Evaluation of Welding Residual Stresses in Power Plant Facilities by Using a Newly Developed Indentation Technique

2002 ◽  
Author(s):  
Jae-il Jang ◽  
Dongil Son ◽  
Yeol Choi ◽  
Yun-Hee Lee ◽  
Won-Jae Ji ◽  
...  
Keyword(s):  
Residual Stress ◽  
Power Plant ◽  
Residual Stresses ◽  
Stress Measurement ◽  
Welding Residual Stress ◽  
Large Scatter ◽  
Indentation Technique ◽  
Cutting Test ◽  
Non Destructive ◽  
Non Destructive Techniques

It is well known that residual stress is one of the important problems in welding design/fabrications and sound maintenance of welded structures. Thus, the demand for quantitative evaluation of welding residual stress has been increased. However, conventional non-destructive techniques for welding residual stress measurement have many difficulties in in-field applications according to poor repeatability, large scatter of obtained data, complex procedures, inaccurate results, and etc. To overcome these difficulties, a newly developed indentation technique was proposed in this study, and applied to evaluate the welding residual stress in electric power plant facilities. By comparing with the stress values obtained from the destructive saw-cutting test, it could be concluded that the new indentation technique is very useful for quantitative/non-destructive evaluation of welding residual stresses in industrial fields such as power plant facilities.

Nondestructive Evaluation of Welding Residual Stress in Power Plant Facilities Using Instrumented Indentation Technique

2005 ◽  
Vol 297-300 ◽  
pp. 2122-2127 ◽  
Author(s):  
Yeol Choi ◽  
Yun Hee Lee ◽  
Jae Il Jang ◽  
Sang Ki Park ◽  
Kwang Ho Kim ◽  
...  
Keyword(s):  
Residual Stress ◽  
Power Plant ◽  
Welding Process ◽  
Indentation Load ◽  
Welding Residual Stress ◽  
Hole Drilling ◽  
Instrumented Indentation ◽  
Indentation Technique ◽  
Safety And Reliability ◽  
Depth Curve

The weld joints in power-plant pipelines have long been considered important sites for safety and reliability assessment. In particular, the residual stress in pipeline weldments induced by the welding process must be evaluated accurately before and during service. This study reports an indentation technique for evaluating welding residual stress nondestructively. Indentation load-depth curves were found to shift with the magnitude and direction of the residual stress. Nevertheless, contact depths in the stress-free and stressed states were constant at a specific indentation load. This means that residual stress induces additional load to keep contact depth constant at the same load. By taking these phenomena into account, welding residual stress was obtained directly from the indentation load-depth curve. In addition, the results were compared with values from the conventional hole-drilling and saw-cutting methods.

Residual Stress Management in Welding: Residual Stress Measurement and Improvement Treatments

2012 ◽  
Author(s):  
Jacob Kleiman ◽  
Yuri Kudryavtsev
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Residual Stresses ◽  
Stress Management ◽  
Stress Measurement ◽  
Industrial Applications ◽  
Welding Residual Stress ◽  
Residual Stress Measurement ◽  
Engineering Properties ◽  
Welded Structures

Residual stress (RS) can significantly affect engineering properties of materials and structural components, notably fatigue life, distortion, dimensional stability, corrosion resistance etc. Residual stresses play an exceptionally significant role in fatigue of welded elements. The influence of residual stresses on the multi-cycle fatigue life of butt and fillet welds can be compared with the effects of stress concentration. Even more significant are the effects of residual stresses on the fatigue life of welded elements in the case of relieving harmful tensile residual stresses and introducing beneficial compressive residual stresses in the weld toe zones. Residual stress management is a concept that addresses major aspects of residual stresses in welds and welded structures. According to the concept three major stages, i.e. RS determination, RS analysis and RS redistribution are considered and evaluated, either experimentally or theoretically to achieve the optimum performance of welded structures. All three stages as well as a number of new engineering tools such as ultrasonic computerized complex for residual stress measurement, UltraMARS, software for analysis of the effect of residual stresses on the fatigue life of welded elements and new technology and, based on it, compact system for beneficial redistribution of residual stresses by ultrasonic peening, UltraPeen will be discussed. Examples of industrial applications of the developed engineering tools for residual stress analysis and fatigue life improvement of welded elements and structures will be given.

