Crack path and oxidation behavior during crack growth of alloy 617 in steam environment at 750 °C

Kosuke Araki, Masumi Yoshida, Yuji Ozawa, Yoichi Takeda, Susumu Nakano

Research output: Contribution to conferencePaper

Abstract

A high-efficiency coal-fired power plant, which is called an advanced ultra-supercritical (A-USC) plant, is being developed worldwide. For the high-temperature sections of A-USC plants, Ni-based superalloys are considered as candidate materials. Nowadays, particularly in Japan, renewable energy sources are widely promoted. Therefore, coal-fired power plants, including the A-USC plant, are expected to cover the need for load following operation to satisfy the electricity demand. However, it is expected that the output adjustment would induce fatigue damage in which the oxidation of material interacts. In this study, the crack growth behavior of alloy 617 in a steam environment at 750 °C was evaluated under cyclic loading. Under faster cyclic loading frequencies, the crack propagated perpendicularly to the loading direction. Under lower cyclic loading frequencies, the crack growth rates (CGRs) were accelerated and the crack paths were intergranular. Especially, in the intergranular crack, localized Al oxides were formed. It was thought that such intergranular oxides and precipitates affect the change in crack path depending on the applied loading frequency and result in differences between the CGRs.

Original languageEnglish
Pages1096-1100
Number of pages5
Publication statusPublished - 2020
Event7th International Conference on Power Engineering, ICOPE 2019 - Kunming, China
Duration: 2019 Oct 212019 Oct 25

Conference

Conference7th International Conference on Power Engineering, ICOPE 2019
CountryChina
CityKunming
Period19/10/2119/10/25

Keywords

  • A-USC
  • Crack growth behavior
  • Fatigue
  • Ni-based superalloy
  • Steam oxidation

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Fuel Technology
  • Energy Engineering and Power Technology

Fingerprint Dive into the research topics of 'Crack path and oxidation behavior during crack growth of alloy 617 in steam environment at 750 °C'. Together they form a unique fingerprint.

  • Cite this

    Araki, K., Yoshida, M., Ozawa, Y., Takeda, Y., & Nakano, S. (2020). Crack path and oxidation behavior during crack growth of alloy 617 in steam environment at 750 °C. 1096-1100. Paper presented at 7th International Conference on Power Engineering, ICOPE 2019, Kunming, China.