Fretting Fatigue of Some Nickel-Based Alloys in Steam Environment at 265°C

In comparison with plane fatigue, fretting damage may lead to a substantial decrease in the fatigue strength of the material due to the addition of alternating frictional stresses, and the continuous destruction of the surface oxide. Fretting fatigue and plain fatigue tests have been conducted to establish the effect of fretting on the fatigue strength of two nickel-based alloys, Inconel 600 and Incoloy 800 against carbon steel and 410S stainless steel, respectively. The tests were conducted in steam environment at 265°C. The main test variables were the contact pressure 0 < pc < 138 MPa and the mean stress 0 < σm < 138 MPa. The results of the S-N curves for plain and fretting fatigue tests indicated that the reduction factor in the fatigue strength of Inconel I-600 alloy due to fretting is in the range of 2.2 to 3.5, depending on the loading conditions. The results also showed that Incoloy I-800 is more susceptible to fretting fatigue than I-600 by approximately a factor of 1.5.