Two-Dimensional Residual Stress Mapping of Multilayer LTT Weld Joints Using the Contour Method

Abstract Background Prior work described an approach for mapping the two-dimensional spatial distribution of biaxial residual stress in plate-like samples, the approach combining multiple slitting measurements with elastic stress analysis. Objective This paper extends the prior work by applying a new variation of the slitting method that uses measurements of cut mouth opening displacement (CMOD) rather than back-face strain (BFS). Methods First, CMOD slitting is validated using an experiment where: BFS and CMOD are measured simultaneously on the same sample during incremental slitting; two residual stress profiles are computed, one from the BFS data and a second from the CMOD data; and the two residual stress profiles are compared. Following validation, multiple adjacent CMOD slitting measurements are used to construct two-dimensional maps of residual stress in plates cut from quenched aluminum. Results The two residual stress versus depth profiles, each computed separately from BFS or CMOD data, are in agreement, with compression near the plate boundaries (-150 MPa) and tension near the plate center (100 MPa); differences between the two stress profiles have a maximum of 25 MPa and a RMS of 7.2 MPa. Repeated biaxial residual stress mapping measurements show the CMOD technique is repeatable, and complementary contour method measurements show the mappings are valid. Aspects of CMOD and BFS deformations during slitting are also described and show they are generally complementary but that CMOD slitting is favorable in narrow samples.

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Measurement of Residual Stress in Reactor Nozzle Mock-Ups Containing Dissimilar Metal Welds

Volume 6B: Materials and Fabrication ◽

10.1115/pvp2014-28209 ◽

2014 ◽

Author(s):

Adrian T. DeWald ◽

Michael R. Hill ◽

Michael L. Benson ◽

David L. Rudland

Keyword(s):

Residual Stress ◽

Residual Stresses ◽

Stress Measurement ◽

Tensile Residual Stress ◽

Contour Method ◽

Two Dimensional ◽

Weld Residual Stress ◽

Accelerate Growth ◽

Primary Water ◽

Spatially Varying

Weld residual stresses can significantly impact the performance of structural components. Tensile residual stresses are of particular concern due to their ability to accelerate failure. For example, the presence of tensile residual stress can cause initiation and accelerate growth of primary water stress corrosion cracking (PWSCC). The contour method is a residual stress measurement technique capable of generating two dimensional maps of residual stress, which is particularly useful when applied to welds since they typically contain spatially varying residual stress distributions. The two-dimensional capability of the contour method enables detailed visualization of complex weld residual stress fields. This data can be used to identify locations and magnitude of tensile residual stress hot-spots. This paper provides a summary of the contour method and presents detailed results of contour method measurements made on a mock-up from the NRC/EPRI weld residual stress (WRS) program [1].

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Measurement of Welding Residual Stress in Reactor Components

ASME 2011 Small Modular Reactors Symposium ◽

10.1115/smr2011-6502 ◽

2011 ◽

Author(s):

Adrian T. DeWald ◽

Michael R. Hill

Keyword(s):

Residual Stress ◽

Residual Stresses ◽

Stress Measurement ◽

The United States ◽

Welding Residual Stress ◽

Contour Method ◽

Two Dimensional ◽

Stress Distributions ◽

Weld Residual Stress ◽

Metal Weld

Welding residual stresses can significantly impact the performance of structural components. Tensile residual stresses are of particular concern due to their ability to cause significant degradation to the PWSCC resistance of structural materials. The contour method is a residual stress measurement technique capable of generating two dimensional maps of residual stress, which is particularly useful when applied to welds due to the complex residual stress distributions that generally result. The two-dimensional capability of the contour method enables detailed visualization of complex weld residual stress fields. This data can be used to identify locations and magnitude of tensile residual stress hot-spots. This paper provides a summary of the contour method and presents detailed results of contour method measurements made on the dissimilar metal weld region of pressurizer relief nozzles removed from the cancelled WNP-3 plant in the United States as part of the NRC/EPRI weld residual stress (WRS) program [1].

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Measurement of Welding Residual Stress in Dissimilar Metal Welds Using the Contour Method

ASME 2011 Pressure Vessels and Piping Conference: Volume 6, Parts A and B ◽

10.1115/pvp2011-57720 ◽

2011 ◽

Cited By ~ 2

Author(s):

Adrian T. DeWald ◽

Michael R. Hill ◽

Eric Willis

Keyword(s):

Residual Stress ◽

Residual Stresses ◽

Stress Measurement ◽

The United States ◽

Welding Residual Stress ◽

Contour Method ◽

Two Dimensional ◽

Stress Distributions ◽

Dissimilar Metal ◽

Weld Residual Stress

Welding residual stresses can significantly impact the performance of structural components. Tensile residual stresses are of particular concern due to their ability to cause significant degradation to the PWSCC resistance of structural materials. The contour method is a residual stress measurement technique capable of generating two dimensional maps of residual stress, which is particularly useful when applied to welds due to the complex residual stress distributions that generally result. The two-dimensional capability of the contour method enables detailed visualization of complex weld residual stress fields. This data can be used to identify locations and magnitude of tensile residual stress hot-spots. This paper provides a summary of the contour method and presents detailed results of contour method measurements made on the dissimilar metal weld region of pressurizer relief nozzles removed from the cancelled WNP-3 plant in the United States as part of the NRC/EPRI weld residual stress (WRS) program [1].

