Seishin Kirihara

Effects of surface finishing on stress corrosion cracking of austenitic stainless steels in high temperature water

The intergranular stress corrosion cracking (IGSCC) susceptibility of surface finished type 304 and 304L stainless steels has been studied using a constant load tensile specimen in 288 °C water containing 26 ppm dissolved oxygen. The study was to define conditions to prevent IGSCC in piping used in a boiling water reactor (BWR). The results are as follows:1)IGSCC susceptibility of type 304 stainless steel increased markedly by surface finishing, such as grinding, when in a sensitized condition; increasing surface roughness shortened the time to failure.2)Type 304 stainless steel specimens, which are solution heat treated, do not show IGSCC susceptibility even if they are ground.3)Type 304L stainless steels do not show IGSCC susceptibility even if they are ground and sensitized at 621 °C for 2 h.