An Examination of the Influence of Residual Stresses on the Fatigue and Fracture of Railroad Rail

2009 ◽  
pp. 132-132-26 ◽  
Author(s):  
RC Rice ◽  
BN Leis ◽  
ME Tuttle
Keyword(s):  
Residual Stresses ◽  
Railroad Rail ◽  
Fatigue And Fracture

scholarly journals Experimental Consideration of Conditions for Measuring Residual Stresses of Rails Using Magnetic Barkhausen Noise Method

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5374
Author(s):  
Young-In Hwang ◽  
Yong-Il Kim ◽  
Dae-Cheol Seo ◽  
Mu-Kyung Seo ◽  
Woo-Sang Lee ◽  
...  
Keyword(s):  
Residual Stresses ◽  
High Speed ◽  
Barkhausen Noise ◽  
Noise Band ◽  
Magnetic Barkhausen Noise ◽  
Continuous Increase ◽  
Fracture Characteristics ◽  
Fatigue And Fracture ◽  
The Difference ◽  
Number Of Passes

Residual stress, a factor affecting the fatigue and fracture characteristics of rails, is formed during the processes of fabrication and heat treatment, and is also generated by vertical loads on wheels due to the weight of vehicles. Moreover, damage to rails tends to accelerate due to the continuous increase in the number of passes and to the high speed of passing vehicles. Because this can have a direct effect on safety accidents, having a technique to evaluate and analyze the residual stresses in rails accurately is very important. In this study, stresses due to tensile loads applied to new rails and residual stresses remaining in used rails were measured by using magnetic Barkhausen noise method. First, a magnetization frequency and noise band suitable for the rails were selected. Moreover, by applying tensile loads to specimens and comparing the difference in magnetization amplitudes for each load, the stresses applied to the rails by using the magnetic Barkhausen noise method were measured, and the analysis of the results was verified. Based on these results, the difference in the results for the loads asymmetrically applied according to the wheel shape was analyzed by measuring for the head parts of used rails.

The Effect of Residual Stresses on the Fracture Resistance of Ductile Steels

2002 ◽  
Author(s):  
Noel P. O’Dowd ◽  
Yuebao Lei
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Residual Stresses ◽  
Crack Opening ◽  
Stress Distributions ◽  
Residual Stress Field ◽  
Element Analysis ◽  
Fatigue And Fracture ◽  
Negative Effect ◽  
Fracture Performance

Tensile residual stresses, such as those generated by welding, act as crack opening stresses and can have a negative effect on the fatigue and fracture performance of a component. In this work the effect of representative residual stress distributions on the fracture behaviour of a ferritic steel has been examined using finite element analysis. A Gurson-type void growth model is used to model the effect of ductile tearing ahead of a crack. For the cases examined it is seen that a tensile residual stress field may lead to a reduction in the toughness of the material (as represented by the J-resistance curve). The observed difference in toughness can be linked to the different constraint levels in the specimens due to the introduction of the residual stress field and can be rationalised through the use of a two parameter, J–Q approach.

Decarburization

Carburizing ◽  
1999 ◽  
pp. 37-49
Keyword(s):  
Residual Stresses ◽  
Physical Metallurgy ◽  
Corrective Measures ◽  
Fracture Behaviors ◽  
Fatigue And Fracture ◽  
Characteristic Features

Abstract This chapter explains how decarburization can occur during carburizing processes and how to limit the severity of its effects. It describes the reactions and conditions that result in a loss of carbon atoms and how they vary with changes in the physical metallurgy of the affected material and the processing environment. It examines the characteristic features of decarburized microstructures and assesses their influence on hardness, residual stresses, and fatigue and fracture behaviors. It also discusses corrective measures and practical considerations regarding their use.

scholarly journals Development of Residual Stress Simulation and Experimental Measurement Tools for Stainless Steel Pressure Vessels

2015 ◽  
Author(s):  
Thomas B. Reynolds ◽  
Arthur A. Brown ◽  
Lauren L. Beghini ◽  
Timothy D. Kostka ◽  
Chris W. San Marchi
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Residual Stresses ◽  
Pressure Vessels ◽  
Contour Method ◽  
Residual Stress State ◽  
Measurement Tools ◽  
Fatigue And Fracture ◽  
Evolution Of Microstructure ◽  
Stress Simulation

In forged, welded, and machined components, residual stresses can form during the fabrication process. These residual stresses can significantly alter the fatigue and fracture properties compared to an equivalent component containing no residual stress. When performing lifetime assessment, the residual stress state must be incorporated into the analysis to most accurately reflect the initial condition of the component. The focus of this work is to present the computational and experimental tools that we are developing to predict and measure the residual stresses in stainless steel for use in pressure vessels. The contour method was used to measure the residual stress in stainless steel forgings. These results are compared to the residual stresses predicted using coupled thermo-mechanical simulations that track the evolution of microstructure, strength and residual stress during processing.

