J Mater Sci Technol ›› 2002, Vol. 18 ›› Issue (02): 176-180.

• Research Articles • Previous Articles     Next Articles

Thermal-Mechanical Fatigue Behavior and Life Analysis of Cast Ni-base Superalloy K417

Hui ZHANG, Yuechen WANG, Feng LIU, Suhua AI, Qishan ZANG, Zhongguang WANG   

  1. Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
  • Received:1900-01-01 Revised:1900-01-01 Online:2002-03-28 Published:2009-10-10
  • Contact: Hui ZHANG

Abstract: In-phase (IP) and out-of-phase (OP) thermal-mechanical fatigue (TMF) behavior of cast Ni-base superalloy K417 was studied. All experiments were carried out under total strain control with temperature cycling between 400~850℃. Both in-phase and out-of-phase TMF specimens exhibited cyclic hardening followed by cyclic softening at the minimum temperature. Besides, they cyclically hardened in the early stage of life followed by cyclic softening at the maximum temperature. OP TMF life was longer than that of IP TMF. Various damage mechanisms operating in different controlled strain ranges and phasing were discussed. A few life prediction methods for isothermal fatigue were used to handle TMF fatigue and their applicability to superalloy K417 was evaluated. The SEM analysis of the fracture surface showed that transgranular fracture was the principal cracking mode for both IP and OP TMF. Oxidation was the main damage mechanism in causing shorter fatigue life for IP TMF compared with OP TMF.

Key words: Thermal-Mechanical fatigue, Life analysis Superalloy