Contact Yield Initiation and Its Influence on Rolling Contact Fatigue of Case-Hardened Steels

Abstract Stress distributions and plastic deformation zones are factors directly influencing the fatigue life of components under cyclic contact. An effective approach to improving the resistance of a steel to contact fatigue failure is surface hardening, which builds gradient yield strength from the surface of the steel to the bulk. When using the distortion energy theory as the criterion to identify failure initiation for a case-hardened steel, contact yield starts in the subsurface wherever the von Mises stress reaches the local material strength, rather than at the point of the maximum von Mises stress in the subsurface. If the yield strength changes from the surface to the bulk following a straight line, the location of yield initiation should occur at the tangency of the strength line and the von Mises stress curve. Analyses on circular, rectangular, and elliptical contacts are presented to reveal the locations of contact yield initiation for such case-hardened steels subjected to rolling contact stresses, for which the influence of friction can be ignored. A group of formulas relating contact yield initiation, in terms of the critical pressure, location of the first yield, and plasticity index (transition to plasticity) to case-hardening parameters, such as the case slope, the minimum case depth, and surface and bulk strengths, are derived to facilitate contact element designs using case-hardened materials. The results are applied to examine the rolling contact behaviors of several case-hardened steels, and the data correlation suggests that their rolling contact fatigue lives are related to a nondimensional case-hardening slope besides external loading.

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Determination of optimal residual stress profiles for improved rolling contact fatigue resistance

MATEC Web of Conferences ◽

10.1051/matecconf/201930006002 ◽

2019 ◽

Vol 300 ◽

pp. 06002

Author(s):

Hamidreza Mahdavi ◽

Konstantinos Poulios ◽

Christian F. Niordson

Keyword(s):

Rolling Contact Fatigue ◽

Contact Fatigue ◽

Rolling Contact ◽

Von Mises Stress ◽

Far Field ◽

Damage Initiation ◽

Micro Scale ◽

Different Depths ◽

Stress Profiles ◽

Von Mises

A theoretical framework is developed for the evaluation of favorable residual stress profiles, suppressing fatigue damage initiation in rolling contact fatigue. Non-metallic inclusions at the microstructure of bearings are one of the most important reasons for fatigue damage initiation since they act as stress risers. In order to evaluate the stress state around such inclusions at the micro-scale, macroscopic stress histories are determined by Hertzian contact theory at different depths below the raceway for a typical roller bearing. These stress distributions are then used as far-field stresses for a micro-scale model accounting for single inclusions of different geometries and orientations. Eshelby’s method is used to relate far-field and local stresses in the vicinity of inclusions. The von Mises stress criterion is then used as a conservative estimator of crack initiation due to micro-scale plasticity. The effect of compressive residual stresses added to the axial and circumferential normal stress components at different depths is analyzed. The von Mises stress field around different inclusions at different depths is investigated in order to determine the most critical case in terms of micro-scale plastic deformation. Finally, an optimization process is carried out in order to determine the residual stresses that minimize the maximum observed von Mises stress as a function of depth.

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Improvement of Rolling Contact Fatigue Life by a Preliminary Loading in Elastic-Plastic Domain

Volume 4: Fatigue and Fracture; Fluids Engineering; Heat Transfer; Mechatronics; Micro and Nano Technology; Optical Engineering; Robotics; Systems Engineering; Industrial Applications ◽

10.1115/esda2008-59137 ◽

2008 ◽

Author(s):

Spiridon Cretu

Keyword(s):

