A Computational Temperature Analysis for Induction Heating of Welded Pipes

1985 ◽  
Vol 107 (2) ◽  
pp. 148-153 ◽  
Author(s):  
R. L. Koch ◽  
E. F. Rybicki ◽  
R. D. Strattan
Keyword(s):  
Computational Model ◽  
Stress Corrosion ◽  
Induction Heating ◽  
Stress Corrosion Cracking ◽  
Pipe Wall ◽  
Corrosion Cracking ◽  
Heat Sources ◽  
Temperature Dependent ◽  
Compressive Stresses ◽  
Temperature Dependent Properties

Recent approaches to controlling stress corrosion cracking in welded 304 stainless steel pipes have been based on various types of controlled heating procedures. When applied properly, the heating procedure introduces high compressive stresses in region of observed cracking. The compressive stresses are believed to be effective in deterring stress corrosion cracking. One procedure for applying controlled heating to the pipe employs induction heating and is called Induction Heating for Stress Improvement or IHSI. The effective utilization of induction heating requires an understanding of how the induction heating parameters are related to the resulting residual stresses. This paper describes the development of a computational model directed at evaluating the heat densities and temperature distributions for Induction Heating for Stress Improvement (IHSI). The basic mechanism of inducting differs from that of a welding arc in that induction heating produces a distribution of heat sources within the pipe wall while in weld arc heating, the heat source is confined to the surface. Thus the computational model requires two parts. The first part evaluates the induced electrical current and determines the density of heat sources in the pipe wall. The second part of the model uses these heating densities to evaluate the temperature distribution. Temperature dependent properties were found to be important in representing the induction heating phenomenon. However, including temperature dependent properties in the model leads to nonlinear equations which require iterative solution methods for each part of the model. The nonlinear characteristics of the equations also require iterations between the two parts of the model. The model includes the important parameters of the induction heating process and has shown good agreement with temperature data for two different pipe sizes. Because of the inherent nonlinearities in the model and the iterative methods required for general solutions, extensions of the model to improve the algorithimic efficiency are discussed.

Qualification of Induction Heating Stress Improvement for Mitigation of Stress Corrosion Cracking

1982 ◽  
Vol 104 (4) ◽  
pp. 344-350 ◽  
Author(s):  
N. R. Hughes ◽  
T. P. Diaz ◽  
V. V. Pestanas
Keyword(s):  
Stress Corrosion ◽  
Induction Heating ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
X Ray Diffraction ◽  
Axial Loads ◽  
Intergranular Stress Corrosion ◽  
Compressive Stresses ◽  
Intergranular Stress Corrosion Cracking ◽  
Compressive Residual Stresses

This paper describes the efforts toward qualification of induction heating stress improvement (IHSI) for mitigation of intergranular stress corrosion cracking (IGSCC) in Boiling Water Reactor (BWR) piping. The IHSI process, which is applied to piping after it is fully erected, produces compressive residual stresses on the pipe inside surface in the vicinity of the weld heat affected zone (HAZ). The creation of these compressive stresses has been confirmed by surface and through-wall strain gage and X-ray diffraction residual stress measurements on 4, 10, and 16-in. dia Schedule 80 welded and IHSI treated pipes. Confirmation of increased resistance to IGSCC due to the IHSI process has been accomplished by full-sized 4-in-dia pipe tests in General Electric’s Pipe Test Laboratory. The pipe test utilized an environment of oxygenated high-purity water at 288°C (550°F). Axial loads were applied which exceeded the material 288°C yield strength.

Investigation of the Influence of Shot Peening on Stress Corrosion Cracking of Stainless Steel Welded Joints

2008 ◽  
Vol 575-578 ◽  
pp. 672-677 ◽  
Author(s):  
Xiang Ling ◽  
Hong Fang Ni ◽  
Gang Ma
Keyword(s):  
Stainless Steel ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Welded Joints ◽  
Shot Peening ◽  
Corrosion Cracking ◽  
Glass Beads ◽  
Residual Tensile Stress ◽  
X Ray ◽  
Compressive Stresses

High residual tensile stress is an important factor contributing to stress corrosion cracking (SCC). Shot peening can impose compressive stresses on the surface of welded joints that negate the tensile stresses to enhance the SCC resistance of welded joints. In the present work, the distribution of residual stress caused by welding is measured by X-ray diffraction method. The maximum stress in the weld is close to the yield strength of AISI 304 stainless steel, and the stresses are negative at both ends of the weld and far from the weld. The X-ray method is also used to measure stress caused by shot-peening. The results show that the higher the peening coverage, the higher the residual compressive stresses in the surface of weldments. While under the same condition, the residual compressive stresses induced by glass beads shot-peening are larger than those by cast steel shots. Temperature and stress fields of welding are simulated by using ABAQUS codes. The 3-D solid elements are used in FEM. Temperature depending on material properties as well as the convection and radiation as boundary conditions are considered. The 3-D linear reduced-integration elements are used to simulate the shot peening process. The results of simulation have a good agreement with experimental data. All unpeened and peened weldments are immersed in boiling 42% magnesium chloride solution during SCC test. Unpeened specimens crack after immersion for 6 hours. The steel-peened specimens with 50% coverage crack after 310 hours, while the steel-peened specimens with 100% coverage crack for 3500 hours. However, steel-peened specimens with 200% coverage and glass-peened specimens with 50%, 100% and 200% coverage are tested for a total of 3500 hours without visible stress corrosion cracks in the peened surfaces. The experiment results indicate that shot peening is an effective method for protecting weldments against SCC and weldments peened by glass beads resist SCC better than those peened by steel shots.

AMBRONZE 413

Alloy Digest ◽  
1969 ◽  
Vol 18 (6) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Surface Treatment ◽  
Stress Corrosion ◽  
Tensile Properties ◽  
Stress Corrosion Cracking ◽  
Electrical Contact ◽  
Heat Treating ◽  
Corrosion Cracking ◽  
Tin Bronze

Abstract AMBRONZE 413 is a copper-tin bronze recommended for plater's plates and electrical contact springs. It is relatively immune to stress-corrosion cracking. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Cu-201. Producer or source: Anaconda American Brass Company.

NICROFER 5716 HMoW

Alloy Digest ◽  
1985 ◽  
Vol 34 (11) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Stress Corrosion ◽  
Tensile Properties ◽  
Stress Corrosion Cracking ◽  
Crevice Corrosion ◽  
Corrosion Cracking ◽  
Low Carbon ◽  
Nickel Chromium ◽  
Corrosion Pitting

Abstract NICROFER 5716 HMoW is a nickel-chromium-molybdenum alloy with tungsten and extremely low carbon and silicon contents. It has excellent resistance to crevice corrosion, pitting and stress-corrosion cracking. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, machining, and joining. Filing Code: Ni-324. Producer or source: Vereingte Deutsche Metallwerke AG.

NAS 825

Alloy Digest ◽  
2012 ◽  
Vol 61 (2) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Stress Corrosion ◽  
Tensile Properties ◽  
Nickel Alloy ◽  
Stress Corrosion Cracking ◽  
Chloride Ion ◽  
Heat Treating ◽  
Corrosion Cracking ◽  
Corrosion Resistant

Abstract NAS 825 is a corrosion-resistant nickel alloy that has resistance to both oxidizing and reducing environments, and with 42% nickel, the alloy is very resistant to chloride-ion stress-corrosion cracking. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-694. Producer or source: Nippon Yakin Kogyo Company Ltd.

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