Creep Behavior of a Bimetallic Welded Joint in a Nuclear Piping System

2003 ◽  
Author(s):  
Y. P. Yang ◽  
F. W. Brust ◽  
J. Oh
Keyword(s):  
Residual Stress ◽  
Creep Behavior ◽  
Welded Joint ◽  
Creep Damage ◽  
Steel Pipe ◽  
304 Stainless Steel ◽  
Creep Model ◽  
Piping System ◽  
Damage Development ◽  
Modeling Tools

The information of the creep behavior of a thick welded joint is very important to secure the safety of high temperature service devices. The creep damage development and behavior are very complex; hence it is time consuming to practice the experiment and theoretical analyses. In this paper a simple accurate model was developed to analyze the creep behavior of weld metal and heat-affected zone on a thick bimetallic welded pipe. The pipe was made by welding an A508-class-2 carbon steel pipe to a 304 stainless steel pipe with a shielded metal arcwelding process using INCONEL 182 electrodes. Virtual fabrication technology weld modeling tools (VFT™) developed jointly by Battelle and Caterpillar was used to obtain welding-induced residual stress. The weld residual stress was read into the creep model as initial stress condition for creep analysis. A temperature 1000°F was applied on the bimetallic weld model with inside pressure and axial loading. The simulation results indicated that creep strains were not uniform through the weld joint due to weld residual stresses, materials creep behavior and geometry changes. Some stress and strain concentrations were found on the A508 steel near buttering region, which results in axial cracks.

An Experimental Study on the Effect of Prior Plastic Straining on Creep Behavior of 304 Stainless Steel

1993 ◽  
Vol 115 (2) ◽  
pp. 200-203 ◽  
Author(s):  
Z. Xia ◽  
F. Ellyin
Keyword(s):  
Stainless Steel ◽  
Plastic Strain ◽  
Strain Rate ◽  
Creep Behavior ◽  
Test Procedure ◽  
Constant Strain Rate ◽  
304 Stainless Steel ◽  
Creep Model ◽  
Plastic Strain Rate ◽  
Creep Tests

Constant strain-rate plastic straining followed by creep tests were conducted to investigate the effect of prior plastic straining on the subsequent creep behavior of 304 stainless steel at room temperature. The effects of plastic strain and plastic strain-rate were delineated by a specially designed test procedure, and it is found that both factors have a strong influence on the subsequent creep deformation. A creep model combining the two factors is then developed. The predictions of the model are in good agreement with the test results.

scholarly journals Experimental and Theoretical Studies on the Creep Behavior of Bayer Red Mud

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Baoyun Zhao ◽  
Wei Huang ◽  
Zhile Shu ◽  
Mengmeng Han ◽  
Yanbo Feng
Keyword(s):  
Creep Strain ◽  
Creep Behavior ◽  
Red Mud ◽  
Damage Model ◽  
Creep Damage ◽  
Creep Model ◽  
Creep Tests ◽  
Accelerated Creep ◽  
Bayer Red Mud ◽  
Creep Damage Model

Long-term stability and safety of the Bayer red mud (BRM) disposal field is very important for the local residents’ life, which necessitates the knowledge of its creep behavior. In order to investigate the creep behavior of BRM, a series of triaxial drained creep tests were conducted by using an improved triaxial creep apparatus. The results indicate that the creep behavior of BRM is significant with confining and deviatoric stresses being critical factors. The creep strain is in a nonlinear relationship with stress and time, and a larger deviator stress will lead to a larger creep strain. The main failure mechanism of BRM is plastic shear, accompanied by a significant compression and ductile dilatancy. Based on the test results, two well-established creep models, the Burgers creep model and Singh–Mitchell creep model, were used to comparatively analyze the creep behavior of the Bayer red mud under a certain stress level. Then, an improved Burgers creep damage constitutive model with the addition of a damage variable was proposed, whose parameters were also analyzed in detail. The comparison of the calculated values of the creep model and the experimental values shows that the proposed creep damage model can better describe the instant elastic deformation, attenuation creep, steady-state creep, and accelerated creep stages of the Bayer red mud.

scholarly journals Evaluation of Residual Stress Distribution in Austenitic Stainless Steel Pipe Butt-Welded Joint

2009 ◽  
Vol 27 (2) ◽  
pp. 240s-244s ◽  
Author(s):  
Akira MAEKAWA ◽  
Michiyasu NODA ◽  
Shigeru TAKAHASHI ◽  
Toru OUMAYA ◽  
Hisashi SERIZAWA ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Stress Distribution ◽  
Welded Joint ◽  
Residual Stress Distribution ◽  
Steel Pipe ◽  
Stainless Steel Pipe

