The effect of boron content, temperature, and neutron fluence on the mechanical properties of the modified type 304 stainless steels with boron

Tensile tests and J{dollar}sb{lcub}rm IC{rcub}{dollar} tests were performed on the NeutroSorb PLUS{dollar}sp{lcub}rm TM{rcub}{dollar} and the NeutroSorb{dollar}sp{lcub}rm TM{rcub}{dollar} series of boron containing modified type 304 stainless steels manufactured by Carpenter Technology Corporation. The steels include both wrought type and powder metallurgy type and are of various boron content. Test specimens were irradiated with neutrons to various fluence levels, i.e., 0, {dollar}5times10sp{lcub}15{rcub}, 1times10sp{lcub}17{rcub}{dollar} n/cm{dollar}sp2.{dollar} Tests were conducted at temperatures of {dollar}-{dollar}40, 75, and 500{dollar}spcirc{dollar}F (or 233, 298 and 533 K) to simulate various application temperature conditions. The tensile properties and the J toughness of the borated steels experienced little change after neutron irradiation. Limited temperature effects were found on the tensile properties and toughness of some borated steels, in both unirradiated and irradiated samples. The boron content in the steels was the most important factor affecting the mechanical properties. The powder metallurgy products show better mechanical properties and toughness than the cast and wrought products, mainly because of the refinement of the microstructure and the spheroidization of the boride particles. Analysis of the experimental results with emphasis on void formation process and radiation damage mechanism is provided. Experiment observations are explained through the analysis.