An Experimental Study on Improved Production Process of Large-Diameter Cylinder Assembly

2013 ◽  
Vol 427-429 ◽  
pp. 200-203
Author(s):  
Hui Fan Zeng
Keyword(s):  
Residual Stress ◽  
Large Diameter ◽  
Aging Treatment ◽  
Dimensional Accuracy ◽  
Welding Residual Stress ◽  
Production Cycle ◽  
Welding Deformation ◽  
Residual Stress State ◽  
Deformation Law ◽  
Large Cylinder

Post-welding annealing and aging treatment are commonly used to reduce welding residual stress and post-welding deformation. However, both show their limited effect in the application of large workpieces. Present study attempts to explore the residual stress state and post-welding deformation law of large workpieces by improving the production technology of the important workpieces of certain engineering equipment a large cylinder assembly. It is proposed that the deformation induced by post-welding residual stress can be effectively compensated by increasing the dimensional accuracy in cutting processing. In this way, aging process is replaced and qualified products can be obtained in a much shorter production cycle.

Effect of Misalignment and Weld Induced Residual Stresses on the Local Buckling Response of Pipelines

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Aiman Al-Showaiter ◽  
Farid Taheri ◽  
Shawn Kenny
Keyword(s):  
Residual Stress ◽  
Stress State ◽  
Residual Stresses ◽  
Oil And Gas ◽  
Local Buckling ◽  
Welding Residual Stress ◽  
Combined Stress ◽  
Residual Stress State ◽  
Girth Welding ◽  
Welding Processes

The aim of the present study is to develop numerical modeling procedures to simulate and study the effect of girth weld induced residual stresses and geometric imperfections on the behavior of conventional carbon steel oil and gas pipelines. The effect of welding residual stresses was obtained through computational simulations of the multipass girth weld process. The numerical procedures were calibrated using available pubic domain data on stainless steel. The methodology for conducting the welding simulation is presented. A parametric analysis was conducted using the finite element methods to evaluate the effects of welding residual stress due to girth welding processes, joint-to-joint misalignment associated with the girth weld, internal pressure, axial force, and diameter to wall thickness ratio on the local buckling response of pipelines. The pipeline moment-curvature response was examined to determine the influence of these parameters. For the parameters investigated, results from this study have demonstrated the significance of residual stress state due to welding processes and girth weld misalignment on the local buckling response of pipelines subjected to monotonic loading with combined stress state.

Welding Residual Stress in a Large Diameter Nuclear Reactor Pressure Vessel Nozzle

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Tao Zhang ◽  
Frederick W. Brust ◽  
Gery Wilkowski ◽  
Heqin Xu ◽  
Alfredo A. Betervide ◽  
...  
Keyword(s):  
Residual Stress ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Pressure Vessel ◽  
Nuclear Power ◽  
Large Diameter ◽  
Reactor Pressure Vessel ◽  
Welding Residual Stress ◽  
Stress Fields ◽  
Reactor Pressure

The Atucha II nuclear power plant is a pressurized heavy water reactor (PHWR) being constructed in Argentina. The original plant was designed by Kraftwerk Union (KWU) in the 1970’s using the German methodology of break preclusion. The plant construction was halted for several decades, but a recent need for power was the driver for restarting the construction. Welding residual stresses in nuclear power plant piping can lead to cracking concerns later in the life of the plant, especially for stress-corrosion cracking. Hence, understanding the residual stress distribution from welding is important to evaluate the reliability of pipe and nozzle joints with welds. In this paper, a large-diameter reactor pressure vessel (RPV) hot-leg nozzle was analyzed. This is a nozzle from Atucha II nuclear power plant in Argentina. The main piping material is 20MnMoNi55 with Tenacito 65R weld metal, and inner diameter (ID) welded cladding at the girth weld locations is made of 309L. The special materials and weld geometry will lead interesting welding residual stress fields. In addition, postweld heat treatment (PWHT) of the girth welds and its boundary conditions could also play an important role in determining welding residual stress fields at the plant’s normal operating conditions. Sensitivity analyses were conducted and the technical observations and comments are provided.

