# Fileset

[Fatigue2022_Abstract_Nobuo Nagashima.pdf](https://mdr.nims.go.jp/filesets/cf1bb2ab-dbd2-434f-8783-15e541d5a77b/download)

## Creator

[長島 伸夫](https://orcid.org/0000-0003-3588-980X), [早川 正夫](https://orcid.org/0000-0001-5143-8350), 長井 寿, 升田 博之, 中西栄三郎, 中西宣文, 岩崎勝

## Rights

[In Copyright](http://rightsstatements.org/vocab/InC/1.0/)

## Other metadata

[Fatigue strength evaluation of 1180MPa class recycled steel](https://mdr.nims.go.jp/datasets/081dfb3d-4a5e-4460-b012-de5808d89499)

## Fulltext

Microsoft Word - fatigue2022 naga13th International Fatigue Congress (FATIGUE2022+1) November 6th to 10th, 2023－Hiroshima, JAPAN Fatigue strength evaluation of 1180MPa class recycled steel  Nobuo NAGASHIMA1, Masao HAYAKAWA1, Kotobu NAGAI1, Hiroyuki MASUDA1,  Eizaburo NAKANISHI2, Noriyuki NAKANISHI2, Masaru IWASAKI2  1 National Institute for Materials Science, JAPAN  2 Tokyo Steel Manufacturing Co. LTD. JAPAN  * Corresponding author: NAGASHIMA.Nobuo@nims.go.jp   ABSTRACT:  The present study investigated the material properties of 1180MPa class recycled steel fabricated from waste scraps to evaluate the required performance of parts as steel sheets for automobiles. The recycled steel showed a strength-ductility performance: tensile strength of 1234 MPa, total elongation of 18%, stretch-frangibility λ of 21%, limiting dome height of 12.2 mm, and limiting drawing ratio of 2.09%. In the fatigue test with a stress ratio R = -1, the mirror finish material had a fatigue limit of 600 MPa at 107cycles to failure for both bending load and axial load. The fatigue limit corresponds to half tensile strength that is believed to be the maximum fatigue limit in cases of surface initiation of fatigue. The fatigue limits obtained by changing the stress ratio under bending load well matched the corrected goodman line. Therefore, the effect of average stress can be reliably evaluated from the fatigue limit diagram. In this way, the 1180MPa class recycled steel sheet has high fatigue strength with sufficient reliability and satisfactory meets the required performance of parts as a steel sheet for automobiles.  KEYWORDS:  high-strength recycled steel; 107 cycles fatigue limit; stress ratio; fatigue limit diagram   Reference N. NAGASHIMA1, M. HAYAKAWA, K. NAGAI, H. MASUDA, E. NAKANISHI, N. NAKANISHI, M. IWASAKI, Vol.53, No.4, p.808-814, Transuctions of Society of Automotive Engineers of Japan.          Fig. 1 S-N curves obtained under stress ratio of R = -1. 104 105 106 107 10840050060070080090010001180MPa Recycled steelR=-1, Room temperatueNumber of cycles to failure Nf  (cycles)Stress amplitude σa  (MPa)polished surface  Plane bending Axial loadingAs pickled steel Plane bending Axial loading