Investigation on the deformation and microstructure evolution of P91 steel in short-term small punch creep test

Abstract

Small punch creep test is a semi-destructive method which can be used for creep determination and assessment of the probability of failure. The deformation during this small punch creep test is very complicated because the accumulation of both plastic and creep deformation will lead to the failure. In order to understand the mechanism of small punch creep test from grain orientation changes during creep and fracture process, small punch creep test was carried out using P91 steel under a 500 N load at 600°C in this study. Finite element method was used to simulate the mechanical deformation process. Electron back-scattered diffraction technique and texture analysis were used to analyze the microstructure of the small punch creep deformation and rupture. The results showed that the grain orientation evolves from the rather random orientation in the first stage to the \110. //ND texture in the tertiary stage which caused mainly by shear strain.

Assessment of Creep Properties Using Small Punch Test for a 9%Cr-Mo-Co-B Power Plant Steel

“…In recent years, the small punch (SP) method has been introduced to the creep test by many researchers all over the world [12][13][14][15][16][17]. It is a quick laboratory test that uses miniature-sized specimens, usually a small disc with a diameter of 8-12 mm and thickness of 0.5 mm.…”