A Study of the LCF Characteristics of the Ni-based Superalloy IN738LC

作者：Lee Dongkeun; Kang To; Koo Jae Mean; Seok Chang Sung^*; Song Sung Jin

来源：International Journal of Precision Engineering and Manufacturing, 2015, 16(4): 775-780.

DOI：10.1007/s12541-015-0102-5

• Superalloy
• IN738LC
• Low cycle fatigue
• Indentation
• Life prediction

In this study, low cycle fatigue (LCF) tests of IN738LC were conducted under high-temperature conditions. The tests were performed with various mechanical strain amplitudes and the relationship between strain amplitude and fatigue life was obtained. In addition, an equation for LCF life prediction was derived from the test results. After obtaining a strain-life diagram from the LCF test results, additional LCF tests were conducted according to the extent of damage. The LCF tests were taken at various degrees of damage in order to observe the change in mechanical properties the severity of damage. For this purpose, indentation tests were conducted and the relationship between hardness and damage was obtained. To nondestructively assess the low cycle fatigued IN738LC, the subharmonic nonlinearily parameter was first introduced because of the high attenuation properties of IN738LC. Until now, the subharmonic technique has been applied only to crack evaluation problems. This technique is presented as an effective tool for assessing low cycle fatigued IN738LC in this paper.

• 出版日期2015-4