Analysis of the Thermal Fatigue Cracking of 316L Model Pipe Components at Fast Reactor Temperatures

In order to assess the high-cycle thermal fatigue damage risk of the nuclear power plants mixing zones, the knowledge of the temperature fluctuations effect on the structure surface is necessary. To advance the accuracy and reliability of thermal fatigue load determination, a combined experimental and numerical investigation has been conducted on cylindrical components of 316L stainless steel subject to cyclic thermal shocks of varying intensity. Slightly different experimental conditions were applied in each test to explore the effect of DTmax values of increasing severity, addressing also higher temperatures typical for fast reactors, the effect of a superimposed static axial load to study the effect of a constant pressure on the thermal fatigue damage and a reduced test piece wall thickness. A comparison between thermal down-shock tests with and without additional constant tensile load and with different maximum temperatures are analysed in details here below.JRC.DDG.F.4-Safety of future nuclear reactor