The effect of ionic nitriding on the fatigue limit of steel 38KhMYuA

1974 ◽  
Vol 8 (6) ◽  
pp. 733-734 ◽  
Author(s):  
O. I. Butenko ◽  
V. B. Dalisov ◽  
Yu. M. Lakhtin ◽  
V. I. Pokhmurskii ◽  
A. M. Shlyafirner
Author(s):  
Daniel Oliveira ◽  
Artur Dias ◽  
Cainã Bemfica de Barros ◽  
Fábio Castro ◽  
Roberto Costa
Keyword(s):  

2020 ◽  
pp. 339-342
Author(s):  
V.F. Bez’yazychny ◽  
M.V. Timofeev ◽  
R.V. Lyubimov ◽  
E.V. Kiselev

The theoretical justification for the hardening process of the surface layer of machine parts for combined methods of surface hardening with subsequent application of strengthening coatings, as well as reducing or increasing the fatigue limit due to the fretting process is presented.


2018 ◽  
Vol 165 ◽  
pp. 04011
Author(s):  
Keisuke Tanaka ◽  
Yuta Murase ◽  
Hirohisa Kimachi

The effect of micro-notches on the fatigue strength of nickel thin films was studied. Two types of thin films with 10 μm thickness were produced by electrodeposition using sulfamate solution without and with brightener: ultra-fine grained film (UFG) with the grain size of 384 nm and nano-crystalline grained film (NCG) with that of 17 nm. Micro-sized notches introduced by FIB had the width of 2 μm and various depths from 8 to 150μm. Fatigue tests were conducted under the stress ratio of 0.1. The fatigue strength decreased with increasing depth of notches. NCG had much higher strength than UFG compared at the same notch depth. Notches as small as 8μm did reduce the fatigue strength of both UFG and NCG. The fatigue limit was controlled by the initiation of cracks and no non-propagating crack was observed in specimens fatigued below the fatigue limit. A model of fictitious crack successfully predicted the reduction of the fatigue limit due to micro-notches. The characteristic crack length of NCG was much smaller than the UFG, while the fatigue strength of defect-free NCG was larger than that of UFG. SEM observation of fracture surfaces was conducted to reveal micromechanisms of fatigue crack initiation.


2002 ◽  
Vol 45 (2) ◽  
pp. 290-297 ◽  
Author(s):  
Katsuyuki MATSUI ◽  
Hirohito ETO ◽  
Katsuya YUKITAKE ◽  
Yoshitaka MISAKA ◽  
Kotoji ANDO

2011 ◽  
Vol 295-297 ◽  
pp. 2227-2230
Author(s):  
Cong Ling Zhou

In this study, fatigue tests have been performed using two kinds of specimens made of 25 steel. One is pre-strained specimen with pre-strain ratio changing from 2% to 8% by tension, the other is roller worked with deformation of 0.5 mm and 1.0 mm in diameter direction. In the case of pre-strained specimen, the fatigue limit increases according to increase of tensile pre-strain, the fatigue limit of 8% pre-strained specimen is 25% higher than that of non-pre-strained one; in the case of roller worked specimen, the fatigue limit of R05 and R10 is 126% and 143% to that of non-roller worked specimen, respectively. These remarkable improvements of fatigue limit would be caused by the existence of compressive residual stress, work-hardening and the elongated microscopic structures.


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