Wear properties of two U71Mn K and U71Mn G rail steel welds during rolling contact fatigue

2019 ◽  
Vol 33 (01n03) ◽  
pp. 1940041
Author(s):  
Jinfang Peng ◽  
Xuhui Xie ◽  
Weijun Song ◽  
Wei Li ◽  
Zhiping Luo
Keyword(s):  
High Speed ◽  
Rail Steel ◽  
Rolling Contact Fatigue ◽  
Weld Zone ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Superior Performance ◽  
Wear Properties ◽  
Abrasion Damage ◽  
Steel Welds

Wear behaviors of two U71Mn K and U71Mn G rail steels have been systematically investigated with the simulated experiments during the tolling contact fatigue using samples taken from their base materials, the heat-affected zones near the weld, and the weld zones, respectively. The results demonstrate that there are significant differences between the nonweld and the weld zones for both steels. With higher hardness of U71Mn G over U71Mn K, the U71Mn G steel has mild abrasion damage, reduced weight loss from wear and reduced corrugations of the weld zone during the experiment with increased simulative speed; while its other features such as the plastic deformation and cracks are almost the same compared with the U71Mn K steel. The U71Mn G steel demonstrates superior performance over U71Mn K at the high-speed rolling experiment.

Dry and lubricated wear of rail steel under rolling contact fatigue - Wear mechanisms and crack growth

Wear ◽  
2017 ◽  
Vol 380-381 ◽  
pp. 240-250 ◽  
Author(s):  
Santiago Maya-Johnson ◽  
Juan Felipe Santa ◽  
Alejandro Toro
Keyword(s):  
Crack Growth ◽  
Wear Mechanisms ◽  
Rail Steel ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Fatigue Wear

Evaluation of Surface Defects of Wheel and Rail for Korean High-Speed Railway

2010 ◽  
Vol 654-656 ◽  
pp. 2499-2502 ◽  
Author(s):  
Chan Woo Lee ◽  
Seok Jin Kwon
Keyword(s):  
High Speed ◽  
Surface Defects ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Railway Vehicle ◽  
High Speed Railway ◽  
Main Research ◽  
Rail Systems ◽  
Micro Cracks

Wheels of the railway vehicle play the important role for driving train through wheel-rail interaction. Especially wheel profile is one of the most important design factors to rule the running stability and safety of train. Accordingly, the control of rolling contact fatigue-related defects is an ongoing concern for both safety and cost reasons. This process is referred to as ratcheting. Wear of wheel and rail surfaces occur due to a mixture of adhesive, abrasive and corrosive processes. In wheel/rail systems with little wear, such failure is manifested by the appearance of closely spaced micro-cracks. In the present paper, a evaluation of surface defects of wheel and rail for Korean high-speed railway. The main research application is the wheel-rail maintenance of Korea high-speed train.

A Possible Mechanism for Rail Dark Spot Defects

1998 ◽  
Vol 120 (2) ◽  
pp. 304-309 ◽  
Author(s):  
M. Kaneta ◽  
K. Matsuda ◽  
K. Murakami ◽  
H. Nishikawa
Keyword(s):  
Fracture Mechanics ◽  
Fatigue Failure ◽  
High Speed ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Traction Force ◽  
Rolling Contact ◽  
Dark Spot ◽  
A Posteriori ◽  
Direction Opposite

Rail dark spot defect, also termed squat failure or shelling, which is a kind of rolling contact fatigue failure and occurs frequently on running surfaces of railway rails carrying high speed traffic, is one of the most dangerous rail failures. The dark spot crack is characterized by a principal crack propagating in the direction of traffic and a second crack growing in the direction opposite to traffic. By using a newly developed two-disk machine, the authors have succeeded in reproducing very similar dark spot cracks to those which appear in actual rails. It is found that the dark spot defects are caused by frequent repetitions of dry and wet runnings, and that the traction force plays an important role for the occurrence of the cracks. The principal crack may occur from a tiny pit formed a posteriori on the contacting surface and after that, the second crack is formed by cracks branched from the extended principal crack. It has also been proved experimentally that water is capable of entering the tip of the crack. Furthermore, a possible mechanism for the dark spot cracking has been proposed on the basis of the fracture mechanics approach.

Theory of Lubrication and Failure of Rolling Contacts

1961 ◽  
Vol 83 (2) ◽  
pp. 213-222 ◽  
Author(s):  
B. Sternlicht ◽  
P. Lewis ◽  
P. Flynn
Keyword(s):  
Fatigue Life ◽  
Contact Zone ◽  
High Speed ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Fatigue Tests ◽  
Rolling Contact ◽  
Inlet Temperature ◽  
Fluid Properties ◽  
Contact Fatigue Life

The fatigue life of rolling-element bearings has been the subject of numerous investigations. Most recently the influence of the lubricant on fatigue failure has been given added emphasis. This paper presents the results of an investigation which was undertaken in order to gain a better understanding of fluid behavior in the contact zone and to determine the influence of the lubricant on rolling contact fatigue life. The investigation had three distinct facets: (a) An analysis was performed on pressure and temperature distribution within the contact zone of rolling disks. In the analysis Reynolds, energy, and elasticity equations were solved simultaneously and fluid properties, such as viscosity dependence on temperature and pressure were included. (b) Dynamic stresses in two contacting cylindrical bodies were measured by means of photoelastic techniques. These measurements were used to test the validity of the analytically predicted stress distribution. (c) High-speed ball-bearing fatigue tests were conducted with two specially blended oils which had the same viscosity at the bearing inlet temperature, but widely different pressure viscosity characteristics. The physical characteristics of the oils were the same as those considered in the analysis. The paper summarizes the work and presents a hypothesis for the failure mechanism.

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