Effect of mechanical mismatch on fracture mechanical behavior of SA 508 - Alloy 52 narrow gap dissimilar metal weld

Teemu Sarikka, Matias Ahonen, Roman Mouginot, Pekka Nevasmaa, Päivi Karjalainen-Roikonen, Ulla Ehrnstén, Hannu Hänninen

Research output: Contribution to journalArticleScientificpeer-review

6 Citations (Scopus)

Abstract

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.
Original languageEnglish
Pages (from-to)30-42
Number of pages13
JournalInternational Journal of Pressure Vessels and Piping
Volume157
DOIs
Publication statusPublished - 1 Nov 2017
MoE publication typeA1 Journal article-refereed

Fingerprint

Dissimilar metals
Welds
Filler metals
Heat affected zone
Carbon
Metals
Steel
Pressurized water reactors
Structural integrity
Steel structures
Pressure vessels
Coolants
Fracture toughness

Keywords

  • alloy 52
  • dissimilar metal weld
  • fracture resistance
  • low-alloy steel
  • narrow-gap welding
  • strength mismatch

Cite this

Sarikka, Teemu ; Ahonen, Matias ; Mouginot, Roman ; Nevasmaa, Pekka ; Karjalainen-Roikonen, Päivi ; Ehrnstén, Ulla ; Hänninen, Hannu. / Effect of mechanical mismatch on fracture mechanical behavior of SA 508 - Alloy 52 narrow gap dissimilar metal weld. In: International Journal of Pressure Vessels and Piping. 2017 ; Vol. 157. pp. 30-42.
@article{a08af34a31154c9f8b3c74db54dc95de,
title = "Effect of mechanical mismatch on fracture mechanical behavior of SA 508 - Alloy 52 narrow gap dissimilar metal weld",
abstract = "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.",
keywords = "alloy 52, dissimilar metal weld, fracture resistance, low-alloy steel, narrow-gap welding, strength mismatch",
author = "Teemu Sarikka and Matias Ahonen and Roman Mouginot and Pekka Nevasmaa and P{\"a}ivi Karjalainen-Roikonen and Ulla Ehrnst{\'e}n and Hannu H{\"a}nninen",
note = "CA2: BA2506 CA2: BA2405 CA2: BA2505 CA2: BA2506 AU2: Ahonen, Matias AU2: Nevasmaa, Pekka AU2: Karjalainen-Roikonen, P{\"a}ivi AU2: Ehrnst{\'e}n, Ulla",
year = "2017",
month = "11",
day = "1",
doi = "10.1016/j.ijpvp.2017.08.003",
language = "English",
volume = "157",
pages = "30--42",
journal = "International Journal of Pressure Vessels and Piping",
issn = "0308-0161",
publisher = "Elsevier",

}

Effect of mechanical mismatch on fracture mechanical behavior of SA 508 - Alloy 52 narrow gap dissimilar metal weld. / Sarikka, Teemu; Ahonen, Matias; Mouginot, Roman; Nevasmaa, Pekka; Karjalainen-Roikonen, Päivi; Ehrnstén, Ulla; Hänninen, Hannu.

In: International Journal of Pressure Vessels and Piping, Vol. 157, 01.11.2017, p. 30-42.

Research output: Contribution to journalArticleScientificpeer-review

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 - CA2: BA2506 CA2: BA2405 CA2: BA2505 CA2: BA2506 AU2: Ahonen, Matias AU2: Nevasmaa, Pekka AU2: Karjalainen-Roikonen, Päivi AU2: Ehrnstén, Ulla

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 -