A Remaining Life Assessment of Autofrettaged Tubes From an LDPE Facility

2014 ◽  
Author(s):  
Jeffrey D. Cochran ◽  
Charles H. Panzarella
Keyword(s):  
Residual Stress ◽  
Stress Relaxation ◽  
Brittle Fracture ◽  
Creep Damage ◽  
Limit Load ◽  
Life Assessment ◽  
Creep Model ◽  
Normal Operation ◽  
Remaining Life ◽  
Remaining Life Assessment

The manufacture of low density polyethylene by radical polymerization regularly subjects components to extreme pressures exceeding 20 ksi and, possibly, to runaway reactions with fluid temperatures exceeding 2000 °F and pressures above 30 ksi. Components are often treated with autofrettage to induce a beneficial residual stress distribution that retards crack growth and increases fatigue life. This paper presents a case-study remaining life assessment of two autofrettaged tubes in accordance with API 579-1/ASME FFS-1. Measurements of the remaining residual stress after 40+ years in service agree with FEA predictions of the initial residual stress, indicating no significant stress relaxation over this time. Nevertheless, the MPC Omega creep model is calibrated to the tube material and used to estimate the potential for stress-relaxation due to creep. The model correctly predicts no stress relaxation for over 40 years of normal operation, but creep damage and stress relaxation are predicted for temperature excursions as low as 900 °F for 10.8 s. ASME FFS-1 procedures for assessing brittle fracture, fatigue, plastic collapse, and creep damage are then adapted for autofrettaged components. It is found that autofrettage increases resistance to brittle fracture and fatigue, does not affect limit load analyses, and alters creep damage distributions.

scholarly journals Residual Stress Distribution in Carbon Steel Pipe Welded Joint Measured by Neutron Diffraction

2000 ◽  
Vol 49 (12Appendix) ◽  
pp. 287-294 ◽  
Author(s):  
Makoto HAYASHI ◽  
Masayuki ISHIWATA ◽  
Yukio MORII ◽  
Nobuaki MINAKAWA ◽  
John H. ROOT
Keyword(s):  
Residual Stress ◽  
Carbon Steel ◽  
Stress Distribution ◽  
Neutron Diffraction ◽  
Welded Joint ◽  
Residual Stress Distribution ◽  
Steel Pipe

Investigations on Creep Behavior of P91-Type Steel Using Combined Creep Damage Model

2013 ◽  
Author(s):  
Fujun Liu ◽  
Ping Tang ◽  
Shuai Kong ◽  
Zhangwei Ling ◽  
Muling Zheng ◽  
...  
Keyword(s):  
Constitutive Model ◽  
Creep Behavior ◽  
Power Plants ◽  
Damage Model ◽  
Creep Damage ◽  
Damage Function ◽  
Creep Model ◽  
Secondary Creep ◽  
Type Steel ◽  
Damage Theory

P91-type steel is widely used for the high-temperature pipe work components in advanced power plants. The creep behavior of the P91-type steel has been studied by many researchers during the past years. Since it is well known that the creep behavior of P91-type steel cannot be satisfactorily described by a simple, Arrhenius-type, power-law constitutive model. While Norton-Bailey creep is a deviatoric temperature-dependent creep model, furbished with a time-hardening creep model, which is the most common model for modeling primary and secondary creep together, and Kachanov-Rabotnov creep damage theory described with Norton creep model can be used to model tertiary creep. Both of them based on Norton creep constitutive equation. In this paper, based on the Norton-Bailey creep law and Kachanov-Rabotnov creep damage theory, a new combined constitutive model has been developed, in which the creep and damage function are both considered as nonlinear variables. The damage parameters in the model have clear physical meaning and can be determined from the benchmark experiment. The results indicated that this combined damage model was applicable to describe the full damage evolution for P91-type steel.

Numerical simulation of creep damage for low alloy steel welded joint considering as-welding residual stress

2012 ◽  
Vol 242 ◽  
pp. 26-33 ◽  
Author(s):  
Guodong Zhang ◽  
Changyu Zhou ◽  
Zhaoxi Wang ◽  
Fei Xue ◽  
Yanfen Zhao ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Alloy Steel ◽  
Welded Joint ◽  
Creep Damage ◽  
Welding Residual Stress ◽  
Low Alloy Steel
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