Fatigue Life ◽

Residual Stresses ◽

Rolling Contact Fatigue ◽

Contact Fatigue ◽

Rolling Contact ◽

Ball Bearings ◽

Loading Cycle ◽

Elastic Plastic ◽

Plastic Domain ◽

Von Mises

An analysis model has been developed to model the nonlinear strain rate dependent deformation of rolling bearing steel stressed in the elastic-plastic domain. The model is developed in the frame of the incremental theory of plasticity by using the von Mises yield criterion and Prandtl-Reuss equations. By considering the isotropic and non-linear kinematic hardening laws of Lemaitre-Caboche, the model accounts for the cyclic hardening phenomena. To attain the final load of each loading cycle, the two bodies are brought into contact incrementally. For each new load increment new increments for the components of stress and strain tensors, but also increments of residual stresses, are computed for each point of the 3D mesh. Both, the new contact geometry and residual stresses distributions, are further considered as initial values for the next loading cycle, the incremental technique being reiterated. The cyclic evaluation process of both, plastic strains and residual stresses is performed until the material shakedowns. The experimental part of the paper regards to the rolling contact fatigue tests carried out on two groups of line contact test specimens and on two groups of deep groove ball bearings. In both cases, the experimental data reveal more than two times greater fatigue life for the group with induced residual stresses versus the life of the reference group. The von Mises equivalent stress is considered in Ioannides-Harris rolling contact fatigue model to obtain theoretical lives. The theoretical analysis revealed greater fatigue lives for the test specimens and for the ball bearings groups with induced residual stresses than the fatigue lives of the corresponding reference groups.

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Rolling contact fatigue behavior of sintered and hardened steels

Practical Failure Analysis ◽

10.1007/bf02715457 ◽

2002 ◽

Vol 2 (4) ◽

pp. 71-75 ◽

Cited By ~ 4

Author(s):

R. Gnanamoorthy ◽

N. Rajiv ◽

K. Gopinath ◽

Y. Miyahsita ◽

Y. Mutoh

Keyword(s):

Fatigue Behavior ◽

Rolling Contact Fatigue ◽

Contact Fatigue ◽

Rolling Contact ◽

Hardened Steels

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Evaluation of Rolling Contact Fatigue of a Carburized Wind Turbine Gear Considering the Residual Stress and Hardness Gradient

Journal of Tribology ◽

10.1115/1.4040052 ◽

2018 ◽

Vol 140 (6) ◽

Cited By ~ 12

Author(s):

Wei Wang ◽

Huaiju Liu ◽

Caichao Zhu ◽

Philippe Bocher ◽

Heli Liu ◽

...

Keyword(s):

Residual Stress ◽

Stress Distribution ◽

Rolling Contact Fatigue ◽

Contact Fatigue ◽

Residual Stress Distribution ◽

Rolling Contact ◽

Material Strength ◽

Initial Residual Stress ◽

Failure Risk ◽

Local Material

Carburized gears are applied extensively in large-scale heavy duty machines such as wind turbines. The carburizing and quenching processes not only introduce variations of hardness from the case to the core but also generate a residual stress distribution, both of which affect the rolling contact fatigue (RCF) during repeated gear meshing. The influence of residual stress distribution on the RCF risk of a carburized wind turbine gear is investigated in the present work. The concept of RCF failure risk is defined by combining the local material strength and the multi-axial stress condition resulting from the contact. The Dang Van multi-axial fatigue criterion is applied. The applied stress field is calculated through an elastic-plastic contact finite element model. Residual stress distribution and the hardness profile are measured and compared with existed empirical formula. Based upon the Pavlina–Tyne relationship between the hardness and the yield strength, the gradient of the local material strength is considered in the calculation of the RCF failure risk. Effects of the initial residual stress peak value and its corresponding depth position are studied. Numerical results reveal that compressive residual stress (CRS) is beneficial to RCF fatigue life while tensile residual stress (TRS) increases the RCF failure risk. Under heavy load conditions where plasticity occurs, the accumulation of the plastic strain within the substrate is significantly affected by the initial residual stress distribution.

