Probable reasons for the nucleation of a fatigue crack are shown for asymmetric constant-sign bending on the inner surface during the test of hollow cylinder parts made from hot-rolled tubes. It is shown that the decrease of the roughness of the inner surface to Rmax≤10 μm in combination with the structure of the outer layer (martensite + troostite- martensite) at a depth of 2 mm creates conditions for a maximal increase in the durability of hollow parts under different kinds of loading.

Topics
Alloys, Crack initiation and detection, Educational assessment
1.
A. D.
 
Zasypkin
 and
V. B.
 
Dementyev
,
Izvestiya Vuzov. Mashinostroenie
 
4
,
62
–
67
(
2000
).
Google Scholar
 
2.
O. I.
 
Shavrin
,
V. B.
 
Dementyev
,
L. N.
 
Maslov
, and
A. D.
 
Zasypkin
,
The Quality of the Surface of Thermomechanically Hardened Tubular Products
(
IPM UrO RAN Publ.
,
Izhevsk
,
2006
).
Google Scholar
 
3.
V. B.
 
Dementyev
 and
A. D.
 
Zasypkin
,
Vestnik IzhGTU
 
3
,
20
–
22
(
2001
).
Google Scholar
 
4.
O. I.
 
Shavrin
,
A. D.
 
Zasypkin
, and
V. B.
 
Dementyev
,
Traktory i Selkhozmashiny
 
8
,
16
–
18
(
1999
).
Google Scholar
 
5.
V. B.
 
Dementyev
 and
A. D.
 
Zasypkin
, “
On the reasons of the center of failure on the inner surface of hollow pins for tracks of tracked vehicles
,” in
Mechanics and Control Processes. Proceedings of the XXXVII Ural seminar devoted to 150 years since K. E. Tsyolkovsky’s birth, 100 years since S. P. Korolyev’s birth and the 60ᵗʰ anniversary of the Academician V. P. Makeyev State Rocket Center
(
UrO RAN Publ.
,
Ekaterinburg
,
2007
).
Google Scholar
 
6.
V. B.
 
Dementyev
,
O. I.
 
Shavrin
,
L. N.
 
Maslov
, and
A. D.
 
Zasypkin
,
The Quality of Track Pins as a Basis for the Reliability and Durability of Caterpillars
(
IPM UrO RAN Publ.
,
Izhevsk
,
2009
).
Google Scholar
 
7.
A. D.
 
Zasypkin
,
Traktory i Selkhozmashiny
 
7
,
38
–
41
(
2010
).
Google Scholar
 
This content is only available via PDF.
© 2019 Author(s).
2019
Author(s)