scholarly journals The Effect of Welding-Pass Grouping on the Prediction Accuracy of Residual Stress in Multipass Butt Welding

2017 ◽  
Vol 2017 ◽  
pp. 1-13
Author(s):  
Jeongung Park ◽  
Gyubaek An ◽  
Sunghoon Kim
Keyword(s):  
Residual Stress ◽  
Diffraction Method ◽  
Fe Analysis ◽  
Computer Memory ◽  
Butt Weld ◽  
Butt Welding ◽  
Welded Structure ◽  
Welding Sequence ◽  
Grouping Method ◽  
Neutron Diffraction Method

The residual stress analysis of a thick welded structure requires a lot of time and computer memory, which are different from those in thin welded structure analysis. This study investigated the effect of residual stress due to welding-pass grouping as a way to reduce the analysis time in multipass thick butt welding joint. For this purpose, the parametric analysis which changes the number of grouping passes was conducted in the multipass butt weld of a structure with a thickness of 25 mm and 70 mm. In addition, the residual stress by thermal elastoplastic FE analysis is compared with the results by the neutron diffraction method for verifying the reliability of the FE analysis. The welding sequence is considered in order to predict the residual stress more accurately when using welding-pass grouping method. The results of the welding-pass grouping model and half model occurred between the results of the left/right of the full model. If the total number of welding-pass grouping is less than half of that of welding pass, a large difference with real residual stress is found. Therefore, the total number of the welding-pass grouping should not be reduced to more than half.

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.

Investigation of the residual stress in UO2-Mo composites via a neutron diffraction method

2020 ◽  
Vol 46 (10) ◽  
pp. 15889-15896 ◽  
Author(s):  
Liang Cheng ◽  
Rui Gao ◽  
Biaojie Yan ◽  
Changsheng Zhang ◽  
Ruiwen Li ◽  
...  
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Diffraction Method ◽  
Neutron Diffraction Method

scholarly journals Comparison of Measured Residual Stress Distributions in Extra-Thick Butt Welds Joined by One-Pass EGW and Multipass FCAW

2014 ◽  
Vol 6 ◽  
pp. 861247 ◽  
Author(s):  
Jeong-Ung Park ◽  
GyuBaek An ◽  
Wan Chuck Woo ◽  
Jae-hyouk Choi ◽  
Ninshu Ma
Keyword(s):  
Residual Stress ◽  
Arc Welding ◽  
Electron Gas ◽  
Diffraction Method ◽  
Stress Distributions ◽  
Flux Cored Arc Welding ◽  
Longitudinal Residual Stress ◽  
Inherent Strain ◽  
Inherent Strain Method ◽  
Neutron Diffraction Method

This study is to measure the welding residual stress distributions in a 70 mm-thick butt weld by one-pass electron gas welding using both the inherent strain method and neutron diffraction method, respectively. Based on the measurement results, the characteristics of residual stress distribution through thickness were compared between one-pass electron gas welding and multipass flux-cored arc welding. Residual stresses in the specimens of electron gas welding measured by the inherent strain method and neutron diffraction method were well matched. The longitudinal residual stress in the multi-pass flux-cored arc welding is tensile through all thicknesses in the welding fusion zone. Meanwhile, longitudinal residual stress in electron gas welding is tensile on both surfaces and compressive at the inside of the plate. The magnitude of residual stresses due to electron gas welding is lower than that due to flux-cored arc welding.

A Study of Redistribution of Residual Stress and Hardness Due to Welding and Surface-Machining at Girth Welded Joint

2009 ◽  
Author(s):  
Masahito Mochizuki ◽  
Jinya Katsuyama ◽  
Ryohei Ihara ◽  
Hiroaki Mori ◽  
Yoshiki Mikami ◽  
...  
Keyword(s):  
Residual Stress ◽  
Nuclear Power ◽  
Power Plants ◽  
Crack Growth Behavior ◽  
Internal Diameter ◽  
Butt Weld ◽  
Butt Welding ◽  
Surface Machining ◽  
Inner Surface ◽  
Before And After

Stress corrosion cracking (SCC) near the welded zone of core internals and recirculation piping of Type 316L stainless steel in BWR nuclear power plants has been observed at the surface where tensile residual stress exists due to welding and/or surface-machining. It is well-known that butt-welding of austenitic piping causes the tensile stress in the inner surface of the pipe and that surface-machining is usually conducted before and after piping butt-welding to match the internal diameter (ID) of pipes and to provide a smooth surface finish but some amount of hardening. The SCCs near the welds of Ni-based alloys have been observed in the environment of primary water coolant, which is so called PWSCC. In this case, both residual stress and hardening are also the most important factors induced by welding as well as surface-machining in the regions of interest. In this work, therefore, Vickers hardness and residual stress distributions at work hardened layer such as inner surface of piping butt-weld by surface-machining before and after welding were experimentally evaluated. A simulation using a local micron-scale finite element method (FEM) model has been performed to support the understanding of experimental data by a model which was proposed in previous paper (PVP2006 and 2008 [1, 2]). Redistribution behavior of residual stress by welding after surface-machining will be discussed based on experimental and analytical results with regard to crack growth behavior.

scholarly journals Residual Stress Measurement of Shrink Fitted Component in Textured Al Alloy by Neutron Diffraction Method

2005 ◽  
Vol 54 (3) ◽  
pp. 333-338 ◽  
Author(s):  
Shinobu OKIDO ◽  
Makoto HAYASHI ◽  
Yoshiaki AKINIWA ◽  
Keisuke TANAKA ◽  
Nobuaki MINAKAWA ◽  
...  
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Stress Measurement ◽  
Diffraction Method ◽  
Residual Stress Measurement ◽  
Al Alloy ◽  
Neutron Diffraction Method
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