Residual Stress Effects and Predicting Crack Growth in Weldments

2016 ◽  
Vol 258 ◽  
pp. 432-435
Author(s):  
Petr Brož
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Crack Growth ◽  
Numerical Models ◽  
Limit Load ◽  
Stress Effects ◽  
R Ratio ◽  
Fatigue And Fracture ◽  
Stress Zone ◽  
Fracture Assessment

It is explained which way a welded zone integrity has to concentrate on a number of inconveniences resulting from the weld behaviour. These problems will be discussed for evaluation of fatigue and fracture. Going after the fracture assessment address, the effect of weld configuration on stress intensity factor is fixing. A pertinent input to these methods is the limit load. In the view of the prominence of residual stresses in weldments, the interpretation of combined primary and secondary stresses in fracture evaluation is most desirable to be described in great detail. The influence of residual stresses on R – ratio is given. The weldment testing methods involve the techniques for definite microstructural regions and elimination of residual stress effects on fracture toughness measuring. For FCG rate predicting, the initial residual stresses are put into numerical models and residual stress distribution is simulated, incorporating crack growth. The technique is suggested for cracks initiating within a weld, namely in tensile residual stress zone.

Carbides

Carburizing ◽  
1999 ◽  
pp. 51-75
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Residual Stresses ◽  
Alloying Elements ◽  
Processing Conditions ◽  
Carbide Phases ◽  
Composition And Structure ◽  
Fracture Behaviors ◽  
Fatigue And Fracture ◽  
Carburizing Process

Abstract This chapter discusses the formation of free carbides and their effect on case-carburized components. It explains how alloying elements influence the composition and structure of carbide phases produced at cooling rates typical of carburizing process. It describes the morphology and distribution of the various types of carbides formed and explains how they affect mechanical properties such as hardness, residual stresses, fatigue and fracture behaviors, and wear resistance. It also provides guidance for determining what processing conditions to avoid and when and why parts should be rejected.

Residual Stresses Evaluation in Welds and Implications for Design for Pressure Vessel Applications

2005 ◽  
Author(s):  
John W. H. Price ◽  
Anna Paradowska ◽  
Trevor Finlayson
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Residual Stresses ◽  
Scale Up ◽  
Small Scale ◽  
Fitness For Purpose ◽  
Fatigue And Fracture ◽  
Single Bead ◽  
Key Issues ◽  
Neutron Diffraction Technique

Welding residual stresses have important consequences on the performance of engineering components. High residual stresses lead to loss of performance in corrosion, fatigue and fracture but as yet these consequences are poorly quantified. The major cause of this is that residual stress often remains the single largest unknown in industrial damage situations since they are difficult to measure or estimate theoretically. One of the key issues in the study of residual stress is that the detail of the stress distribution on a small scale (in the order of millimetres) can be important. In this paper, the neutron diffraction technique is used which while it is a very expensive technique, is capable of non-destructively measuring residual stresses at this scale up to a depth of 35mm. The investigation reported compares the residual stress characteristics due to various restraints for a single bead and in fully restrained samples with different numbers of beads. The findings have important consequences with respect to design of welding procedures and fitness for purpose assessments.

Surface Hardening

2015 ◽  
pp. 499-549
Keyword(s):  
Residual Stresses ◽  
Induction Heating ◽  
Surface Hardening ◽  
Contact Fatigue ◽  
Surface Oxidation ◽  
Surface Treatments ◽  
Bending Fatigue ◽  
Fatigue And Fracture ◽  
Flame Hardening ◽  
Mechanical Components

Mechanical components often require surface treatments to meet application demands. This chapter describes several surface hardening treatments for steel and their effect on microstructure, composition, and properties. It discusses flame hardening, induction heating, carburizing, nitriding, carbonitriding, and nitrocarburizing. The discussion on carburizing addresses several interrelated factors, including processing principles, alloying, surface oxidation, residual stresses, bending fatigue, contact fatigue, and fracture.

Sign in / Sign up

Export Citation Format

Share Document