scholarly journals A Review on Measurement Methods for Machining Induced Residual Stress

2019 ◽  
Vol 1 (2) ◽  
pp. 106 ◽  
Author(s):  
K. Saptaji ◽  
S. N. Afiqah ◽  
R. D. Ramdan
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Thermal Loading ◽  
Stress Measurement ◽  
Measurement Methods ◽  
Machining Process ◽  
Machining Parameters ◽  
Cutting Zone ◽  
Mechanical Machining ◽  
Non Destructive

The chip formation in mechanical machining / cutting process involves thermal loading and mechanical loading in the form of large plastic deformations, high strain, strain rates and high temperatures in the cutting zone. These loadings usually induce plastic deformation in the form of residual stresses in the surface and sub-surface of the machined workpiece. Residual stress issue is essential to be studied in order to control the quality and fatigue life of a component or part produced by machining process. Therefore, the magnitude and depth of the residual stresses into the workpiece sub-surface is important and necessary to be measured. The objective of this paper is to discuss various study on the effects of machining parameters on residual stress and residual stress measurement methods for machined workpiece namely non-destructive, semi-destructive and destructive methods. In addition, the effect of machining process into the metallurgical conditions of the workpiece in the form of microstructural changes is also discussed.

Measurement of Welding Residual Stress in Reactor Components

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].

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

2011 ◽  
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].

scholarly journals Residual stress management: Recent advances in engineering methods for non-destructive measurement and beneficial redistribution of residual stresses

2021 ◽  
Vol 66 (2) ◽  
pp. 83-95
Author(s):  
Jacob Kleiman
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Residual Stresses ◽  
Stress Management ◽  
Stress Measurement ◽  
Fatigue Behavior ◽  
Engineering Properties ◽  
Practical Engineering ◽  
Destructive Measurement ◽  
Non Destructive

Welding is used widely in the automotive industry for joining a variety of structural components and parts. Of paramount importance in these structures are their engineering properties, such as fatigue life, distortions, dimensional stability and corrosion resistance that can be affected considerably by the presence of residual stresses (RS). The knowledge of RS and the ability to control their distribution in welded structures is critical when evaluating their fatigue life and preventing catastrophic failures. An engineering concept of residual stress management (RSM) has been developed that addresses all aspects of residual stresses in structural elements. RSM includes three major stages in stress management, i.e. RS determination, RS analysis and RS redistribution. Using this approach, stresses in structures and materials can be evaluated in each specific case either theoretically or experimentally and the performance and fatigue behavior of such structures optimized. This paper is built as an overview of the RSM concept and its application in the fields of non-destructive measurement of residual and applied stresses and in treatment of structures with residual stresses to achieve better performance and longer fatigue life. All three stages of the RSM concept will be discussed and for each of the stages practical engineering approach examples will be given. An example of a project in which the residual stress distribution in a filet welded joint was measured, analyzed and changed by post-weld treatment will be presented to demonstrate the effectiveness of the RSM approach. The advancements in the modern tools used in this project for non-destructive measurement of residual stresses using an ultrasonic computerized complex for residual stress measurement and the ultrasonic peening for redistribution of the residual stresses that allowed improving the quality of the welds and increasing their fatigue life will also be presented.

