Determining Residual Stresses in Weld Joints of DN 850 Pipes by Spot Drilling Combined with Electronic Speckle Pattern Interferometry

2021 ◽  
Vol 410 ◽  
pp. 366-371
Author(s):  
Igor N. Odintsev ◽  
Taras P. Plugatar ◽  
Andrey A. Apalkov
Keyword(s):  
Residual Stresses ◽  
Weld Joint ◽  
Speckle Pattern ◽  
Joint Implementation ◽  
Field Conditions ◽  
Electronic Speckle Pattern Interferometry ◽  
Weld Joints ◽  
Study Results ◽  
Drilling Technique ◽  
And Performance

Residual welding stresses affect significantly the strength, durability, and performance of structures. Therefore, there is an urgent need for developing and implementing techniques and equipment that allow reliably estimating stresses in experiments. This paper considers some aspects of the joint implementation of electronic speckle pattern interferometry and the spot drilling technique to determine these characteristics under the field conditions. The results of determining the distribution of residual stresses in the weld joint areas of DN 850 pipes are given for various welding modes. The study results are of independent significance and herewith, demonstrate the efficiency of the equipment developed to solve similar problems.

Development of Residual Stress Improvement for Nuclear Pressure Vessel Instrumentation Nozzle Weld Joint (P-43+P-8) by Means of Induction Heating

2006 ◽  
Author(s):  
Takuro Terajima ◽  
Takashi Hirano
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Residual Stresses ◽  
Induction Heating ◽  
Weld Joint ◽  
Thermal Stresses ◽  
Pressure Vessels ◽  
Weld Joints

As a counter measurement of intergranular stress corrosion cracking (IGSCC) in boiling water reactors, the induction heating stress improvement (IHSI) has been developed as a method to improve the stress factor, especially residual stresses in affected areas of pipe joint welds. In this method, a pipe is heated from the outside by an induction coil and cooled from the inside with water simultaneously. By thermal stresses to produce a temperature differential between the inner and outer pipe surfaces, the residual stress inside the pipe is improved compression. IHSI had been applied to weld joints of austenitic stainless steel pipes (P-8+P-8). However IHSI had not been applied to weld joints of nickel-chromium-iron alloy (P-43) and austenitic stainless steel (P-8). This weld joint (P-43+P-8) is used for instrumentation nozzles in nuclear power plants’ reactor pressure vessels. Therefore for the purpose of applying IHSI to this one, we studied the following. i) Investigation of IHSI conditions (Essential Variables); ii) Residual stresses after IHSI; iii) Mechanical properties after IHSI. This paper explains that IHSI is sufficiently effective in improvement of the residual stresses for this weld joint (P-43+P-8), and that IHSI does not cause negative effects by results of mechanical properties, and IHSI is verified concerning applying it to this kind of weld joint.

Modeling and Measurement of Residual Stresses along the Process Chain of Autofrettaged Components by Using FEA and Hole-Drilling Method with ESPI

2013 ◽  
Vol 768-769 ◽  
pp. 79-86 ◽  
Author(s):  
Horst Brünnet ◽  
Dirk Bähre ◽  
Theo J. Rickert ◽  
Dominik Dapprich
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Residual Stresses ◽  
Speckle Pattern ◽  
Residual Stress Distribution ◽  
Electronic Speckle Pattern Interferometry ◽  
Hole Drilling ◽  
Element Analysis ◽  
Hole Drilling Method ◽  
Drilling Method

The incremental hole-drilling method is a well-known mechanical measurement procedure for the analysis of residual stresses. The newly developed PRISM® technology by Stresstech Group measures stress relaxation optically using electronic speckle pattern interferometry (ESPI). In case of autofrettaged components, the large amount of compressive residual stresses and the radius of the pressurized bores can be challenging for the measurement system. This research discusses the applicability of the measurement principle for autofrettaged cylinders made of steel AISI 4140. The residual stresses are measured after AF and after subsequent boring and reaming. The experimental residual stress depth profiles are compared to numerically acquired results from a finite element analysis (FEA) with the software code ABAQUS. Sample preparation will be considered as the parts have to be sectioned in half in order to access the measurement position. Following this, the influence of the boring and reaming operation on the final residual stress distribution as well as the accuracy of the presented measurement setup will be discussed. Finally, the usability of the FEA method in early design stages is discussed in order to predict the final residual stress distribution after AF and a following post-machining operation.

scholarly journals Assessing Shot-Peening Residual Stresses by Using the Incremental Hole-Drilling Technique and Laser Interferometry (DSPI)

2014 ◽  
Vol 996 ◽  
pp. 269-276
Author(s):  
João P. Nobre ◽  
Miguel Oliveira ◽  
Armando Albertazzi ◽  
Matias Viotti ◽  
António Castanhola Batista ◽  
...  
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Shot Peening ◽  
Speckle Pattern ◽  
Strain Relaxation ◽  
Laser Interferometry ◽  
Hole Drilling ◽  
X Ray Diffraction ◽  
Incremental Hole Drilling ◽  
Drilling Technique

The incremental hole-drilling technique was applied to determine residual stress profiles in shot-peened steel layers. The accuracy of using an enhanced Digital Speckle Pattern Interferometry technique for measuring the strain relaxation arising around the drilled holes and, consequently, the in-depth residual stress distribution induced by shot-peening, was evaluated. The experimental results were systematically compared with those determined using standard electric strain-gauges. The X-ray diffraction technique was chosen as reference due to its high accuracy to determine shot-peening residual stresses.

