continued.
A sub-project has been initiated to generate basic
knowledge of the thermal fatigue behaviour of the
materials used in nuclear power planes. During this
reporting period a brief review of the problem areas has
been compiled.
In the area of repair welding the microstructural and
hardness studies revelled that the half bead repair
welding method man have some advantages compared try
normal manual arc welding. The differences are, however,
rather small and there exists a large scatter. The
microstructural studies of the HAZ reveal that a perfect
tempering effect is very difficult to obtain in halt bead
repair welding due to the wavelike shape of the fusion
line.
M3 - Report
SN - 951-38-1503-X
T3 - Valtion teknillinen tutkimuskeskus. Tutkimuksia - Research Reports
BT - Reliability of reactor materials program
PB - VTT Technical Research Centre of Finland
CY - Espoo
ER -