2024-03-29T07:14:53Z
https://soar-ir.repo.nii.ac.jp/oai
oai:soar-ir.repo.nii.ac.jp:00012328
2022-12-14T04:05:59Z
1221:1222
Notch-fatigue Strength of Advanced TRIP-aided Martensitic Steels
Kobayashi, Junya
Yoshikawa, Nobuo
Sugimoto, Koh-ichi
Copyright© 2013 The Iron and Steel Institute of Japan
notch-fatigue strength
notch sensitivity
ultrahigh-strength steel
TRIP-aided steel
martensite
retained austenite
M-A constituent
The notch-fatigue limit and notch sensitivity of 0.1-0.6%C-1.5%Si-1.5%Mn transformation-induced plasticity (TRIP)-aided martensitic steels (TM steels) were investigated for use as common rails in next-generation automotive diesel engines. Also, these properties were related to the microstructural and retained austenite characteristics. When TM steels containing 0.2% to 0.4% C were subjected to heat treatment for isothermal transformation at 50 degrees C and subsequent partitioning at 250 degrees C, the steels achieved much higher notch-fatigue limits and lower notch sensitivities than those of conventional 0.2-0.4%C-1.0%Cr-0.2%Mo structural steels. This was principally associated with (i) plastic relaxation of localized stress concentration as a result of strain-induced transformation of 3-5 vol% metastable retained austenite and (ii) a large amount of finely dispersed martensite-austenite phase along prior austenitic, packet and block boundaries, as well as (Hi) a small amount of carbide only in the wide lath-martensite structure, which may contribute to making fatigue crack initiation and/or propagation difficult.
Article
ISIJ INTERNATIONAL. 53(8):1479-1486 (2013)
IRON STEEL INST JAPAN KEIDANREN KAIKAN
2013
eng
journal article
VoR
http://hdl.handle.net/10091/17702
https://soar-ir.repo.nii.ac.jp/records/12328
https://doi.org/10.2355/isijinternational.53.1479
10.2355/isijinternational.53.1479
0915-1559
AA10680712
ISIJ INTERNATIONAL
53
8
1479
1486
https://soar-ir.repo.nii.ac.jp/record/12328/files/Notch-fatigue_Strength_Advanced_TRIP-aided.pdf
application/pdf
2.6 MB
2015-09-28