Welding Residual Stress in a Large Diameter Nuclear Reactor Pressure Vessel Nozzle

2012 ◽  
Author(s):  
Tao Zhang ◽  
Frederick W. Brust ◽  
Gery Wilkowski ◽  
Heqin Xu ◽  
Alfredo A. Betervide ◽  
...  
Keyword(s):  
Residual Stress ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Pressure Vessel ◽  
Nuclear Power ◽  
Large Diameter ◽  
Reactor Pressure Vessel ◽  
Welding Residual Stress ◽  
Sensitivity Analyses ◽  
Reactor Pressure

The Atucha II nuclear power plant is a pressurized heavy water reactor being constructed in Argentina. The original plant was designed by KWU in the 1970’s using the German methodology of break preclusion. The plant construction was halted for several decades, but a recent need for power was the driver for restarting the construction. Many times welding residual stresses in nuclear power plant can lead to cracking concerns. Hence, understanding the residual stress distribution is important to evaluate the reliability of pipe and nozzle joints with welds. In this paper, a large diameter Reactor Pressure Vessel (RPV) hot-leg nozzle was analyzed. This is a nozzle from Atucha II nuclear power plant in Argentina. The main weld material is 20MnMoNi55 and ID welded cladding is made of 309L. The special materials and weld geometry will lead to interesting welding residual stress field. In addition, post-weld heat treatment (PWHT) region and boundary conditions could also play an important role in determining welding residual stress fields. Sensitivity analyses were conducted and the technical observation and comments will conclude the paper.

Numerical Simulation and Optimization of the YKK355-4 Motor Shaft Welding Structure

2012 ◽  
Vol 442 ◽  
pp. 134-138
Author(s):  
Yi Xin Shi ◽  
Yu Long Shen ◽  
Wen Hui Pan ◽  
Ji Pu Liu
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Residual Stress ◽  
Welding Process ◽  
Welding Residual Stress ◽  
Welding Deformation ◽  
Welding Quality ◽  
Motor Shaft ◽  
Simulation And Optimization ◽  
Actual Use

Motor shaft is an important component of the electromotor. In the process of motor shaft producing, the motor shaft and the rib plates are usually connected by welding. While in actual use, the structure of the motor shaft may often fracture as a result of the welding, in order to solve the above problem, the structure of YKK355-4 motor shaft and rib plates are modeled and analyzed by using finite element method, and then an optimization on the welding process and shaft structure is performed. By comparison, it is safe to conclude that the welding on both sides at the same time can reduce obviously the welding residual stress and welding deformation and the overall welding quality can be effectively enhanced under the adoption of a 3mm chamfer transition in the connection.

Study on the Evolution of Welding Residual Stress under Tension Loading Condition

2007 ◽  
Vol 353-358 ◽  
pp. 2085-2087
Author(s):  
Ji Tai Niu ◽  
Cheng Jin ◽  
Shi Yu He
Keyword(s):  
Residual Stress ◽  
Local Strain ◽  
Central Line ◽  
Welding Residual Stress ◽  
Hole Drilling ◽  
Hole Drilling Method ◽  
Residual Stress State ◽  
Before And After ◽  
5A06 Aluminum Alloy ◽  
Tension Loading

In this paper, the welding residual stress state and the distribution of 5A06 aluminum alloy welded plate were determined before and after tension loading by means of hole-drilling method. Results show that the applied load can reduce the residual stress obviously and drive it to an even state. But the local strain near the weld is higher than other positions far from the welding central line relatively.

Simulation of Welding Deformation and Residual Stress

2015 ◽  
Vol 84 (1) ◽  
pp. 66-74
Author(s):  
Masahito MOCHIZUKI ◽  
Yoshiki MIKAMI ◽  
Shigetaka OKANO ◽  
Masakazu SHIBAHARA
Keyword(s):  
Residual Stress ◽  
Welding Deformation
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