Weldability Evaluation of P87 and 230W Filler Metals in Alloy 230 to Grade P91 Steel Dissimilar Metal Weld

2017 ◽  
Author(s):  
Conner Sarich ◽  
Boian Alexandrov ◽  
Avraham Benatar ◽  
Jorge Penso ◽  
Jerry Kovacich
Keyword(s):  
Stress Relaxation ◽  
Filler Metal ◽  
Tensile Load ◽  
Solidification Cracking ◽  
P91 Steel ◽  
Dissimilar Metal ◽  
Dissimilar Metal Weld ◽  
Cracking Mode ◽  
Filler Metals ◽  
Metal Weld

The objective of this study was to perform comparative weldability evaluation of weld filler metals for an Alloy 230 / P91 steel dissimilar metal weld (DMW) that will be used in once through steam generator (OTSG) on an offshore oil platform. The weldability characteristics of filler metals EPRI P87 and Haynes 230W were evaluated using the cast pin tear test (CPTT) and a stress relaxation cracking (SRC) test in combination with metallurgical characterization using light optical and scanning electron microscopy. Solidification cracking susceptibility rankings generated with the CPTT showed that undiluted P87 filler metal had better resistance to solidification cracking than undiluted Alloy 230W. The SRC testing preformed in the Gleeble 3800™ thermo-mechanical simulator showed that none of the tested welds failed in stress relaxation cracking mode during simulated service at 600°C under constant displacement and tensile load at 90% of the high temperature yield strength. During the SRC testing, filler metal 230W exhibited some level of stress relaxation, while no evidence of stress relaxation was found in filler metal P87.

scholarly journals Examining Stress Relaxation in a Dissimilar Metal Weld Subjected to Postweld Heat Treatment

2018 ◽  
Vol 7 (4) ◽  
pp. 20180018
Author(s):  
K. Abburi Venkata ◽  
S. Khayatzadeh ◽  
A. Achouri ◽  
J. Araujo de Oliveira ◽  
A. N. Forsey ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Stress Relaxation ◽  
Postweld Heat Treatment ◽  
Dissimilar Metal ◽  
Dissimilar Metal Weld ◽  
Postweld Heat ◽  
Metal Weld

Investigation of Dissimilar Metal Weld Behavior

2014 ◽  
Vol 782 ◽  
pp. 149-154 ◽  
Author(s):  
Zuzana Skoumalová ◽  
Eliška Keilová
Keyword(s):  
Filler Metal ◽  
Optical Microscope ◽  
Accelerated Ageing ◽  
Term Operation ◽  
Dissimilar Metal ◽  
Light Optical Microscope ◽  
Dissimilar Metal Weld ◽  
Metal Weld ◽  
Microhardness Tester

This paper is focused on the research of a dissimilar metal weld (DMW) behavior during long-term NPP (VVER) operation. Investigated material comes from decommissioned non-operated VVER 440 reactor (NPP Nord, Greifswald) in Germany. The weld joining of ferritic 22K and austenitic 08Ch18N10T steels was performed in VÍTKOVICE a. s. The buttering first and second DMW layers are made from Sv-10CH16N25AM6 and Sv-04CH19N11M3 materials, respectively; the filler metal is EA-400/10T. The DMW microstructure and microhardness were evaluated in original state and after simulation of 30, 40 and 60 years of operation. Accelerated ageing at 450°C was designed to simulate long-term operation of the material. The aim of the research was to compare the original DMW with the aged ones and to determine the possible long-term operation effect on their microstructure and microhardness. Light optical microscope Nikon EPIPHOT 300 equipped with analyzer NIS Elements 3.0 and microhardness tester MHT Anton Paar 4 were used for the evaluation. The research program funded by ČEZ Company was ordered by ÚAM Brno in ÚJV Řež, a. s.

