Nickel Precipitation on the Surface of 15-15Ti Stainless Steel with B₄C Exposed to Sodium

Abstract

In order to evaluate the application performance of B4C pellets as the neutron absorbing material for fast reactor, compatibility experiments were carried out at elevated temperatures for 15-15Ti stainless steel-sodium-B4C ternary system. Experiments results show that the nickel (Ni) precipitates on the inner surface of the 15-15Ti stainless steel (SS) tube. The Ni precipitates on the surface as island distribution, and with the increase of experiment time, the precipitations grow up. Experiment analysis show that the Ni precipitation process is caused by boronation of the Fe and Cr elements of the 15-15Ti SS tube.