scholarly journals Effects of Weld and Post Weld Heat Treatment Conditions on Welding Residual Stress in Low Alloy Steel Plate

2013 ◽  
Vol 79 (802) ◽  
pp. 847-862 ◽  
Author(s):  
Nobuyoshi YANAGIDA ◽  
Koichi SAITO
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Alloy Steel ◽  
Steel Plate ◽  
Post Weld Heat Treatment ◽  
Welding Residual Stress ◽  
Low Alloy Steel ◽  
Treatment Conditions ◽  
Weld Heat

Residual Stress Analysis of Bead Welded Low Alloy Steel Plate Specimens Subjected to Post Weld Heat Treatment

2011 ◽  
Author(s):  
Nobuyoshi Yanagida ◽  
Koichi Saito
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Phase Transformation ◽  
Stress Analysis ◽  
Alloy Steel ◽  
Steel Plate ◽  
Post Weld Heat Treatment ◽  
Welding Residual Stress ◽  
Low Alloy Steel ◽  
Residual Stress Analysis

We developed a residual stress analysis method for bead welded low alloy steel JIS SQV2A (equivalent to ASTM A533B cl. 1) plates subjected to post weld heat treatment (PWHT). Two specimens were fabricated; each was a bead welded low alloy steel plate. One was in the as-welded condition (as-welded specimen) and the other was subjected to PWHT at 625°C (PWHT specimen). Strain gauges were used to measure the distributions of the residual stress in these specimens. The measurement data showed that the longitudinal stress at the center of a bead was 0 MPa and that in the heat-affected zone was 100 MPa. The transverse stress at the center of a bead was 200 MPa in the as-welded specimen. The absolute residual stress was decreased to less than 50 MPa for the PWHT specimen. We conducted finite element analyses to predict the distributions of welding residual stress in these specimens. The amount of phase transformation strain in low alloy steel was taken into account in the welding residual stress analysis, and creep strain was taken into account in the stress mitigation analysis. The results from the analyses agree well with the experimental results. These findings prove that welding residual stress can be simulated during a thermal elastic plastic (TEP) analysis by conducting a phase transformation and taking the generation of creep strain in the PWHT samples into consideration can be used to simulate that stress mitigation.

Alternative Approach for Qualification of Temperbead Welding in the Nuclear Industry

2012 ◽  
Author(s):  
Steven L. McCracken ◽  
Richard E. Smith
Keyword(s):  
Heat Treatment ◽  
Fracture Toughness ◽  
Alloy Steel ◽  
Nuclear Power ◽  
Post Weld Heat Treatment ◽  
Nuclear Power Industry ◽  
Low Alloy Steels ◽  
Low Alloy Steel ◽  
Alloy Steels ◽  
Weld Heat

Temperbead welding is common practice in the nuclear power industry for in-situ repair of quenched and tempered low alloy steels where post weld heat treatment is impractical. The temperbead process controls the heat input such that the weld heat-affected-zone (HAZ) in the low alloy steel is tempered by the welding heat of subsequent layers. This tempering eliminates the need for post weld heat treatment (PWHT). Unfortunately, repair organizations in the nuclear power industry are experiencing difficulty when attempting to qualify temperbead welding procedures on new quenched and tempered low alloy steel base materials manufactured to modern melting and deoxidation practices. The current ASME Code methodology and protocol for verification of adequate fracture toughness in materials was developed in the early 1970s. This paper reviews typical temperbead qualification results for vintage heats of quenched and tempered low alloy steels and compares them to similar test results obtained with modern materials of the same specification exhibiting superior fracture toughness.

