New Weld Joint Strength Reduction Factors in the Creep Regime in ASME B31.3 Piping

2005 ◽  
Vol 128 (1) ◽  
pp. 46-48 ◽  
Author(s):  
Charles Becht
Keyword(s):  
Weld Joint ◽  
Joint Strength ◽  
Strength Reduction ◽  
Allowable Stresses ◽  
Process Piping ◽  
Sustained Loads ◽  
Creep Regime ◽  
Reduction Factors

The 2004 edition of ASME B31.3, Process Piping Code, includes strength-reduction factors that apply to welds operating in the creep regime for the material. These factors apply to allowable stresses for sustained loads, such as weight and pressure. This paper describes the background for the rules.

New Weld Joint Strength Reduction Factors in the Creep Regime in ASME B31.3 Piping

2005 ◽  
Author(s):  
Charles Becht
Keyword(s):  
Weld Joint ◽  
Joint Strength ◽  
Strength Reduction ◽  
Allowable Stresses ◽  
Process Piping ◽  
Sustained Loads ◽  
Creep Regime ◽  
Reduction Factors

The 2004 edition of ASME B31.3, Process Piping, includes strength reduction factors that apply to welds operating in the creep regime for the material. These factors apply to allowable stresses for sustained loads such as weight and pressure. This paper describes the background for the rules.

Fatigue-Strength-Reduction Factors for Welds in Pressure Vessels and Piping

2000 ◽  
Vol 122 (3) ◽  
pp. 297-304 ◽  
Author(s):  
Carl E. Jaske
Keyword(s):  
Fatigue Strength ◽  
Weld Joint ◽  
Pressure Vessels ◽  
Strength Reduction ◽  
Current Status ◽  
Published Data ◽  
Weld Joints ◽  
Class 1 ◽  
Asme Code ◽  
Reduction Factors

Fatigue-strength-reduction factors (FSRFs) are used in the design of pressure vessels and piping subjected to cyclic loading. This paper reviews the background and basis of FSRFs that are used in the ASME Boiler and Pressure Vessel Code, focusing on weld joints in Class 1 nuclear pressure vessels and piping. The ASME Code definition of FSRF is presented. Use of the stress concentration factor (SCF) and stress indices are discussed. The types of welds used in ASME Code construction are reviewed. The effects of joint configuration, welding process, cyclic plasticity, dissimilar metal joints, residual stress, post-weld heat treatment, the nondestructive inspection performed, and metallurgical factors are discussed. The current status of weld FSRFs, including their development and application, are presented. Typical fatigue data for weldments are presented and compared with the ASME Code fatigue curves and used to illustrate the development of FSRF values from experimental information. Finally, a generic procedure for determining FSRFs is proposed and future work is recommended. The five objectives of this study were as follows: 1) to clarify the current procedures for determining values of fatigue-strength-reduction factors (FSRFs); 2) to collect relevant published data on weld-joint FSRFs; 3) to interpret existing data on weld-joint FSRFs; 4) to facilitate the development of a future database of FSRFs for weld joints; and 5) to facilitate the development of a standard procedure for determining the values of FSRFs for weld joints. The main focus is on weld joints in Class 1 nuclear pressure vessels and piping. [S0094-9930(00)02703-7]

Computer Based Process Piping Stress Analysis: ASME B31.3 Appendix S — Example S2

2006 ◽  
Author(s):  
Don R. Edwards
Keyword(s):  
Stress Analysis ◽  
Operating Temperature ◽  
Stress Range ◽  
Explicit Equation ◽  
The Past ◽  
Process Piping ◽  
Piping Systems ◽  
Sustained Loads ◽  
Computer Based ◽  
Temperature And Pressure

