Research on Contact Fatigue Properties of Some Materials Used for Heavy Load Gear

2010 ◽  
Vol 139-141 ◽  
pp. 360-363
Author(s):  
Ying Xia Yu ◽  
Bo Lin He ◽  
Er Yu Shao
Keyword(s):  
Fatigue Life ◽  
Crack Propagation ◽  
Maximum Shear Stress ◽  
Contact Fatigue ◽  
Fatigue Tests ◽  
Experimental Results ◽  
Fatigue Properties ◽  
Heavy Load ◽  
Contact Fatigue Life ◽  
Materials Used

The contact fatigue tests were carried out using three kind of steel(45, 42CrMo, 40CrNi2Mo) which were quenched and tempered to the same medium hardness(HRC37±1). The experimental equipment is JPM-1 type contact fatigue tester. During the experiment process, the contact stress is 1600MPa and the surface roughness is 0.4 um. The crack initiation and the crack propagation direction were observed by using SEM. The contact fatigue failure mechanism was also analyzed. The experimental results were analyzed by using Weibull distribution. The experimental results show that the contact fatigue crack was initiated in the roller surface. With increasing of the cycle, the initiated crack propagates into subsurface and becomes to pitting. The pitting becomes bigger and bigger and leads to failure finally. The maximum shear stress is the main driving force for the crack propagation. The contact fatigue life increases in sequence of 45, 42CrMo, 40CrNi2Mo. The contact fatigue life has the relationship with the shearing resistant stress Тk. About the same carbon content, the value of the shearing resistant stress Тk becomes greater with increasing the alloying elements. The best material used for making heavy duty gear is 40CrNi2Mo steel.

Experimental Investigations Upon Fatigue Life of Circular Contacts With Transversal Furrow

2005 ◽  
Author(s):  
Delia F. Cerlinca ◽  
Emanuel N. Diaconescu
Keyword(s):  
Fatigue Life ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Fatigue Tests ◽  
Geometric Parameters ◽  
Rolling Contact ◽  
Experimental Results ◽  
Experimental Investigations ◽  
Contact Fatigue Life

Rolling contact fatigue depends essentially on both surface and subsurface populations of defects. First, this paper describes experimental results obtained in rolling contact fatigue tests in the presence of a furrow oriented transversally to the race-way. Then an attempt to predict theoretically the effect of geometric parameters of the furrow upon contact fatigue life is described.

Effect of Lubricant Viscosity on Gearing Contact Fatigue Life

2012 ◽  
Vol 190-191 ◽  
pp. 1295-1301 ◽  
Author(s):  
Xiu Mei Qi ◽  
Chuang Kuan Gao ◽  
Zeng Qiang Zhang
Keyword(s):  
Fatigue Life ◽  
Contact Fatigue ◽  
Critical Value ◽  
Fatigue Tests ◽  
Numerical Calculations ◽  
Quantitative Relation ◽  
Test Results ◽  
Contact Fatigue Life ◽  
Lubricant Viscosity ◽  
Film Lubrication

The paper considers the effect of lubricant viscosity, ν, on the contact fatigue life, N, in gearing applications. More than 40 sets of the thermal non-Newtonian EHL numerical calculations and six sets of disc fatigue tests under the conditions ranging from the mixed to full film lubrication are used. The results show that for improving gearing fatigue life it is generally useful to increase lubricant viscosity. But it is not simply the case that the higher the lubricant viscosity, the better. When lubricant viscosity, ν, is less than a critical value, νcr, a quantitative relation of is seen in the test results; When ν > νcr, however, increasing lubricant viscosity is found to reduce the fatigue life. Based on this result, the paper raises questions concerning the accuracy of the lubrication factor recommended by ISO/6336:1996.

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.

Contact Fatigue Tests and Contact Fatigue Life Analysis

2005 ◽  
Author(s):  
Hong Lin ◽  
Robert R. Binoniemi ◽  
Gregory A. Fett ◽  
Mick Deis
Keyword(s):  
Fatigue Life ◽  
Contact Fatigue ◽  
Fatigue Tests ◽  
Contact Fatigue Life ◽  
Life Analysis ◽  
Fatigue Life Analysis

Effect of Grain Flow Orientation on Rolling Contact Fatigue Life of AISI M-50

1982 ◽  
Vol 104 (3) ◽  
pp. 330-334 ◽  
Author(s):  
A. H. Nahm
Keyword(s):  
Fatigue Life ◽  
Flow Line ◽  
Flow Direction ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Vacuum Arc ◽  
Type I ◽  
Grain Flow ◽  
Contact Fatigue Life

Accelerated rolling contact fatigue tests were conducted to study the effect of grain flow orientation on the rolling contact fatigue life of vacuum induction melted and vacuum arc remelted (VIM-VAR) AISI M-50. Cylindrical test bars were prepared from a billet with 0, 45, and 90 deg orientations relative to billet forging flow direction. Tests were run at a Hertzian stress of 4,826 MPa with a rolling speed of 12,500 rpm at room temperature, and lubricated with Type I (MIL-L-7808G) oil. It was observed that rolling contact fatigue life increased when grain flow line direction became more parallel to the rolling contact surface.

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