Residual Stress Concentrations in a Stainless Steel Slot-Weld Measured by the Contour Method and Neutron Diffraction

2009 ◽  
Author(s):  
P. John Bouchard ◽  
Mark Turski ◽  
Mike C. Smith
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Neutron Diffraction ◽  
Structural Integrity ◽  
Measurement Techniques ◽  
Transverse Component ◽  
Contour Method ◽  
Stress Concentrations ◽  
Residual Stress Field ◽  
Concentration Effects

Arc-welding involves the deposition of molten filler metal and the localised input of intense heat. The surrounding parent material and, in the case of multi-pass welds, previously deposited weld metal, undergoes complex thermo-mechanical cycles involving elastic, plastic, creep and viscous deformations. These processes result in the development of large residual stress gradients around the welded region, which can be particularly detrimental to the structural integrity of plant components. The present study examines aggregated weld bead start and stop stress concentration effects in a three pass slot weld specimen that was designed to represent a multi-pass weld repair (without any original weld). The specimen design comprised a Type 316L stainless steel base-plate of nominal dimensions (300 × 200 × 25) mm3 with a 100 mm long by 10 mm deep central slot filled with 3 stringer manual metal arc weld beads, laid one on top of another. Residual stresses in three orthogonal directions were measured by neutron diffraction on a plane cutting through the centre of the plate, parallel to the welding direction, to show concentrations of tensile stress at both the weld start and stop positions. The transverse component of residual stress on the same plane in a second, nominally identical, specimen was mapped using the contour method. By applying two independent measurement techniques the residual stress field within the specimen type was determined with an increased level of confidence. Maximum transverse stress values of about 200 MPa at the weld start position and 300 MPa at the weld stop position were found. Peak tensile stresses in the longitudinal direction of 370 and 460 MPa were measured using neutron diffraction at the weld start and stop positions, respectively. The stresses measured by the contour method and neutron diffraction were in reasonable overall agreement with each other. However, the comparisons pointed to the possible presence of cutting artefacts in the contour results.

Residual Stress Measurement Within a Single Pass Groove Weld Specimen Utilising Neutron Diffraction and the Contour Method

2006 ◽  
Author(s):  
Mark Turski ◽  
Lyndon Edwards ◽  
Jon James ◽  
Peter J. Bouchard ◽  
Mike Smith ◽  
...  
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Stress Measurement ◽  
Welding Process ◽  
Parent Material ◽  
Weld Bead ◽  
Contour Method ◽  
Residual Stress Field ◽  
Full Field ◽  
Longitudinal Residual Stress

This paper describes the measurement of longitudinal residual stresses within a specially designed 200×180×25 mm single groove weld specimen. The purpose of these measurements was to quantify the residual stress field arising from a single stringer weld bead laid down within the constraint of a groove in order to validate finite element simulations of the welding process. Measurements were made over the cross section at the mid-bead length, utilising the relatively new Contour method and neutron diffraction. Non destructive neutron diffraction measurements were made using ENGIN-X, the engineering spectrometer at the ISIS facility of the Rutherford Appleton Laboratory (UK). The Contour method measurement was applied destructively at the Open University (UK), producing a detailed full-field residual stress map. Results from these measurements indicate a peak tensile longitudinal residual stress of ∼300 MPa within the parent material adjacent to the weld bead. Good agreement is found between both techniques.

Residual Stress Measurements in Single and Multi-Pass Groove Weld Specimens Using Neutron Diffraction and the Contour Method

2006 ◽  
Vol 524-525 ◽  
pp. 671-676 ◽  
Author(s):  
M. Kartal ◽  
Mark Turski ◽  
Greg Johnson ◽  
Michael E. Fitzpatrick ◽  
S. Gungor ◽  
...  
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Neutron Diffraction ◽  
Residual Stresses ◽  
Cross Section ◽  
Welding Process ◽  
Contour Method ◽  
Residual Stress Field ◽  
Process Measurements ◽  
Good Agreement

This paper describes the measurement of longitudinal residual stresses within specially designed 200x180x25mm groove weld specimens. The purpose of these measurements was to compare the residual stress field arising from single and multi-pass weld beads laid down within the constraint of a groove in order to validate finite element simulations of the welding process. Measurements were made over the cross section at the mid-bead length, utilising the relatively new Contour method and neutron diffraction. Results from these measurements indicate a larger peak tensile longitudinal residual stresses within the weld region of the multi-pass weld sample. Good agreement is found between both techniques.

A Validated Numerical Model for Residual Stress Predictions in an Eight-Pass-Welded Stainless Steel Plate

2014 ◽  
Vol 777 ◽  
pp. 46-51 ◽  
Author(s):  
Vipulkumar I. Patel ◽  
Ondrej Muránsky ◽  
Cory J. Hamelin ◽  
Mitch D. Olson ◽  
Michael R. Hill ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Stress Field ◽  
Steel Plate ◽  
Fe Analysis ◽  
Contour Method ◽  
Stainless Steel Plate ◽  
Residual Stress Field ◽  
Longitudinal Residual Stress ◽  
Welding Processes

Welding processes create a complex transient state of temperature that results in post-weld residual stresses. The current work presents a finite element (FE) analysis of the residual stress distribution in an eight-pass slot weld, conducted using a 316L austenitic stainless steel plate with 308L stainless steel filler metal. A thermal FE model is used to calibrate the transient thermal profile applied during the welding process. Time-resolved body heat flux data from this model is then used in a mechanical FE analysis to predict the resultant post-weld residual stress field. The mechanical analysis made use of the Lemaitre-Chaboche mixed isotropic-kinematic work-hardening model to accurately capture the constitutive response of the 316L weldment during the simulated multi-pass weld process, which results in an applied cyclic thermo-mechanical loading. The analysis is validated by contour method measurements performed on a representative weld specimen. Reasonable agreement between the predicted longitudinal residual stress field and contour measurement is observed, giving confidence in the results of measurements and FE weld model presented.

