Please choose your delivery country and your customer group
A series of tensile and strain controlled low-cycle fatigue tests were conducted at the temperatures ranging from room temperature (RT) to 900 deg C on a nickel-base heat-resistant alloy, Hastelloy XR-II, which is one of the candidate alloys for applications in the process heating high-temperature gas-cooled reactor (HTGR). Materials were tested in the solution annealed as well as in the pre-aged condition where aging consisted of isothermal exposure at 900 deg C for the period of 1000 h. In those tests the effects of aging and test temperature on tensile and fatigue properties were investigated. The ductility minimum point was observed near 600 deg C in the solution annealed condition. On the other hand, the ductility of the aged materials was reduced excessively at RT, and increased with increasing test temperature. At and below 700 deg C, the fatigue lives of the aged materials were shorter than those of the solution annealed ones. The tendency was interpreted through the fractographic and metallographic features of the fatigued specimens. The fatigue lives estimated from tensile properties using the method proposed by Manson were compatible with the results of fatigue tests under the test conditions employed. (ERA citation 13:015054)