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Residual Stress Mapping in Welds Using the Contour Method

Materials Science Forum ◽

10.4028/www.scientific.net/msf.490-491.294 ◽

2005 ◽

Vol 490-491 ◽

pp. 294-299 ◽

Cited By ~ 10

Author(s):

Ying Zhang ◽

S. Pratihar ◽

Michael E. Fitzpatrick ◽

Lyndon Edwards

Keyword(s):

Residual Stress ◽

Stress Measurement ◽

Contour Method ◽

Welding Parameters ◽

Stress Profile ◽

Efficient Manner ◽

Cross Sectional ◽

Stress Evaluation ◽

Residual Stress Profile ◽

Stress Mapping

The contour method, a newly-invented sectioning technique for residual stress measurement, has the potential to measure the cross-sectional residual stress profile of a weld in a simple and time-efficient manner. In this paper we demonstrate the capability of the contour method to measure cross-sectional residual stress profiles, which are compared with neutron diffraction measurements and show excellent agreement. The results provide useful information for safetycritical design of welded components and optimization of welding parameters, and also illustrate the potential of the contour technique as a powerful tool for residual stress evaluation.

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Residual Stress Mapping for an Excavate and Weld Repair Mockup

Volume 6B: Materials and Fabrication ◽

10.1115/pvp2016-63197 ◽

2016 ◽

Author(s):

Mitchell D. Olson ◽

Adrian T. DeWald ◽

Michael R. Hill ◽

Steven L. McCracken

Keyword(s):

Residual Stress ◽

Weld Metal ◽

Biaxial Stress ◽

Contour Method ◽

Weld Repair ◽

Weld Residual Stress ◽

Metal Plates ◽

Asme Code ◽

Stress Mapping ◽

Residual Stress Modeling

This paper describes a sequence of residual stress measurements made to determine a two-dimensional map of biaxial residual stress (weld direction and transverse to the weld direction) in a mockup with a partial arc excavation and weld repair (EWR), as well as three additional maps of one component of residual stress. The mockup joins two dissimilar metal plates (SA-508 low alloy steel and Type 316L stainless steel) with a nickel alloy weld metal (Alloy 82/182). A partial groove is then excavated and filled in with SCC resistant Alloy 52M weld metal. The mockup was fabricated to investigate the effectiveness of the EWR mitigation methodology being investigated through the development of ASME Code Case N-847 to address stress corrosion cracking problems in reactor coolant system butt welds. The biaxial stress map is determined using a newly developed technique called primary slice removal (PSR) mapping, which uses both contour method and slitting measurements. In this case, the technique requires measuring the longitudinal stress along a plane and the long transverse stress remaining in a slice removed adjacent to that plane. This paper includes descriptions of the experiments and data analysis. The measured residual stresses follow expected trends and compare favorably to the results of computational weld residual stress modeling.

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Residual Stress Mapping in Welds Using the Contour Method

Materials Science Forum - Residual Stresses VII, ICRS7 ◽

10.4028/0-87849-969-5.294 ◽

2005 ◽

pp. 294-299 ◽

Cited By ~ 2

Author(s):

Ying Zhang ◽

S. Pratihar ◽

Michael E. Fitzpatrick ◽

Lyndon Edwards

Keyword(s):

Residual Stress ◽

Contour Method ◽

Stress Mapping

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Biaxial Residual Stress Mapping in a PWR Dissimilar Metal Weld

Volume 6B: Materials and Fabrication ◽

10.1115/pvp2013-97246 ◽

2013 ◽

Cited By ~ 5

Author(s):

Michael R. Hill ◽

Mitchell D. Olson

Keyword(s):

Residual Stress ◽

Axial Stress ◽

Image Correlation ◽

Contour Method ◽

Pressurized Water Reactor ◽

Pressurized Water ◽

Dissimilar Metal ◽

Stress Mapping ◽

Metal Weld ◽

Alloy Weld

This paper describes a sequence of residual stress measurements made to determine a two-dimensional map of biaxial residual stress in a dissimilar metal welded nozzle typical of a nuclear pressurized water reactor (PWR). The present experimental work follows on the numerical analysis reported earlier, in PVP2012-78885. The measurement subject is a cylindrical nozzle, removed from a PWR pressure vessel, having a nickel alloy weld joining a stainless steel safe end to a low-alloy steel vessel. Biaxial residual stress was determined in a series of experimental steps using strain gage measurements, the contour method, and slitting. Confirmatory measurements were also performed (including digital image correlation and neutron diffraction). The paper includes descriptions of the experimental steps, data reduction, and residual stress results, along with a comparison between measurements and output from a weld simulation. The measured hoop stress in the weld region is tensile near the OD (300 MPa) and compressive near the ID (−400 MPa); the measured axial stress is tensile near the OD (150 MPa) and compressive near the ID (−150 MPa).

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Plasticity in the Contour Method of Residual Stress Measurement

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.996.337 ◽

2014 ◽

Vol 996 ◽

pp. 337-342 ◽

Cited By ~ 13

Author(s):

Yéli Traoré ◽

Foroogh Hosseinzadeh ◽

Peter John Bouchard

Keyword(s):

Residual Stress ◽

Finite Element Analysis ◽

Material Removal ◽

Stress Measurement ◽

Contour Method ◽

Experimental Measurements ◽

Two Dimensional ◽

Element Analysis ◽

High Magnitude ◽

Insight Into

The contour method is a powerful measurement technique that can provide two-dimensional maps of residual stress in engineering components. However, like most strain relief techniques, it can lose accuracy owing to plasticity when residual stresses have high magnitude relative to the yield strength of the material being measured. Finite element analysis is utilised to provide an insight into how plasticity introduced by material removal can influence the accuracy of the contour method. In addition the effect of component restraint during the cut is investigated and the results discussed with respect to published experimental measurements.

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