Slitting and Contour Method Residual Stress Measurements in an Edge Welded Beam

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Foroogh Hosseinzadeh ◽  
Muhammed Burak Toparli ◽  
Peter John Bouchard
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Structural Integrity ◽  
Stress Measurement ◽  
Welding Process ◽  
Pressure Vessels ◽  
Contour Method ◽  
Residual Stress Field ◽  
Integrity Assessment ◽  
Stress Measurements

Welding is known to introduce complex three-dimensional residual stresses of substantial magnitude into pressure vessels and pipe-work. For safety-critical components, where welded joints are not stress-relieved, it can be of vital importance to quantify the residual stress field with high certainty in order to perform a reliable structural integrity assessment. Finite element modeling approaches are being increasingly employed by engineers to predict welding residual stresses. However, such predictions are challenging owing to the innate complexity of the welding process (Hurrell et al., Development of Weld Modelling Guidelines in the UK, Proceedings of the ASME Pressure Vessels and Piping Conference, Prague, Czech Republic, July 26–30, 2009, pp. 481–489). The idea of creating weld residual stress benchmarks against which the performance of weld modeling procedures and practitioners can be evaluated is gaining increasing acceptance. A stainless steel beam 50 mm deep by 10 mm wide, autogenously welded along the 10 mm edge, is a candidate residual stress simulation benchmark specimen that has been studied analytically and for which neutron and synchrotron diffraction residual stress measurements are available. The current research was initiated to provide additional experimental residual stress data for the edge-welded beam by applying, in tandem, the slitting and contour residual stress measurement methods. The contour and slitting results were found to be in excellent agreement with each other and correlated closely with published neutron and synchrotron residual stress measurements when differences in gauge volume and shape were accounted for.

Slitting and Contour Method Residual Stress Measurements in an Edge Welded Beam

2010 ◽  
Author(s):  
Foroogh Hosseinzadeh ◽  
P. John Bouchard ◽  
M. Burak Toparli
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Structural Integrity ◽  
Stress Measurement ◽  
Welding Process ◽  
Pressure Vessels ◽  
Contour Method ◽  
Residual Stress Field ◽  
Integrity Assessment ◽  
Stress Measurements

Welding is known to introduce complex three-dimensional residual stresses of substantial magnitude into pressure vessels and pipe-work. For safety-critical components, where welded joints are not stress-relieved, it can be of vital importance to quantify the residual stress field with high certainty in order to perform a reliable structural integrity assessment. Finite element modeling approaches are being increasingly employed by engineers to predict welding residual stresses. However, such predictions are challenging owing to the innate complexity of the welding process [1]. The idea of creating weld residual stress benchmarks against which the performance of weld modeling procedures and practitioners can be evaluated is gaining increasing acceptance. A stainless steel beam 50 mm deep by 10 mm wide, autogenously welded along the 10 mm edge, is a candidate residual stress simulation benchmark specimen that has been studied analytically and for which neutron and synchrotron diffraction residual stress measurements are available. The current research was initiated to provide additional experimental residual stress data for the edge-welded beam by applying, in tandem, the slitting and contour residual stress measurement methods. The contour and slitting results were found to be in excellent agreement with each other and correlated closely with published neutron and synchrotron residual stress measurements when differences in gauge volume and shape were accounted for.

Residual Stress Evaluation of Ni Based Weld Metal Using Neutron Diffraction Method

2006 ◽  
Vol 524-525 ◽  
pp. 697-702 ◽  
Author(s):  
Shinobu Okido ◽  
Hiroshi Suzuki ◽  
K. Saito
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Neutron Diffraction ◽  
Weld Metal ◽  
Diffraction Method ◽  
Fem Analysis ◽  
Butt Weld ◽  
Stress Evaluation ◽  
Neutron Diffraction Method

Residual stress generated in Type-316 austenitic stainless steel butt-weld jointed by Inconel-182 was measured using a neutron diffraction method and compared with values calculated using FEM analysis. The measured values of Type-316 austenitic stainless steel as base material agreed well with the calculated ones. The diffraction had high intensity and a sharp profile in the base metal. However, it was difficult to measure the residual stress at the weld metal due to very weak diffraction intensities. This phenomenon was caused by the texture in the weld material generated during the weld procedure. As a result, this texture induced an inaccurate evaluation of the residual stress. Procedures for residual stress evaluation to solve this textured material problem are discussed in this paper. As a method for stress evaluation, the measured strains obtained from a different diffraction plane with strong intensity were modified with the ratio of the individual elastic constant. The values of residual stress obtained using this method were almost the same as those of the standard method using Hooke’s law. Also, these residual stress values agreed roughly with those from the FEM analysis. This evaluation method is effective for measured samples with a strong texture like Ni-based weld metal.

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.

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