![Page 1: Welding simulations: assessment of welding residual](https://reader030.vdocuments.site/reader030/viewer/2022012500/617907a49e181c65b15d0a27/html5/thumbnails/1.jpg)
Welding simulations: assessment of welding
residual stresses and post weld heat treatment
Etienne Bonnaud and Jens Gunnars, Inspecta Technology AB
2016-09-281
Third Nordic Conference on Design and Fabrication of Welded Structures, 2016-09-29, Stockholm
![Page 2: Welding simulations: assessment of welding residual](https://reader030.vdocuments.site/reader030/viewer/2022012500/617907a49e181c65b15d0a27/html5/thumbnails/2.jpg)
Outline
2
Presentation of Inspecta
Overview of welding simulations
Case study 1: Pressure Vessel manufacture
• Bending before welding
• Welding before bending
Case study 2: Core Shroud Support of a Nuclear Power Plant
• Comparison between simulations and measurements
• Influence of Post Weld Heat Treatment
Case study 3: Two-stroke diesel engine support plate
• Root failure
• Influence of Post Weld Heat Treatment
Conclusion
2016-09-28
![Page 3: Welding simulations: assessment of welding residual](https://reader030.vdocuments.site/reader030/viewer/2022012500/617907a49e181c65b15d0a27/html5/thumbnails/3.jpg)
2016-09-283
Inspecta Group
Industries Thermal Power & Heating, Renewables, Nuclear Power,
Oil & Gas, Chemical, Pulp & Paper, Metals & Mining,
Manufacturing, Rail, Ports, Infrastructure, Real Estate
Service areasInspection, Certification, Testing, Design Review,
Quality Assurance, Revisions & Outages, Risk Management,
Advisory & Consultancy, Asset Integrity Engineering,
Advanced NDT, Life Time & Aging Management,
Contract R&D, Training
Countries Sweden, Finland, Norway, Denmark,
Poland, Estonia, Latvia, Lithuania
Revenue 200 MEUR
Employees 1600 engineers
Offices 80
![Page 4: Welding simulations: assessment of welding residual](https://reader030.vdocuments.site/reader030/viewer/2022012500/617907a49e181c65b15d0a27/html5/thumbnails/4.jpg)
2016-09-284
■ Main Competence Areas:
• Solid mechanics and structural integrity
• Materials technology, corrosion and welding
• Risk assessment and project management
■ Services Areas
• Design verification and optimization, design verification to codes and standards
• Structural and fatigue analysis, fracture mechanics, plasticity, buckling, dynamics
• Asset Integrity Engineering
• Inspection planning, corrosion management, in-depth degradation assessments
• Risk based inspection planning (RBI), Non-Intrusive Inspection (NII)
• Fitness-for-service (FFS) evaluation of defects and damage found at revisions
• Component life assessments, Life time extension strategies, structural integrity
• Project management
• Risk, reliability and safety assessments
• Welding technology, welding simulation
• Quality assurance, NDT requirements
• Contract R&D
Inspecta TECH – Advisory & Consultancy
![Page 5: Welding simulations: assessment of welding residual](https://reader030.vdocuments.site/reader030/viewer/2022012500/617907a49e181c65b15d0a27/html5/thumbnails/5.jpg)
Outline
5
Presentation of Inspecta
Overview of welding simulations
Case study 1: Pressure Vessel manufacture
• Bending before welding
• Welding before bending
Case study 2: Core Shroud Support of a Nuclear Power Plant
• Comparison between simulations and measurements
• Influence of Post Weld Heat Treatment
Case study 3: Two-stroke diesel engine support plate
• Root failure
• Influence of Post Weld Heat Treatment
Conclusion
2016-09-28
![Page 6: Welding simulations: assessment of welding residual](https://reader030.vdocuments.site/reader030/viewer/2022012500/617907a49e181c65b15d0a27/html5/thumbnails/6.jpg)
Background – Weld Residual Stresses
Effects from welding processes:
- rapid heating and cooling cycles
- material submitted to compression and tension
- solidification and high temperatures
- effects from boundary conditions
- large plastic strains
- residual stresses arise - compressive and tensile
Consequences for component reliability:
increased hazard for
- stress corrosion cracking
- fatigue
- fracture
6 2016-09-28
![Page 7: Welding simulations: assessment of welding residual](https://reader030.vdocuments.site/reader030/viewer/2022012500/617907a49e181c65b15d0a27/html5/thumbnails/7.jpg)
Background – Weld Residual Stresses Measurements
7
Destructive methods – relaxation techniques:
• Hole drilling and measurement by strain gauge
• Incremental Deep Hole Drilling (IDHD) technique
• Contour method
• Slitting, Layer removal
Uncertainty in all methods is >20% in challenging cases
and assumptions for evaluation
Non-destructive methods – diffraction techniques:
• Neutron diffraction
• X-ray diffraction (standard, synchrotron high energy)
Research: Ultrasonic methods, magnetic methods
2016-09-28
![Page 8: Welding simulations: assessment of welding residual](https://reader030.vdocuments.site/reader030/viewer/2022012500/617907a49e181c65b15d0a27/html5/thumbnails/8.jpg)
Background – Weld Residual Stresses Modelling
Weld cross section:
- geometry
- bead size and numbers
Weld residual stresses simulation:
- thermal and mechanical analyses
- axial stress
- areas in compression and in tension
Material has experienced:
- heating and cooling
- compression and tension
- plastic strains
8 2016-09-28
![Page 9: Welding simulations: assessment of welding residual](https://reader030.vdocuments.site/reader030/viewer/2022012500/617907a49e181c65b15d0a27/html5/thumbnails/9.jpg)
