scholarly journals MODELS OF PHYSICALLY SHORT AND MACROSCOPIC CRACK DEVELOPMENT AND THEIR APPLICATION FOR TIN BASED BABBIT

2019 ◽  
Vol 2019 (5) ◽  
pp. 4-14
Author(s):  
Михаил Зернин ◽  
Mikhail Zernin

The stages of fatigue crack development are analyzed. The well-known models of physically short cracks and generalized models describing some stages are shown. A perspectivity of a statistical generalized model offered is shown. The parameters obtained of a cyclic crack resistance of tin-based babbit are presented.

2008 ◽  
Vol 144 ◽  
pp. 90-93 ◽  
Author(s):  
Grzegorz Gasiak ◽  
Grzegorz Robak

The paper presents a test stand for measurements of fatigue crack propagation. The stand includes a fatigue machine MZGS–100 and a device for registration of the crack length. The test stand is equipped with a stereoscopic microscope with fluent magnification of 7× – 67.5×. The microscope can be applied for observation of fatigue crack development. The microscope is also equipped with a digital camera, which enables continuous observation of fatigue crack development on the computer monitor and it is not necessary to stop the machine. The test results obtained at this stand can be used for determination of fatigue life and fatigue crack propagation rate.


1974 ◽  
Vol 7 (6) ◽  
pp. 668-670
Author(s):  
D. V. Lebedev ◽  
B. M. Ovsyannlkov

1983 ◽  
Vol 15 (5) ◽  
pp. 691-695
Author(s):  
V. A. Stepanenko ◽  
N. N. Sultani ◽  
V. V. Khil'chevskii ◽  
Yu. M. Shemegan

1990 ◽  
Vol 22 (4) ◽  
pp. 496-503
Author(s):  
V. V. Larionov ◽  
M. G. Selyantsev

1975 ◽  
Vol 7 (10) ◽  
pp. 1184-1187
Author(s):  
V. T. Troshchenko ◽  
V. V. Pokrovskii

2014 ◽  
Vol 31 (4) ◽  
pp. 305-314 ◽  
Author(s):  
W-. T. Yan ◽  
S. Holdsworth ◽  
I. Kühn ◽  
E. Mazza

Author(s):  
О. Yu. Vytyaz ◽  
R. S. Hrabovskyi

The aim of the proposed article is to determine the patterns of the corrosion-fatigue cracks in long-term operational metal elements of drill strings (steel 45, 36G2S, 40HN) when drilling wells in corrosive environments (drilling fluid "Biocar", potassium polymer mud and on the air). Based on the obtained results of experimental studies, diagrams of cyclic corrosion crack resistance for the studied systems "metal - medium" were drawn. The cyclic crack resistance characteristics of long-used metals of drill string elements are determined - the values of constants (C and n) in power dependence of Paris, as well as the values of threshold and critical stress intensity factory. The influence of drilling mud of the corrosion crack resistance of the investigated metals of drill string elements was estimated quantitatively. In particular, in the environment of drilling mud "Biocar" the process of corrosion-fatigue crack development in the studied metals of the elements of drill strings is not significantly, in the range of 1-5%, differs from the development of fatigue crack on the air. Whereas in the potassium polymer drilling mud media, the rate of corrosion-fatigue cracks development in the investigated metals of the drill strings elements significantly, in the range of 15-35%, differs from the development of fatigue cracks on the air. It is established that under the influence of working loads the process of the corrosion-fatigue crack development in long-operated elements of drilling string is accelerated by more than 10% in the media of the potassium polymeric drilling mud than in the environment of drilling mud "Biocar".


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