Defect structures induced by inert-gases in rapidly solidified type 304 stainless steel

Abstract

Defects-are formed in most plastically deformed, quenched, and radiation damaged materials, and their type and distribution depend on the experimental conditions. Extensive research on radiation damage has shown that inert gases accumulate in materials and cause significant alterations of the microstructure and mechanical properties. In the centrifugal atomization process, the exposure of Type 304 stainless steel droplets to inert gas environments presents opportunities for their entrapment. The observation of large number density defects such as vacancy type dislocation loops and stacking faults in as-solidified Type 304 stainless steel powder is attributed to the inert gas/vacancy interaction.The purpose of this work is to examine the defect microstructure of extruded powder metallurgy (P/M) Type 304 stainless steel after preconditioning heat treatments at 900, 1000,1100, and 1200C for 1 hour followed by water quenching. Also, ingot metallurgy (l/M) Type 304 stainless steel (remnants of the feed stock for the powders) was heat treated at 1000 and 1100C for 1 hour followed by water quenching for comparison.