Finite element analysis coupled with the continuum damage mechanics-based Kachanov–Rabotnov (KR) model has been carried out to describe the creep deformation and damage behaviour of 316LN austenitic stainless steel (SS) at 923 K under the uniaxial and multiaxial state of stress. Uniaxial creep experimental data have been used to optimize the material parameters of the KR model. The coupled differential equations are numerically integrated by fourth-order Runge–Kutta method in the USERCREEP subroutine and passed on to the Abaqus solver. 316LN SS exhibited notch strengthening effect under the multiaxial state of stress. Detailed analysis showed that stress distribution during creep deformation is localized to notch root due to the high constraint imposed by V-notch geometry. The estimated maximum value of the creep damage variable (ω) suggested that fracture is likely to initiate at the notch root location. Good agreement between experimental and predicted results has been observed for both plain and notch specimens.

进行了有限元分析，并结合基于连续损伤力学的Kachanov–Rabotnov（KR）模型来描述316LN奥氏体不锈钢（SS）在923 K单轴和多轴应力状态下的蠕变变形和损伤行为。单轴蠕变实验数据已用于优化KR模型的材料参数。耦合的微分方程通过USERCREEP子例程中的四阶Runge-Kutta方法进行数值积分，然后传递给Abaqus求解器。316LN SS在应力的多轴状态下显示出缺口增强作用。详细的分析表明，由于V型缺口几何形状施加了很高的约束，蠕变变形期间的应力分布局限于缺口根部。蠕变损伤变量的估计最大值（ω）提示断裂可能在缺口的根部位置开始。对于普通和缺口样品，实验结果和预测结果之间的一致性很好。