Volume 5, Issue 4 (April 2008)
Application of the Small-Punch Test to Irradiated Reactor Vessel Steels in the Brittle-Ductile Transition Region
In this paper, a method is applied for the identification of hardening parameters in the brittle-ductile transition region and the determination of Weibull parameters in the brittle region using small-punch tests. A small-punch-test device is developed to measure the load-displacement curve for non-irradiated and irradiated specimens of a reactor vessel steel at different temperatures inside a hot cell. In a global optimization algorithm for the identification of hardening properties, time-consuming finite element method (FEM) calculations are avoided by using neural networks that were trained with the help of a database previously generated by FEM. Identified material properties are compared with data from tensile tests, where available. The influence of irradiation and temperature on the material and fracture behavior is analyzed.