A crack-location correction for T0 analysis of an alloy 52 dissimilar metal weld

2019 ◽  
Vol 214 ◽  
pp. 320-334 ◽  
Author(s):  
Sebastian Lindqvist ◽  
Matias Ahonen ◽  
Jari Lydman ◽  
Pentti Arffman ◽  
Hannu Hänninen
Keyword(s):  
Crack Location ◽  
Dissimilar Metal ◽  
Dissimilar Metal Weld ◽  
Metal Weld

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.

scholarly journals Experimental Characterisation and Numerical Modelling of Residual Stresses in a Nuclear Safe-End Dissimilar Metal Weld Joint

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1298
Author(s):  
Shuyan Zhang ◽  
Zhuozhi Fan ◽  
Jun Li ◽  
Shuwen Wen ◽  
Sanjooram Paddea ◽  
...  
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Residual Stresses ◽  
Weld Joint ◽  
Steel Tube ◽  
Contour Method ◽  
Fe Modelling ◽  
Dissimilar Metal ◽  
Dissimilar Metal Weld ◽  
Metal Weld

In this study, a mock-up of a nuclear safe-end dissimilar metal weld (DMW) joint (SA508-3/316L) was manufactured. The manufacturing process involved cladding and buttering of the ferritic steel tube (SA508-3). It was then subjected to a stress relief heat treatment before being girth welded together with the stainless steel tube (316L). The finished mock-up was subsequently machined to its final dimension. The weld residual stresses were thoroughly characterised using neutron diffraction and the contour method. A detailed finite element (FE) modelling exercise was also carried out for the prediction of the weld residual stresses resulting from the manufacturing processes of the DMW joint. Both the experimental and numerical results showed high levels of tensile residual stresses predominantly in the hoop direction of the weld joint in its final machined condition, tending towards the OD surface. The maximum hoop residual stress determined by the contour method was 500 MPa, which compared very well with the FE prediction of 467.7 Mpa. Along the neutron scan line at the OD subsurface across the weld joint, both the contour method and the FE modelling gave maximum hoop residual stress near the weld fusion line on the 316L side at 388.2 and 453.2 Mpa respectively, whereas the neutron diffraction measured a similar value of 480.6 Mpa in the buttering zone near the SA508-3 side. The results of this research thus demonstrated the reasonable consistency of the three techniques employed in revealing the level and distribution of the residual stresses in the DMW joint for nuclear applications.

Welding overlay analysis of dissimilar metal weld cracking of feedwater nozzle

2010 ◽  
Vol 87 (1) ◽  
pp. 26-32 ◽  
Author(s):  
Y.L. Tsai ◽  
Li. H. Wang ◽  
T.W. Fan ◽  
Sam Ranganath ◽  
C.K. Wang ◽  
...  
Keyword(s):  
Overlay Analysis ◽  
Dissimilar Metal ◽  
Dissimilar Metal Weld ◽  
Metal Weld

Study of the Stress State of a Dissimilar Metal Weld Due to Manufacturing and Operational Conditions

2022 ◽  
Author(s):  
Bernadett Spisák ◽  
Zoltán Bézi ◽  
Szabolcs Szávai
Keyword(s):  
Residual Stresses ◽  
Load Capacity ◽  
Maximum Load ◽  
Operational Conditions ◽  
Manufacturing Method ◽  
Dissimilar Metal ◽  
Welding Defects ◽  
Complex Procedure ◽  
Dissimilar Metal Weld ◽  
Metal Weld

Welding is accompanied by the presence of weld residual stresses, which in case of dissimilar metal welds even with post weld heat treatment cannot be removed completely therefore they should be considered when assessing possible welding defects. The measurement of residual stress in metal weld is a very complex procedure and also in the investigated case could not be carried out as it is the part of a working plant. However, by modelling these processes, the residual stresses and deformation of the components caused by this manufacturing method can be determined. It is important to calculate these values as accurately as possible to determine the maximum load capacity of the structure. The structure under examination was the dissimilar metal weld of a VVER-440 steam generator. 2D simulations were performed, where temperature and phase-dependent material properties were implemented. Different loading scenarios were considered in the numerical analysis. The results can be useful to determine the real loading conditions of a given component and can be used to predict stress corrosion crack initiation locations, as well as to evaluate the lifetime and failure mode prediction of welded joints.

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