Study of inhomogeneous fields of residual stresses using step-by-step enlarged crack method in combination with electronic speckle pattern interferometry (ESPI)

2021 ◽  
Vol 87 (9) ◽  
pp. 50-58
Author(s):  
S. M. Usov ◽  
I. A. Razumovsky ◽  
I. A. Odintsev
Keyword(s):  
Residual Stresses ◽  
Crack Length ◽  
Speckle Pattern ◽  
Structural Heterogeneity ◽  
Initial Position ◽  
Electronic Speckle Pattern Interferometry ◽  
Displacement Fields ◽  
Deformation Response ◽  
Gradient Fields ◽  
High Level

This article covers the development of methodological issues, software, experimental equipment, and practical application of the method of sequentially increasing cracks for studying inhomogeneous high-gradient fields of residual stresses (RS) that occur in areas of structural heterogeneity in flat construction parts (e.g., welded joints). Method of electronic speckle pattern interferometry (ESPI) is used to detect the deformation response in the form of the fields of displacement of the surface of the object under study arising from formation of successively increasing crack. ESPI provide contactless registration of movements directly in a digital form with high accuracy. The scheme of a specialized interferometer is described along with the features of the procedure for registering the displacement fields arising from a stepwise increase of the crack length. A return device provided removing of the object under study out of the optical zone and then return it to the initial position after performing the necessary mechanical operations. The accuracy of the procedure for calculating RS is estimated on the basis of mathematical processing of the experimentally obtained dependences of SIF on the crack length. An example of using the developed methods, equipment and programs for studying the RS distribution in stir welding joint of the sheets of aircraft alloy 1163T with a high level of crack resistance is given.

Computation of residual stresses, distortion, and thermogravimetric analysis of Inconel 625 weld joints

2020 ◽  
pp. 095440622097405
Author(s):  
J Sivakumar ◽  
Nanda Naik Korra ◽  
P Vasantharaja
Keyword(s):  
Thermogravimetric Analysis ◽  
Residual Stresses ◽  
Weld Joint ◽  
Vertical Displacement ◽  
Inert Gas ◽  
Angular Distortion ◽  
Inconel 625 ◽  
Weld Joints ◽  
Before And After ◽  
Height Gauge

In the current investigation, Inconel 625 weld joints were fabricated by Activated tungsten inert gas (A-TIG) and Tungsten inert gas (TIG) welding techniques. The joint configurations employed square butt and V groove edge preparations. Residual stresses measurement was carried out by X-ray diffraction using the Proto iXRD measurement system. Distortion in weld joints was estimated by measuring the vertical displacement on the grids marked on the weld joints before and after welding by using an electronic height gauge. Weldment revealed distinctive microstructure, peak tensile residual stress, and angular distortion. A-TIG weld joint exhibited lower residual stresses and distortion compared to the TIG weld joint. Thermogravimetric analysis (TGA) has inferred that the fusion zone of A-TIG and TIG weldments revealed better hot corrosion resistance at high temperatures.

A Study on Measurement of Welding Residual Stress Using ESPI System

2006 ◽  
Vol 324-325 ◽  
pp. 859-862 ◽  
Author(s):  
Kyung Su Kim ◽  
Seung Bok Choi ◽  
Jang Hyun Lee ◽  
Seong Mo Park ◽  
Beom Il Kim ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Speckle Pattern ◽  
Three Dimensional ◽  
Welding Residual Stress ◽  
Electronic Speckle Pattern Interferometry ◽  
Fe Model ◽  
Analysis Model ◽  
Element Analysis ◽  
The Difference ◽  
Welding Procedure

In this study, an experimental method has been studied to measure the residual stresses on a specimen with I-groove weldment. The specimens were extracted from I-groove weldment which was joined by SAW (Submerged Arc Welding) with CO2 shield gas. A FEA (Finite Element Analysis) model was developed for the estimation of the residual stresses for the specimen. Measurements were carried out using ESPI(Electronic Speckle Pattern Interferometry) system which can measure the strain distribution on the surface of specimen. The residual stresses were estimated by the value of strain measured by ESPI system. Strain gages were added to evaluate the accuracy of ESPI system. In addition, a three-dimensional FE model was used to estimate the residual stresses generated by the welding procedure. A thermal elasto-plastic analysis was performed by the FEA. The stresses measured by the experiments were compared with the results of FEA. Also, discussed are the difference and agreement between the stresses obtained by experiments and FEA, respectively.

Residual Stresses in Bimetallic Weld Joint With Varying Buttering Layer Thickness

2018 ◽  
Author(s):  
Rahul Chhibber ◽  
Navneet Arora ◽  
B. K. Dutta
Keyword(s):  
Residual Stresses ◽  
Layer Thickness ◽  
Weld Joint ◽  
Ferritic Steel ◽  
Nuclear Energy ◽  
Nuclear Reactors ◽  
Hole Drilling ◽  
Surface Residual Stresses ◽  
Drilling Technique ◽  
304 Austenitic Stainless Steel

The use of bimetallic weld joints is widespread in thermal and nuclear energy generation. It is evident from literature survey that the weld and ferritic steel HAZ region of bimetallic joints are prone to failures. The failures can be attributed to the generation of residual stresses in bimetallic welds. A typical bimetallic weld joint, representing a joint being tested for use in Indian Nuclear Reactors was fabricated between SA 516 Grade 65 and 304 austenitic stainless steel with and without the use of SS 309 L buttering layer. The buttering layer thickness was varied and surface and subsurface residual stresses were assessed using the hole drilling technique and neutron diffraction measurements. It was found that the SS 309 L buttering layer with thickness of around 6 mm employed in the bimetallic weld joint reduces the surface and sub-surface residual stresses in the critical region (ferritic steel HAZ) of the bimetallic weld joint.

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