A Study of TMF Characteristics of Ni-Base Superalloy IN738LC

• Published in: Applied Mechanics and Materials Vol. 598; no. Advanced Materials, Mechanics and Industrial Engineering; pp. 28 - 32
• Main Authors: Lee, Dong Keun, Lee, Jeong Min, Kim, Jae Won, Koo, Jae Mean, Seok, Chang Sung
• Format: Journal Article
• Language: English
• Published: Zurich Trans Tech Publications Ltd 01.07.2014
• Subjects: Blades; Fatigue (materials); Fatigue life; Fatigue tests; Hardness tests; High speed; Shutdowns; Turbine blades; IN738LC; Superalloy; In-Phase (IP); Out-Of-Phase (OP); Thermo-Mechanical Fatigue (TMF)
• ISBN: 9783038351795; 3038351792
• ISSN: 1660-9336; 1662-7482; 1662-7482
• DOI: 10.4028/www.scientific.net/AMM.598.28

A gas turbine blade operates under severe conditions including high temperature, high speed rotation, and frequent starts and shutdowns. Under such operating conditions, a blade is exposed to a thermo mechanical fatigue environment. These conditions shorten the life of the turbine parts and reduce the reliability of the gas turbine. Therefore, research on the characteristics of blade material is necessary. In this study, thermo-mechanical fatigue (TMF) tests were conducted for IN738LC, which is base a material for turbine blades. Tests were conducted under both the IP (in-phase) and OP (out of-phase) conditions, and tests results were compared in terms of fatigue life. After obtaining the ε-N curves, additional TMF tests were conducted according to variations in fatigue life. The purpose of the TMF test is to observe the change in mechanical properties of materials damaged during TMF and how these relate to fatigue life. For this purpose, an indentation test was conducted and the relationship between hardness and fatigue life were obtained.