The American Standards Association (ASA) B31.3-1959 Petroleum Refinery Piping Code [1] grew out of an ASA document that addressed all manner of fluid conveying piping systems. ASA B31.3 was created long before widespread engineering use of computer “mainframes” or even before the inception of piping stress analysis software. Also as B31.3 continued to pass thru standards organizations from ASA, ANSI, to ASME, the B31.3 Process Piping Code [2] (hereafter referred to as the “Code”) has remained ambiguous over the past few decades in several areas. The displacement stress range, SE, has always been explicitly defined by both verbiage and equation. Yet, the sustained condition(s) stress, SL, is mentioned not with an explicit equation but with a statement that the sustained stress shall be limited by the allowable stress at the corresponding operating temperature, Sh. Also one might infer from the vague verbiage in the Code that there is only one sustained condition; this would also be an incorrect inference. Also, assumptions would then have to be made as to which supports are allowed to be included in a sustained analysis based on whether the piping “lifts-off” any of the pipe supports during the corresponding operating condition. This paper describes the subtle yet possibly radical concepts that are included in the (recently approved for inclusion into) ASME B31.3-2006 Appendix S Example S2. This paper discusses: • when and in what manner the most severe set of operating temperature and pressure is to be used; • the concept of “sustained condition” and multiple “anticipated” sustained conditions; • determining the support scenario(s) for each anticipated sustained condition; • establishing the most severe sustained condition to evaluate and determine the stress due to sustained loads, SL; • utilizing an equation with sustained stress indices to evaluate SL; • establishing the least severe sustained condition and its effect in determining the largest displacement stress range, SE.

Process analysis and regression modelling of resistance spot welded joints of austenitic stainless steel 304L and low carbon steel sheets by using surface response methodology

2020 ◽  
pp. 095440892094088
Author(s):  
Lokesh Boriwal ◽  
RM Sarviya ◽  
MM Mahapatra
Keyword(s):  
Mathematical Model ◽  
Process Parameters ◽  
Weld Joint ◽  
Welded Joints ◽  
Joint Strength ◽  
Process Analysis ◽  
Dissimilar Material ◽  
Joint Analysis ◽  
Low Carbon ◽  
Spot Welded

Evaluating the strength performance of spot-welded joints of dissimilar material is critical for their continued integration into the automobile and aerospace industries. The effect of weld joint strength is an important consideration in the design of weld structures. The objective of the present work undertaken to investigate the effect of the input process parameters on the strength of the welded joint of dissimilar material. Full factorial design (FFD) has used for designing the experiment matrix. Further, experimental results have used to develop a mathematical model to predict the strength of the spot weld joint. Analysis of Variance (ANOVA) has been applied to establish the correlation between the process parameters and their interaction on the output. The confirmation test case experiments have conducted for validating the developed mathematical model and observed that the developed model is capable of evaluating weld joint strength within the process parameters.

Cross-Weld Creep Comparison of Power Plant Steels CrMoV, P91 and P92

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
David W. J. Tanner ◽  
Wei Sun ◽  
Thomas H. Hyde
Keyword(s):  
Heat Affected Zone ◽  
Failure Time ◽  
Parent Material ◽  
Strength Reduction ◽  
Weld Strength ◽  
Creep Tests ◽  
Type Iv ◽  
Different Temperatures ◽  
Using Data ◽  
Reduction Factors

Results obtained from high temperature creep tests of ferritic steel CrMoV, P91 and P92 cross-weld specimens are compared. Data are presented normalized with the results of the corresponding parent metals in order to compare the materials tested at different temperatures and stresses, and to identify characteristic cross-weld material trends. All cross-weld failures occurred in the heat-affected zone (HAZ) adjacent to the parent metal, known as type IV, at earlier test durations than for the parent material specimens. The relative performance of the cross-welds was found to decrease with decreasing stress. The CrMoV cross-weld specimens showed by far the lowest weld strength reduction factors and greatest notch strengthening, determined by testing uniaxially loaded bars with semicircular circumferential notches located in the heat-affected zone. The P91 and P92 cross-weld specimens were found to have similar (high) weld strength reduction factors and showed little or no notch strengthening. The failure time of a P92 cross-weld specimen relative to the P92 parent material could be estimated using data from P91 cross-weld and relative parent material tests.

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