In-situ investigation of thermal aging effect on oxide formation in Ni-base alloy/low alloy steel dissimilar metal weld interfaces

2014 ◽  
Vol 86 ◽  
pp. 295-303 ◽  
Author(s):  
Jongjin Kim ◽  
Seung Hyun Kim ◽  
Kyung Joon Choi ◽  
Chi Bum Bahn ◽  
Il Soon Hwang ◽  
...  
Keyword(s):  
Thermal Aging ◽  
Base Alloy ◽  
Aging Effect ◽  
Low Alloy Steel ◽  
Oxide Formation ◽  
Dissimilar Metal ◽  
In Situ Investigation ◽  
Dissimilar Metal Weld ◽  
Metal Weld

Effects of thermal aging on microstructures of low alloy steel–Ni base alloy dissimilar metal weld interfaces

2013 ◽  
Vol 441 (1-3) ◽  
pp. 493-502 ◽  
Author(s):  
Kyoung Joon Choi ◽  
Jong Jin Kim ◽  
Bong Ho Lee ◽  
Chi Bum Bahn ◽  
Ji Hyun Kim
Keyword(s):  
Alloy Steel ◽  
Thermal Aging ◽  
Base Alloy ◽  
Low Alloy Steel ◽  
Dissimilar Metal ◽  
Dissimilar Metal Weld ◽  
Metal Weld

Fracture assessment for a dissimilar metal weld of low alloy steel and Ni-base alloy

2012 ◽  
Vol 90-91 ◽  
pp. 61-68 ◽  
Author(s):  
Takuya Ogawa ◽  
Masao Itatani ◽  
Toshiyuki Saito ◽  
Takahiro Hayashi ◽  
Chihiro Narazaki ◽  
...  
Keyword(s):  
Alloy Steel ◽  
Base Alloy ◽  
Low Alloy Steel ◽  
Dissimilar Metal ◽  
Fracture Assessment ◽  
Dissimilar Metal Weld ◽  
Metal Weld

scholarly journals NANO-STRUCTURAL AND NANO-CHEMICAL ANALYSIS OF NI-BASE ALLOY/LOW ALLOY STEEL DISSIMILAR METAL WELD INTERFACES

2012 ◽  
Vol 44 (5) ◽  
pp. 491-500 ◽  
Author(s):  
Kyoung-Joon Choi ◽  
Sang-Hun Shin ◽  
Jong-Jin Kim ◽  
Ju-Ang Jung ◽  
Ji-Hyun Kim
Keyword(s):  
Chemical Analysis ◽  
Alloy Steel ◽  
Base Alloy ◽  
Low Alloy Steel ◽  
Dissimilar Metal ◽  
Dissimilar Metal Weld ◽  
Metal Weld

scholarly journals THREE DIMENSIONAL ATOM PROBE STUDY OF NI-BASE ALLOY/LOW ALLOY STEEL DISSIMILAR METAL WELD INTERFACES

2012 ◽  
Vol 44 (6) ◽  
pp. 673-682 ◽  
Author(s):  
Kyoung-Joon Choi ◽  
Sang-Hun Shin ◽  
Jong-Jin Kim ◽  
Ju-Ang Jung ◽  
Ji-Hyun Kim
Keyword(s):  
Alloy Steel ◽  
Base Alloy ◽  
Three Dimensional ◽  
Atom Probe ◽  
Low Alloy Steel ◽  
Dissimilar Metal ◽  
Dissimilar Metal Weld ◽  
Metal Weld

scholarly journals Evolution of a low-alloy steel/nickel superalloy dissimilar metal weld during post-weld heat treatment

2021 ◽  
Author(s):  
C.V. da Silva Lima ◽  
M. Verdier ◽  
F. Robaut ◽  
J. Ghanbaja ◽  
G. Badinier ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Alloy Steel ◽  
Nickel Superalloy ◽  
Post Weld Heat Treatment ◽  
Low Alloy Steel ◽  
Dissimilar Metal ◽  
Dissimilar Metal Weld ◽  
Metal Weld ◽  
Weld Heat

Brittle Fracture Analysis of a Dissimilar Metal Weld

2013 ◽  
Author(s):  
A. Blouin ◽  
S. Chapuliot ◽  
S. Marie ◽  
J. M. Bergheau ◽  
C. Niclaeys
Keyword(s):  
Brittle Fracture ◽  
Weld Joint ◽  
Threshold Stress ◽  
Base Alloy ◽  
Welding Process ◽  
Loading Conditions ◽  
Brittle To Ductile Transition ◽  
Dissimilar Metal ◽  
Dissimilar Metal Weld ◽  
Metal Weld

One important part of the integrity demonstration of large ferritic components is based on the demonstration that they could never undergo brittle fracture. Connections between a ferritic component and an austenitic piping (Dissimilar Metal Weld — DMW) have to respect these rules, in particular the Heat Affected Zone (HAZ) created by the welding process and which encounters a brittle-to-ductile transition. Within that frame, the case considered in this article is a Ni base alloy narrow gap weld joint between a ferritic pipe (A533 steel) and an austenitic pipe (316L stainless steel). The aim of the present study is to show that in the same loading conditions, the weld joint is less sensitive to the brittle fracture than the surrounding ferritic part of the component. That is to say that the demonstration should be focused on the ferritic base metal which is the weakest material. The bases of this study rely on a stress-based criterion developed by Chapuliot et al., using a threshold stress (σth) below which the cleavage cannot occur. This threshold stress can be used to define the brittle crack occurrence probability, which means it is possible to determine the highest loading conditions without any brittle fracture risk.

Thermal Aging Assessment and Microstructural Investigations of Alloy 52 Dissimilar Metal Welds for Nuclear Components

2019 ◽  
Author(s):  
Miguel Yescas ◽  
Pierre Joly ◽  
François Roch
Keyword(s):  
Fracture Toughness ◽  
Alloy Steel ◽  
Thermal Aging ◽  
Base Alloy ◽  
Narrow Gap ◽  
Low Alloy Steel ◽  
Nickel Base Alloy ◽  
Pressurized Water ◽  
Dissimilar Metal ◽  
Nickel Base

Abstract Dissimilar Metal Welds (DMW) are commonly found between the ferritic low alloy steel heavy section components and the austenitic stainless steel piping sections in nuclear power plants. In the EPR™ design which is the latest FRAMATOME Pressurized water reactor (PWR) these DMW involve a narrow gap technology with no buttering, and only one bead per layer of a nickel base alloy weld filler metal (Alloy 52). In order to assess the thermal aging performance of this relatively new narrow gap DMW design, a significant internal R&D program was launched some years ago. Several representative mock-ups were thoroughly characterized in the initial condition as well as in the thermal aged condition, up to 50,000 hours aging at 350°C. The characterisations were focused on the fusion line between the ferritic low alloy steel (LAS) and the nickel base alloy since a particular microstructure is present in this area, especially in the carbon depleted area of the Heat Affected Zone (HAZ) which is often regarded as the weak zone of the weld joint. Metallography, hardness, nanohardness, chemical analyses, and Atom Probe Tomography, as well as fracture toughness tests were carried out on different specimens in different thermal aging conditions. The results show that the fracture toughness behaviour in the ductile-brittle domain of the low alloy steel carbon depleted HAZ at the interface with the alloy 52 weld metal of the DMWs is excellent, even for a thermal ageing equivalent to 60 years at service temperature. This was found in spite of the carbon depleted zone of the HAZ, the variations of hardness, chemical composition, particularly the carbon gradients, and the thermal aging effect induced by phosphorous segregation at grain boundaries.

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