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Electrodeposited and Hardened Iron for Rolling Contact Fatigue Applications

Journal of Lubrication Technology ◽

10.1115/1.3451471 ◽

1970 ◽

Vol 92 (4) ◽

pp. 557-564 ◽

Cited By ~ 2

Author(s):

R. K. Kepple ◽

E. R. Mantel ◽

O. J. Klingenmaier ◽

R. L. Mattson

Keyword(s):

Rolling Contact Fatigue ◽

Contact Fatigue ◽

Base Material ◽

Rolling Contact ◽

Rolling Element Bearing ◽

Fatigue Properties ◽

Case Hardening ◽

Deposit Thickness ◽

Fatigue Development ◽

Bearing Materials

A new approach to the material cleanliness problem in rolling contact fatigue involving the use of hardened electrolytically deposited iron (or iron-nickel alloy) is discussed. It was demonstrated that the fatigue strength of surfaces prepared by case hardening electrodeposited iron or iron–4 percent nickel can be equivalent to the best of commercial rolling element bearing materials. Three base materials to which the plated material was applied were investigated. These covered a broad range of quality. The associated deposit thickness problem was investigated. Excellent fatigue properties were obtained if the deposit thickness was great enough to avoid fatigue development in the base material. With deposit thicknesses less than this amount, some improvement in fatigue life was obtained over that of the unplated base material.

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Analysis of Residual Stresses Impact on Fatigue Life of Rolling Contacts

ASME/STLE 2007 International Joint Tribology Conference, Parts A and B ◽

10.1115/ijtc2007-44399 ◽

2007 ◽

Author(s):

S. Cretu ◽

M. Benchea

Keyword(s):

Fatigue Life ◽

Residual Stresses ◽

Reference Group ◽

Yield Criterion ◽

Rolling Contact Fatigue ◽

Equivalent Stress ◽

Contact Fatigue ◽

Rolling Contact ◽

Deformation Analysis ◽

Von Mises

The values of residual stresses resulting from a heavily stressed contact are numerically evaluated by employing a three-dimensional strain deformation analysis model. The model is developed in the frame of the incremental theory of plasticity including the von Mises yield criterion, Prandtl-Reuss equations, and Ramberg-Osgood stress-strain equation. Two groups of cylindrical specimens were subjected to rolling contact fatigue, one as the reference group and the other with an induced residual stresses state. To obtain theoretical lives of the tested groups the von Mises equivalent stress is used in Ioannides-Harris rolling contact fatigue model. Both, the experimental data and theoretical analysis reveal more than two times greater fatigue life for the group with induced residual stresses versus the life of the reference group.

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Research on the rolling contact fatigue life of the bearing considering the friction effect

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406220951214 ◽

2020 ◽

pp. 095440622095121

Author(s):

Yimin Zhang ◽

Yongzhen Liu

Keyword(s):

Friction Coefficient ◽

Rolling Contact Fatigue ◽

Contact Fatigue ◽

Rolling Contact ◽

Von Mises Stress ◽

Surface Shear Stress ◽

Angular Contact Ball Bearing ◽

Maximum Peak ◽

Friction Effect ◽

Peak Value

In this paper, a theoretical model is proposed to analyze the friction effect on the rolling contact fatigue (RCF) life of the angular contact ball bearing (ACBB). Firstly, the quasi-static model without race control hypothesis is introduced to study the load characteristics of the ACBB under different loading conditions. Then, the friction coefficient is quantitatively calculated by analyzing the relation between the gyroscopic torque and the sphere-race contact load. The effects of the axial load, radial load, torque load and rotating speeds on the friction coefficient, the maximum value of the sub-surface von Mises stress (SSVS) and the maximum peak-peak value of the sub-surface shear stress (SSSS) are subsequently investigated. The results show that they can significantly affect the friction coefficient and further influence the stress field beneath the contact surface. Further studies illustrate that the friction coefficient cannot affect the maximum peak-peak value of the SSSS but can change the distribution of the SSVS field. The relative RCF life of the sphere-race contact is calculated and the published studies confirm the accuracy of the calculation.

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