Outline
9
Presentation of Inspecta
Overview of welding simulations
Case study 1: Pressure Vessel manufacture
• Bending before welding
• Welding before bending
Case study 2: Core Shroud Support of a Nuclear Power Plant
• Comparison between simulations and measurements
• Influence of Post Weld Heat Treatment
Case study 3: Two-stroke diesel engine support plate
• Root failure
• Influence of Post Weld Heat Treatment
Conclusion
2016-09-28
![Page 10: Welding simulations: assessment of welding residual](https://reader030.vdocuments.site/reader030/viewer/2022012500/617907a49e181c65b15d0a27/html5/thumbnails/10.jpg)
Pressure Vessel – Analysis description
10
Bending downwards
Bending upwards
As welded
2016-09-28
![Page 11: Welding simulations: assessment of welding residual](https://reader030.vdocuments.site/reader030/viewer/2022012500/617907a49e181c65b15d0a27/html5/thumbnails/11.jpg)
Pressure Vessel – Results
11
Bending only
Hoop stress: -205 MPa -> 200 MPa
Welding only
Hoop stress: -301 MPa -> 421 MPa
2016-09-28
![Page 12: Welding simulations: assessment of welding residual](https://reader030.vdocuments.site/reader030/viewer/2022012500/617907a49e181c65b15d0a27/html5/thumbnails/12.jpg)
Pressure Vessel – Results: bending followed by welding
12
Bending Downwards: Hoop stress: -305 MPa -> 421 MPa
Bending Upwards: Hoop stress: -299 MPa -> 421 MPa
2016-09-28
![Page 13: Welding simulations: assessment of welding residual](https://reader030.vdocuments.site/reader030/viewer/2022012500/617907a49e181c65b15d0a27/html5/thumbnails/13.jpg)
Pressure vessel – Results: welding followed by bending
13
Bending Downwards: Hoop stress: -197 MPa -> 195 MPa
Bending Upwards: Hoop stress: -218 MPa -> 219 MPa
2016-09-28
![Page 14: Welding simulations: assessment of welding residual](https://reader030.vdocuments.site/reader030/viewer/2022012500/617907a49e181c65b15d0a27/html5/thumbnails/14.jpg)
Outline
14
Presentation of Inspecta
Overview of welding simulations
Case study 1: Pressure Vessel manufacture
• Bending before welding
• Welding before bending
Case study 2: Core Shroud Support of a Nuclear Power Plant
• Comparison between simulations and measurements
• Influence of Post Weld Heat Treatment
Case study 3: Two-stroke diesel engine support plate
• Root failure
• Influence of Post Weld Heat Treatment
Conclusion
2016-09-28
![Page 15: Welding simulations: assessment of welding residual](https://reader030.vdocuments.site/reader030/viewer/2022012500/617907a49e181c65b15d0a27/html5/thumbnails/15.jpg)
Core Shroud Support – Set up and Model
15 2016-09-28
![Page 16: Welding simulations: assessment of welding residual](https://reader030.vdocuments.site/reader030/viewer/2022012500/617907a49e181c65b15d0a27/html5/thumbnails/16.jpg)
Core Shroud Support – Final Results
16 2016-09-28
Simulation result - field plot
Deep hole drilling measurement
Path plots
![Page 17: Welding simulations: assessment of welding residual](https://reader030.vdocuments.site/reader030/viewer/2022012500/617907a49e181c65b15d0a27/html5/thumbnails/17.jpg)
Core Shroud Support – Post Weld Heat Treatment
17 2016-09-28
• Circumferential stress at room temperature
• After buttering but before attachment weld
• Post Weld Heat treatment according to standards (7 hours at 620ºC)
Important stress release in the Carbon Steel
Before Post Weld Heat Treatment After Post Weld Heat Treatment
![Page 18: Welding simulations: assessment of welding residual](https://reader030.vdocuments.site/reader030/viewer/2022012500/617907a49e181c65b15d0a27/html5/thumbnails/18.jpg)
Outline
18
Presentation of Inspecta
Overview of welding simulations
Case study 1: Pressure Vessel manufacture
• Bending before welding
• Welding before bending
Case study 2: Core Shroud Support of a Nuclear Power Plant
• Comparison between simulations and measurements
• Influence of Post Weld Heat Treatment
Case study 3: Two-stroke diesel engine support plate
• Root failure
• Influence of Post Weld Heat Treatment
Conclusion
2016-09-28
![Page 19: Welding simulations: assessment of welding residual](https://reader030.vdocuments.site/reader030/viewer/2022012500/617907a49e181c65b15d0a27/html5/thumbnails/19.jpg)
Support plate – root failure
2016-09-2819
![Page 20: Welding simulations: assessment of welding residual](https://reader030.vdocuments.site/reader030/viewer/2022012500/617907a49e181c65b15d0a27/html5/thumbnails/20.jpg)
Support plate – Post Weld Heat Treatment
2016-09-2820
![Page 21: Welding simulations: assessment of welding residual](https://reader030.vdocuments.site/reader030/viewer/2022012500/617907a49e181c65b15d0a27/html5/thumbnails/21.jpg)
Conclusions
21
• Weld residual stress simulations give reliable results.
• Very good agreement between simulations and measurements confirms that both simulations and experiments give accurate results.
• Post Weld heat treatment is usually beneficial but can also be detrimental.
• 20 years of experience within weld residual stresses simulations at Inspecta.
2016-09-28
![Page 22: Welding simulations: assessment of welding residual](https://reader030.vdocuments.site/reader030/viewer/2022012500/617907a49e181c65b15d0a27/html5/thumbnails/22.jpg)
Thank you for your attention!
22 2016-09-28
![Page 23: Welding simulations: assessment of welding residual](https://reader030.vdocuments.site/reader030/viewer/2022012500/617907a49e181c65b15d0a27/html5/thumbnails/23.jpg)
2016-09-2823