TY - JOUR
T1 - Effect of mechanical mismatch on fracture mechanical behavior of SA 508 - Alloy 52 narrow gap dissimilar metal weld
AU - Sarikka, Teemu
AU - Ahonen, Matias
AU - Mouginot, Roman
AU - Nevasmaa, Pekka
AU - Karjalainen-Roikonen, Päivi
AU - Ehrnstén, Ulla
AU - Hänninen, Hannu
N1 - Funding Information:
This study has been made in collaboration between Aalto University School of Engineering and VTT Technical Research Centre of Finland Ltd within the Structural integrity of Ni-base alloy welds (SINI)-research project funded by TEKES, Finnish (Teollisuuden Voima Oyj, Fortum Oyj and Fennovoima Oy) and Swedish (Vattenfall AB and OKG AB) energy producing industry . The authors wish to express their gratitude for the funding and participation of all the participants of the project.
Publisher Copyright:
© 2017 Elsevier Ltd
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2017/11/1
Y1 - 2017/11/1
N2 - In modern pressurized water reactor (PWR) designs,
dissimilar metal welds (DMW) between the reactor pressure
vessel (RPV) nozzles and safe-ends connected to the main
coolant pipes are manufactured using a narrow-gap welding
(NGW) technique. In addition to the new weld design, the
filler metals have been changed from conventional Alloys
82 and 182 to higher Cr containing Alloys 52 and 152 to
ensure the structural integrity of the welds during long
term operation. The changes in weld design and filler
metal have an effect on the mechanical mismatch state of
the DMW which has an effect on the fracture behavior of
the weld. For the experimental determination of the local
strength variations and the fracture mechanical behavior
of a modern NG-DMW, a weld mock-up consisting of SA 508
pressure vessel steel with AISI 309L/308L cladding, AISI
304 piping steel, and Alloy 52 weld metal was
manufactured. The NG-DMW was characterized in both
as-welded and post-weld heat treated (PWHT) conditions.
The results showed that the highest strength mismatch
existed between the carbon-depleted zone (CDZ) in the SA
508 heat-affected zone (HAZ) and the Alloy 52 weld metal.
High fracture toughness values were observed for the
different zones of the weld and the crack propagation
occurred towards the softer SA 508 HAZ CDZ.
AB - In modern pressurized water reactor (PWR) designs,
dissimilar metal welds (DMW) between the reactor pressure
vessel (RPV) nozzles and safe-ends connected to the main
coolant pipes are manufactured using a narrow-gap welding
(NGW) technique. In addition to the new weld design, the
filler metals have been changed from conventional Alloys
82 and 182 to higher Cr containing Alloys 52 and 152 to
ensure the structural integrity of the welds during long
term operation. The changes in weld design and filler
metal have an effect on the mechanical mismatch state of
the DMW which has an effect on the fracture behavior of
the weld. For the experimental determination of the local
strength variations and the fracture mechanical behavior
of a modern NG-DMW, a weld mock-up consisting of SA 508
pressure vessel steel with AISI 309L/308L cladding, AISI
304 piping steel, and Alloy 52 weld metal was
manufactured. The NG-DMW was characterized in both
as-welded and post-weld heat treated (PWHT) conditions.
The results showed that the highest strength mismatch
existed between the carbon-depleted zone (CDZ) in the SA
508 heat-affected zone (HAZ) and the Alloy 52 weld metal.
High fracture toughness values were observed for the
different zones of the weld and the crack propagation
occurred towards the softer SA 508 HAZ CDZ.
KW - alloy 52
KW - dissimilar metal weld
KW - fracture resistance
KW - low-alloy steel
KW - narrow-gap welding
KW - strength mismatch
UR - http://www.scopus.com/inward/record.url?scp=85029507571&partnerID=8YFLogxK
U2 - 10.1016/j.ijpvp.2017.08.003
DO - 10.1016/j.ijpvp.2017.08.003
M3 - Article
VL - 157
SP - 30
EP - 42
JO - International Journal of Pressure Vessels and Piping
JF - International Journal of Pressure Vessels and Piping
SN - 0308-0161
ER -