The effect of in-beam cycling on the high cycle fatigue behaviour of type 316 L stainless steel

Abstract

The effect of deuteron irradiation on the fatigue life of type 316 L stainless steel was studied for both in-beam and post-irradiation conditions in the high cycle fatigue (HCF) range. Torque controlled fatigue tests were performed in torsion on hour glass shaped specimens at a temperature of 400°C during and after an irradiation with 19 MeV deuterons at a beam intensity which corresponds to circa 5 × 10⁻⁶ dpa/s. The data are analysed with the aid of a fatigue damage model. The analysis reveals that:

1. i. for the imposed stress range, the irradiation increased the fatigue lifetime by a factor of 5–7

2. the extension in the fatigue life was greater for in-beam cycling than for post-irradiation cycling

3. iii. the fatigue crack growth rate was equal for both in-beam and post-irradiation conditions.

Key words:

• high cycle fatigue
• in-beam cycling
• fatigue damage
• crack growth
• type 316 L stainless steel