Influence of Contact Temperature on Contact Fatigue Failure Forms: Part 1—Contact Temperature Analysis of Rolling-Sliding Contact Specimen

1993 ◽  
Vol 115 (3) ◽  
pp. 466-470 ◽  
Author(s):  
Long-Qing Chen

Under rolling-sliding contact, specimens have different failure forms, such as pitting and spalling etc. The surface roughness of specimen in contact has a strong influence on the failure form. The elevated contact temperature produced by a rougher surface is one of the key factors in producing changes in failure form. According to the results of the test and the analysis, the following viewpoint is suggested to explain the influence of the roughness on failure forms: the rougher contact surface produces elevated contact temperature; the elevated contact temperature causes the material yield strength over local areas to reduce transiently thus resulting in a plastic deformation layer, and have the change of failure form. The present study includes two parts: in the first part, the analysis of contact temperature distribution is carried out; in the second part, the results of the test and analysis are discussed.

1993 ◽  
Vol 115 (3) ◽  
pp. 471-475 ◽  
Author(s):  
Long-Qing Chen

The surface roughness of contacting parts have a strong influence on the failure form of contact fatigue. Pitting failure is liable to occur on the contact parts with rougher surface. The present test shows that a plastic deformation layer (PDL) will generally occur beneath the race surface of the parts which fail in pitting; and the near-surface cracks will initiate in the plastic deformation layer, these cracks grow gradually and finally result in fatigue failure where the depth of the fatigue pit are 0.1–0.2 mm. According to the author’s analysis of contact temperature and contact stresses, the present paper suggests: when the race surface of rolling specimen is rough, the contact temperature rise reduces the transient yield strength of the metal below the maximum contact shear stress at this position, thereby, resulting in a plastic deformation layer.


2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110112
Author(s):  
Li Xun ◽  
Wang Ziming ◽  
Yang Shenliang ◽  
Guo Zhiyuan ◽  
Zhou Yongxin ◽  
...  

Titanium alloy Ti1023 is a typical difficult-to-cut material. Tool wear is easy to occur in machining Ti1023, which has a significant negative effect on surface integrity. Turning is one of the common methods to machine Ti1023 parts and machined surface integrity has a direct influence on the fatigue life of parts. To control surface integrity and improve anti-fatigue behavior of Ti1023 parts, it has an important significance to study the influence of tool wear on the surface integrity and fatigue life of Ti1023 in turning. Therefore, the effect of tool wear on the surface roughness, microhardness, residual stress, and plastic deformation layer of Ti1023 workpieces by turning and low-cycle fatigue tests were studied. Meanwhile, the influence mechanism of surface integrity on anti-fatigue behavior also was analyzed. The experimental results show that the change of surface roughness caused by worn tools has the most influence on anti-fatigue behavior when the tool wear VB is from 0.05 to 0.25 mm. On the other hand, the plastic deformation layer on the machined surface could properly improve the anti-fatigue behavior of specimens that were proved in the experiments. However, the higher surface roughness and significant surface defects on surface machined utilizing the worn tool with VB = 0.30 mm, which leads the anti-fatigue behavior of specimens to decrease sharply. Therefore, to ensure the anti-fatigue behavior of parts, the value of turning tool wear VB must be rigorously controlled under 0.30 mm during finishing machining of titanium alloy Ti1023.


1965 ◽  
Vol 87 (1) ◽  
pp. 177-184 ◽  
Author(s):  
R. A. Burton ◽  
J. C. Tyler ◽  
P. M. Ku

Experiments are reported wherein contact fatigue was brought about by the application of an oscillatory normal load between a ball and a flat specimen. Plots of the flat-specimen temperature versus time showed that a rapid temperature rise occurred in the initial stage of crack formation, and thus provided an early indication of fatigue. Thermal resistances were measured for the apparatus components as well as the specimen contact. Using these, it was possible to apply the measured flat-specimen temperature to obtain estimates of the contact temperature as well as the energy dissipation rate prior to the incidence of fatigue cracks. It was shown that the contact temperature did not rise sufficiently to produce annealing in the test specimens. Thus, toroidal rings of hardened and softened material in the stressed zone could not be attributed to thermal transformation of the bearing steel. It was also shown that energy dissipation due to cyclic loading varied in approximate exponential relationship with dynamic load, and decreased upon increase of static load when dynamic load was maintained constant.