Advanced Indentation Techniques: NDE for Flow Properties and Residual Stresses of Pipelines

2002 ◽  
Author(s):  
Yeol Choi ◽  
Dongil Son ◽  
Jae-Il Jang ◽  
Joon Park ◽  
Woo-Sik Kim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Residual Stresses ◽  
Structural Integrity ◽  
Potential Method ◽  
Indentation Load ◽  
Welding Residual Stress ◽  
Destructive Testing ◽  
Integrity Assessment ◽  
Indentation Technique

Structural integrity assessment is indispensable for preventing catastrophic failure of industrial structures/components/facilities that are faced with time-dependent and environmentally-accelerated degradation. This diagnosis of operating components should be done periodically for safe maintenance and economical repair. However, conventional standard methods for mechanical properties have the problems of bulky specimen, destructive and complex procedure of specimen sampling. So, an advanced indentation technique has been developed as a potential method for non-destructive testing of in-field structures. This technique measures indentation load-depth curve during indentation and analyzes the mechanical properties related to deformation such as yield strength, tensile strength and work-hardening index. Also the advanced indentation technique can evaluate residual stresses based on the concept that indentation load-depth curves were shifted with the direction and the magnitude of residual stress applied to materials. In this study, we characterized the tensile properties and welding residual stress of various Industrial pipeline steels through the new techniques, and the results are introduced and discussed.

scholarly journals Investigation of Clamping Effect on the Welding Residual Stress and Deformation of Monel Plates by Using the Ultrasonic Stress Measurement and Finite Element Method

2014 ◽  
Vol 137 (1) ◽  
Author(s):  
Yashar Javadi
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Acoustic Waves ◽  
Stress Measurement ◽  
Fe Analysis ◽  
Ultrasonic Waves ◽  
Welding Residual Stress ◽  
Longitudinal Residual Stress ◽  
Ultrasonic Stress Measurement

Welding of nickel-based alloys is increasingly used in the industry to manufacture many important components of the marine industries, chemical processing, etc. In this study, a 3D thermomechanical finite element (FE) analysis is employed to evaluate residual stresses and deformations caused by the tungsten inert gas (TIG) welding of Monel 400 (Nickel-Copper alloy) plates. The FE results related to the residual stresses and deformations have been verified by using the hole-drilling stress measurement and common dimensional measurement tools, respectively. Residual stresses analyzed by the FE simulation are then compared with those obtained from ultrasonic stress measurement. The ultrasonic stress measurement is based on acoustoelasticity law, which presents the relation between the acoustic waves and the stress of material. The ultrasonic stress measurement is carried out by using longitudinal critically refracted (LCR) waves which are longitudinal ultrasonic waves propagated parallel to the surface inside the tested material. Two welded plates are experimentally prepared (with and without using clamp) to investigate the clamping effect on the welding residual stress and deformations. By utilizing the FE analysis along with the LCR method, the distribution of longitudinal residual stress could be achieved. It has been concluded that the applied methodologies are enough accurate to distinguish the clamping effect on the welding residual stresses and deformations of Monel plates.

Finite Element Analyses of Residual Stresses in Typical Welded Joints Used in Nuclear Power Plants and Comparisons With Experiments

2010 ◽  
Author(s):  
Dean Deng ◽  
Kazuo Ogawa ◽  
Nobuyoshi Yanagida ◽  
Koichi Saito
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Residual Stresses ◽  
Welded Joints ◽  
Nuclear Power ◽  
Power Plants ◽  
Butt Joint ◽  
Welding Residual Stress ◽  
Dissimilar Metal ◽  
Water Reactors

Recent discoveries of stress corrosion cracking (SCC) at nickel-based metals in pressurized water reactors (PWRs) and boiling water reactors (BWRs) have raised concerns about safety and integrity of plant components. It has been recognized that welding residual stress is an important factor causing the issue of SCC in a weldment. In this study, both numerical simulation technology and experimental method were employed to investigate the characteristics of welding residual stress distribution in several typical welded joints, which are used in nuclear power plants. These joints include a thick plate butt-welded Alloy 600 joint, a dissimilar metal J-groove set-in joint and a dissimilar metal girth-butt joint. First of all, numerical simulation technology was used to predict welding residual stresses in these three joints, and the influence of heat source model on welding residual stress was examined. Meanwhile, the influence of other thermal processes such as cladding, buttering and heat treatment on the final residual stresses in the dissimilar metal girth-butt joint was also clarified. Secondly, we also measured the residual stresses in three corresponding mock-ups. Finally, the comparisons of the simulation results and the measured data have shed light on how to effectively simulate welding residual stress in these typical joints.

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