The Effect of Phase Change Transformation on Residual Stress

93 Pages·2015·3.36 MB·English

by  Bin Yang

Lehigh University
Lehigh Preserve
Teses and Dissertations
2015
Autogenous Welding on a Flat Plate: Te Efect of
Phase Change Transformation on Residual Stress
Bin Yang
Lehigh University
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Yang, Bin, "Autogenous Welding on a Flat Plate: Te Efect of Phase Change Transformation on Residual Stress" (2015).Teses and
Dissertations. Paper 1679.
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Autogenous Welding on a Flat Plate: The Effect of
Phase Change Transformation on Residual Stress

by
Bin Yang

Presented to the Graduate and Research Committee
of Lehigh University
in Candidacy for the Degree of
Master of Science
in
Mechanical Engineering
Lehigh University
2014
This thesis is accepted and approved in partial fulfillment of the requirements for the
Master of Science.

Date

Thesis Advisor

Chairperson of Department

ii
Acknowledgment
The encouragement and advice I received while writing this thesis from Professor
Herman F. Nied must be gratefully acknowledged. Professor Herman F. Nied gave me
much support and constructive comments on my research and thesis. In addition, I
gratefully thank Muhammed Ashraf, Xiao Liu, and Tianyi Luo for helping me with access
to the workstation.

Also, I express my love to my parents and sister.

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Table of Contents
List of Figures vi
List of Tables xi
Abstract 1
Chapter 1. Introduction 2
1.1 Background 2
1.2 Welding simulation with SYSWELD 6
Chapter 2. Welding model 10
2.1 Basic 2-D geometric model 10
2.2 Meshing 13
2.3 Welding model 17
Chapter 3. Welding Simulation 20
3.1 Materials 20
3.2 Defining the welding simulation with Visual-Weld 10.0 22
Chapter 4. Welding simulation results 30
4.1 Heat transfer behavior 30
4.2 Mechanical results for the 316L austenitic stainless steel 34
4.3 Mechanical results for S355J2G3 carbon steel 43
4.4 Metallurgical phase in S355J2G3 carbon steel 52
iv
4.5 Mechanical results for S355J2G3 carbon steel without phase changes 56
Chapter 5. Conclusions 63
Chapter 6. Further work 64
References 65
Appendix 67
VITA 81

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List of Figures
Figure 1.1 SYSWELD’s Visual-Weld 10.0 graphical interface running in Windows. 8
Figure 1.2 Results presented by Visual-Viewer 9
Figure 1.3 Workflow of simulation with Visual-Environment 9
Figure 2.1 Dimensions of flat plate 10
Figure 2.2 Cross-sectional view of temperature contours in the flat plate 11
Figure 2.3 2-D geometric model of flat plate 12
Figure 2.4 Residual stresses on the top surface of flat plate 14
Figure 2.5 Window of checking coincident nodes 14
Figure 2.6 Final finite element model of flat plate 15
Figure 2.7 Detailed meshes near melting zone 15
Figure 2.8 Defining load of welding model 17
Figure 2.9 Defining collectors for the clamping boundary conditions 18
Figure 2.10 Defining welding path 19
Figure 2.11 Final welding model 19
Figure 3.1 Setting up project details 22
Figure 3.2 Defining global parameter 23
Figure 3.3 Setting up materials of components and joints 23
Figure 3.4 Defining welding process 24
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Figure 3.5 Setting up cooling boundary condition 25
Figure 3.6 Defining boundary conditions 26
Figure 3.7 Unclamped condition during the entire welding process 27
Figure 3.8 Before release of clamped condition 28
Figure 3.9 After release of clamped condition 28
Figure 3.10 Setting up solution parameter 29
Figure 4.1 Temperature contours of 316L: (a) t=1.264s, (b) t=2.528s, (c) t=3.160s, and (d)
t=5.000s. 30
Figure 4.2 Distributions of temperature on top surface of flat plate for 316L 31
Figure 4.3 Temperature contours of S355J2G3: (a) t=1.264s, (b) t=2.528s, (c) t=3.160s,
and (d) t=5.000s. 32
Figure 4.4 Distributions of temperature on top surface of flat plate for S355J2G3 33
Figure 4.5 𝜎
𝑥𝑥 stress component at two different times for 316L. (a) t=5s, (b) t=600s. 35
Figure 4.6 𝜎
𝑥𝑥 stress component at two different times for 316L. (a) t=3600s, (b) t=3601s
(all clamping restraints removed) 36
Figure 4.7 Distributions of displacement on bottom-plane for 316L 37
Figure 4.8 Distribution of residual stresses on top surface for 316L 38
Figure 4.9 Position of maximum radius of welding zone 39
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Figure 4.10 Distributions of the 𝜎
𝑟𝑟 and 𝜎𝜃𝜃 stress components along maximum radius of
welding zone for 316L. (a) boundary condition 2, (b) boundary condition 3, (c) comparison
of 𝜎𝑟𝑟, (d) comparison of 𝜎𝜃𝜃. 40
Figure 4.11 Comparison of residual stresses on top surface for 316L under different
boundary conditions 41
Figure 4.12 Comparison of residual stresses on maximum radius of welding zone for 316L
under different boundary conditions 42
Figure 4.13 𝜎𝑥𝑥 stress component at two different times for S355J2G3. (a) t=5s, (b) t=600s.
44
Figure 4.14 𝜎𝑥𝑥 stress component at two different times for S355J2G3. (a) t=3600s, (b)
t=3601s. 45
Figure 4.15 Distributions of displacement on bottom-plane for S355J2G3 46
Figure 4.16 Distribution of residual stresses on top surface for S355J2G3 47
Figure 4.17 Distributions of the 𝜎
𝑟𝑟 and 𝜎𝜃𝜃 stress components along maximum radius of
welding zone for S355J2G3. (a) boundary condition 2, (b) boundary condition 3, (c)
comparison of 𝜎
𝑟𝑟, (d) comparison of 𝜎𝜃𝜃. 48
Figure 4.18 Comparison of residual stresses on top surface for S355J2G3 under different
boundary conditions 49
Figure 4.19 Comparison of residual stresses on maximum radius of welding zone for
S355J2G3 under different boundary conditions 50
Figure 4.20 Comparison of different residual stresses for 316L and S355J2G3 51
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Figure 4.21 Austenite distribution along top surface at 5s during welding 53
Figure 4.22 Ferrite distribution along top surface after cooling 53
Figure 4.23 Bainite distribution along top surface after cooling 54
Figure 4.24 Martensite distribution along top surface after cooling 54
Figure 4.25 Phase distribution along top surface 55
Figure 4.26 Distributions of residual stresses on top surface under boundary condition 1
for S355J2G3 without phase changes 56
Figure 4.27 Distributions of residual stresses on top surface under boundary condition 2
for S355J2G3 without phase changes 57
Figure 4.28 Distributions of residual stresses on top surface under boundary condition 3
for S355J2G3 without phase changes 58
Figure 4.29 Distributions of residual stresses on top surface for S355J2G3 without phase
changes 58
Figure 4.30 Distributions of residual stresses on top surface under boundary condition 1 59
Figure 4.31 Distributions of residual stresses on top surface under boundary condition 2 60
Figure 4.32 Distributions of residual stresses on top surface under boundary condition 3 60
Figure 4.33 Distributions of residual tresses on maximum radius of welding zone under
boundary condition 1 61
Figure 4.34 Distributions of residual tresses on maximum radius of welding zone under
boundary condition 2 62
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