2011 ◽  
Vol 86 ◽  
pp. 645-648 ◽  
Author(s):  
Lei Wang ◽  
Guang Liang Liu ◽  
Masanori Seki ◽  
Masahiro Fujii ◽  
Qian Li

In order to investigate the influence of different shot peenings on the rolling contact fatigue life of case−hardened steel, the thrust type rolling contact fatigue test was performed with a ball−on−disk contact tester. In this study, the case−hardened steel disks were treated by the fine particle peening with a shot diameter of 0.05 mm and the normal shot peening with a shot diameter of 0.30 mm. The surface hardness and the surface compressive residual stress of the test disks were increased by these peenings. On the other hand, the surface roughness of the test disks was increased by the normal shot peening, and was decreased by the fine particle peening. The rolling contact fatigue test showed that the rolling contact fatigue life of the test disks was improved by the fine particle peening, and was not improved by the normal shot peening. The rolling contact fatigue life of the test disks became longer as their surface roughness became smaller. Therefore, it follows from this that the fine particle peening, which can provide the increase in surface hardness and the decrease in surface roughness, is good for the increase in the rolling contact fatigue life of case−hardened steel.


Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 472
Author(s):  
Peijie Liu ◽  
Yanming Quan ◽  
Junjie Wan ◽  
Lang Yu

To guarantee the smooth operation of trains, rail grinding and wheel turning are necessary practices to remove surface defects. Surface integrity of machined wheel/rail materials is significant to affect their tribological performance. In this paper, firstly, the wheel specimens were turned by a CNC lathe and the rail specimens were ground by a cylindrical grinding machine with various machining parameters. Then, the wear and damage behavior of the machined wheel/rail discs was systematically investigated via a twin-disc wear testing apparatus under dry rolling-sliding condition. The experimental results show that the surface hardness of rail discs after machining is slightly higher than that of wheel discs, while the surface roughness and plastic deformation layer of wheel discs are much larger than those of rail discs. The surface hardness increase degree of rail discs and their thickness of plastic deformation layer are greater than those of wheel discs after the rolling-sliding test. The wear loss of wheel discs is much larger than that of rail discs. Surface roughness, hardness and plastic deformation layer of wheel/rail discs after machining exert a comprehensive effect on the wear behavior, and friction pair with appropriate original surface hardness and roughness generates the smallest amount of wear loss.


2019 ◽  
Vol 372 ◽  
pp. 451-462 ◽  
Author(s):  
Dong Tian-shun ◽  
Liu Li ◽  
Fu Bin-guo ◽  
Li Guo-lu ◽  
Wang Hai-dou ◽  
...  

2013 ◽  
Vol 199 ◽  
pp. 117-122
Author(s):  
Wojciech Labuda ◽  
Adam Charchalis

The article presents the research results referring to the analysis of the influence of finish treatment ( lathing, grinding, burnishing) on the contact fatigue of steel applied to marine pump shafts. The research was performed on a roller 40 mm in diameter made of 304L stainless steel. Within the research, the optimalization of burnishing technological parameters was conducted on account of the minimalization of Ra surface roughness coefficient as well as the maximalization of SU degree of surface layer relative hardness [. The multi criteria optimalization conducted by min-max method [ with regard to minimum surface roughness as well as maximum degree of surface layer hardness demonstrated that burnishing process should be carried out at the following technological parameters: burnishing force 1.1 kN, burnishing speed 35 m/min, feed 0.13 mm/rev. In addition, the influence of the burnisher passes number on the surface layer quality was determined [.The paper will present the research results of contact fatigue examination of samples after finish machining.


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