Abstract
316LN stainless steel is the main material used in the primary pipelines of the pressurized water reactor due to its excellent characteristics. In the consideration of its serious environment, the cyclic deformation of material at high temperatures is concerned. A series of multiaxial ratcheting experiments were conducted at room, 350°C and 550°C. These experiments contained circular, rhombus and uniaxial loading paths with different mean stresses and stress amplitudes. At elevated temperature conditions, it got quick shakedown in multiaxial cases which is similar in uniaxial ones indicating that dynamic strain aging (DSA) exists. Uniaxial strain was the maximum in all the test temperature. Mean stress is seemed to be always the main influence factor. The difference of ratcheting strain under rhombus path and circular path decreased from room temperature to elevated temperature, which is inferred that DSA effect may weakened the nonproportionality at elevated temperature. The ratcheting strain evolution was simulated by Chen-Jiao-Kim model with the multiaxial parameter associated with temperature.