Investigation of effect of post weld heat treatment conditions on residual stress for ITER blanket shield blocks

2016 ◽  
Vol 109-111 ◽  
pp. 747-751 ◽  
Author(s):  
Hun-Chea Jung ◽  
Sa-Woong Kim ◽  
Yun-Hee Lee ◽  
Seung-Wook Baek ◽  
Min-Su Ha ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Post Weld Heat Treatment ◽  
Treatment Conditions ◽  
Weld Heat

scholarly journals Effect of Post-Weld Heat Treatment Conditions on Mechanical Properties, Microstructures and Nonductile Fracture Behavior of SA508 Gr.1a Thick Weldments

2021 ◽  
Author(s):  
Junsang Lee ◽  
Jong Sung Kim ◽  
Bongsang Lee ◽  
Sungwoo Cho ◽  
Dongil Kwon ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Residual Stress ◽  
Arc Welding ◽  
Post Weld Heat Treatment ◽  
Operating Conditions ◽  
Bend Test ◽  
Welding Residual Stress ◽  
Uniaxial Tensile ◽  
Weld Heat

AbstractThis study analyzes the effects of post-weld heat treatment (PWHT) on the mechanical properties and microstructures of SA-508 Gr.1a welds and proposes a new PWHT exemption criterion based on nonductile fracture evaluation considering welding residual stress. The welding coupons were prepared with submerged-arc welding, gas-tungsten arc welding, and shielded-metal arc welding, using ferritic steel, SA-508 Gr.1a. The microstructure of the heat-affected zone (HAZ) was analyzed using optical microscopy, electron-back-scatter diffraction and Vickers hardness testing. The mechanical properties of the welds were evaluated by uniaxial tensile test, transverse side bend test, Charpy V-notch impact test and side bend test. Bainite and ferrite structures formed mainly in the HAZ, and the grain size became coarser with proximity to the surface and fusion line. The mechanical properties did not depend strongly on PWHT, weldment thickness or welding techniques, and they satisfied the welding procedure qualification test specified in the ASME Boiler & Pressure Vessel code. Welding residual stresses were considered in assessing structural integrity using nonductile fracture evaluation. A margin of safety against nonductile fracture with residual stress was calculated for Korean Standard Nuclear Power Plant steam-generator welds, using its design parameters and operating conditions, and this safety margin is suggested as an acceptance criterion for residual stress for exemption from PWHT. Graphic abstract

Effects of Post-Weld Heat Treatment on the Microstructure and Toughness of Flash Butt Welded High-Strength Low-Alloy Steel

2018 ◽  
Vol 49 (4) ◽  
pp. 1276-1286 ◽  
Author(s):  
Nikhil Shajan ◽  
Kanwer Singh Arora ◽  
Brajesh Asati ◽  
Vikram Sharma ◽  
Mahadev Shome
Keyword(s):  
Heat Treatment ◽  
Alloy Steel ◽  
High Strength ◽  
Post Weld Heat Treatment ◽  
Low Alloy Steel ◽  
Weld Heat

Creep Property Evaluation for Stress Mitigation Simulation in Post Weld Heat Treatment

2013 ◽  
Author(s):  
Nobuyoshi Yanagida ◽  
Koichi Saito
Keyword(s):  
Heat Treatment ◽  
Stress Relaxation ◽  
Creep Strain ◽  
Alloy Steel ◽  
Creep Property ◽  
Post Weld Heat Treatment ◽  
Low Alloy Steel ◽  
Creep Tests ◽  
Material Parameters ◽  
Weld Heat

Creep properties for stress mitigation simulation in post weld heat treatment (PWHT) were studied. Materials tested in this study were both deposited metal and base metal of a nickel base alloy, an austenitic stainless steel, and a low alloy steel. First, creep tests were conducted at 625 °C, which is a holding temperature in PWHT of a low alloy steel. Test specimens were subjected to certain stress and the amount of creep strain was measured. A Norton-Bailey law model was used to simulate the amount of creep strain. Material parameters for the Norton-Bailey law model were determined from the creep strain measurement data. Stress relaxation tests were also conducted at 625 °C. Test specimens were subjected to a constant total strain and stress relaxation was measured. The experimentally measured stress relaxation data were calculated using the Norton-Bailey law model with the material parameters determined from the creep tests. The calculation data showed good agreement with the experiment data. Accordingly, the material parameters determined in this study can be considered valid.

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