Spherical indentation creep characteristics and local deformation analysis of 310S stainless steel

To estimate the creep properties of 310S stainless steel reasonably, its spherical indentation creep characteristics and local deformation behaviour during vacuum indentation creep tests are analysed in this study. The influence of creep load, temperature, and indenter diameter on the indentation depth – time curve is discussed. The results indicate that the spherical indentation depth rate decelerates before becoming approximately constant. With an increase in creep load and temperature, there is an apparent increase in the creep depth rate. Along with the increase of creep deformation, the hardness value increases. Compression deformation can be observed at the specimen center under the indenter. With an increase in the distance from the specimen centre, the value of stress triaxiality on the upper surface of the specimen increases gradually. Unlike that at the specimen centre, a pile-up phenomenon along with tensile deformation feature is observed at the contact boundary. When the indentation creep depth is small, changes in the microstructure of the specimen are not obvious. Overall, the local deformation has an apparent influence within a distance of approximately twice the indenter radius from the contact boundary.