Tetsu-to-Hagane
Online ISSN : 1883-2954
Print ISSN : 0021-1575
ISSN-L : 0021-1575
Delayed Fracture under Repeating Stress in Various High Strength Steels
Mitsuo KIDOKeijiro NAKASAHideo TAKEI
Author information
JOURNAL FREE ACCESS

1979 Volume 65 Issue 5 Pages 535-541

Details
Abstract

The effect of superposition of small repeating stress on σsec the endurance stress under which no crack initiation occurs within 100h, and on the incubation time (time of crack initiation) has been investigated using notched specimens of four kinds of steels (JIS: SKD61, SNCM8, SUS420J2, and 18Ni mamging steel) quenched and tempered at various temperatures. The results obtained are as follows:
(1) For all the steels examined, the endurance stress σsec was not varied by the superposition of repeating stress when the stress amplitude, σa, was 2.5kg/mmmm2, when σa was larger than 5kg/mmmm2, however, σsec decreased with increase of σa.
(2) The amount of decrease ofσsec by the superposition of repeating stress seemed to be dependent not only on the yield strength of the materials but also on the stability of protective film on the notch surface against repeating stress and the intensity of metal-environment corrosion reaction after the destruction of the protective film by repeating stress. 18Ni maraging steel and SUS420J2 stainless steel with higher value of σsec under static stress revealed the smaller decrease of σsec under repeating stress than SKD61 and SNCM8 steels.

Content from these authors
© The Iron and Steel Institute of Japan
Previous article Next article
feedback
Top