0
RESEARCH PAPERS

Evaluation of Thermal Aging Embrittlement in Directionally Solidified Ni-Base Superalloy by Small Punch Test

[+] Author and Article Information
Shin-ichi Komazaki1

Department of Materials Science and Engineering, Muroran Institute of Technology, 27-1 Mizumoto-cho, Muroran, 050-8585, Japankomazaki@mmm.muroran-it.ac.jp

Tetsuo Shoji, Kazumune Takamura

Fracture Research Institute, Graduate School of Engineering, Tohoku University, Aoba 01, Aramaki, Aoba-ku, Sendai, 980-8579, Japan

1

Corresponding author.

J. Eng. Mater. Technol 127(4), 476-482 (Apr 05, 2005) (7 pages) doi:10.1115/1.2019983 History: Received February 27, 2004; Revised April 05, 2005

In order to develop a procedure for evaluating the degradation of impact toughness in directionally solidified Ni-base superalloy CM247LC, which is commonly used for advanced gas turbine blades, the change in small punch (SP) fracture energy due to thermal aging has been investigated. The SP testing technique has been applied to materials aged under various aging conditions, and correlation with the results of Charpy V-notch impact tests has been examined. The experimental results reveal that SP fracture energy at room temperature decreases with aging at 800 °C and is uniquely correlated with high-temperature Charpy impact toughness. The current experiment has shown that the SP testing technique is useful in evaluating the degree of thermal aging embrittlement, one of the parameters required for remaining-life prediction of aged components.

Copyright © 2005 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 3

Loading and specimen support configuration for SP test

Grahic Jump Location
Figure 4

Microstructures of vicinities of grain boundaries of (a) as-received material and (b) material aged at 850 °C for 10,000 h

Grahic Jump Location
Figure 5

Change in Charpy impact absorbed energy plotted as a function of Larson-Miller parameter

Grahic Jump Location
Figure 6

Optical and SEM micrographs of fracture surface of material aged at 850 °C for 10,000 h. The casting direction is perpendicular to the fracture surface.

Grahic Jump Location
Figure 7

Examples of facet and microstructure observed on material aged at 800 °C for 10,000 h. The casting direction is perpendicular to the fracture surface.

Grahic Jump Location
Figure 8

Cross-sectional surfaces of material aged at 900 °C for 10,000 h

Grahic Jump Location
Figure 9

Change in Vickers hardness plotted against Larson-Miller parameter

Grahic Jump Location
Figure 10

Vertical section of fracture surface of material aged at 900 °C for 10,000 h

Grahic Jump Location
Figure 11

Change in size distribution of MC carbide with thermal aging

Grahic Jump Location
Figure 12

Change in load-deflection curve with thermal aging

Grahic Jump Location
Figure 13

SP specimen surfaces of (a) material aged at 800 °C for 3000 h and (b) as-received material tested at room temperature

Grahic Jump Location
Figure 14

Effect of testing temperature on load-deflection curve of material aged at 800 °C for 10,000 h

Grahic Jump Location
Figure 15

Temperature dependence of SP energy measured on as-received material and material aged at 800 °C for 10,000 h

Grahic Jump Location
Figure 16

Relationship between SP energy at RT and Charpy impact absorbed energy at 850 °C

Grahic Jump Location
Figure 17

Comparison of measured CVNE with calculated one by Eq. 2

Grahic Jump Location
Figure 2

SEM micrograph of γ′ phase of as-received material

Grahic Jump Location
Figure 1

Schematic illustration and optical micrograph of DS slab and extraction of SP specimen from fractured Charpy impact specimen

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In