Materials Data Sheet Station

Last updated ：2010 / 7 / 8

Japanese version is here
　

Staff
Section Leader	Kazuhiro Kimura 　 Kiyoshi Kubo Masaharu Murata Fumiaki Matsumoto Toshio Ohba Hideaki Kushima Hiromichi Hongo Hideko Miyazaki Takashi Watanabe Masaaki Tabuchi Kota Sawada	Tatsuhiko Tanabe Kazushige Kamihira Masakazu Fujitsuka Hideo Tanaka Kenji Yokokawa Osamu Kanemaru Keishi  Nakano Shoko Taniguchi Wakako Moriiwa

MISSION and RESEARCH

■ MISSION ● Creep Data Sheet Project ： We play an important role in producing long-term creep data on creep resistant metallic  materials for power plants and petrochemical industries.

■ RESEARCH TOPICS 　We are promoting wide variety of investigations based on long-term creep data and creep exposed specimens longer than 100,000 hours obtained in the Creep Data Sheet Project. Recent topics on research activity are as follows. ●    Inherent creep strength Commercial heat resistant steels are strengthened by several kinds of precipitates. The precipitates coarsen during creep exposure, leading to decrease in strengthening effect of the precipitates on creep strength. As a result, the creep strength decreases to the strength originated from only matrix at long-term regions. The fundamental strength is “inherent creep strength”. Indeed, the inherent creep strength is found in ferritic steels. ●    Relationship between creep strength degradation at long term region and preferential recovery at the vicinity of prior austenite grain boundary in high chromium ferritic steels Creep strength of heat resistant steel decreases during creep exposure due to coarsening of precipitates and recovery of dislocation structure.  In many of heat resistant steels, the creep strength abruptly decreases at long term. The creep strength of modified 9Cr-1Mo steel abruptly decreases at more than 10,000h. The steel is strengthened by tempered martensitic lath structure, M23C6 carbide, MX carbonitrides and Laves phase. At long term regions, the martensitic lath structure preferentially recovers at the vicinity of prior austenite grain boundary. This is reason for the abrupt decrease of creep strength at long term regions. ●    Prediction of creep life for high temperature components We are trying to predict creep life for heat resistant steels by modified θ projection method, Iso-stress method and Region Splitting Analysis Method.

TOPICS

● Creep Data Sheets No.56 Preparation (2009.4.15) ● Creep Data Sheets No.54, 55 and Photograph Collection No.M-7 Preparation (2008.5.27) ● Creep Data Sheets No.53 and Photograph Collection No.M-6 Preparation (2007.5.25)　 ● Creep Data Sheets No.51, 52 and Photograph Collection No.M-5 Preparation (2006.5.10)　 ● Creep Data Sheets No.45A, 46A and Photograph Collection No.M-4 Preparation (2005.6.6)　 ● Creep Data Sheets No.50 and Photograph Collection No.M-3 Preparation (2004.4.14) ● ISO 9001 Introduced for NIMS Materials Data Sheets (2002.6.7)

　

　

【CONTACT】
PHONE　 +81-29-859-2229
FAX　　 +81-29-859-2830
E-mail: KIMURA.Kazuhiro@nims.go.jp

　

　

Materials Data Sheet Station