1993 年 42 巻 482 号 p. 1312-1318
In order to investigate the crack growth characteristics by thermal striping in sodium coolant used for FBR, the thermal striping tests in sodium have been conducted by using Type 304 stainless steel and its carburized material.
The stress intensity factor, derived from the thermal stress analysis for the condition of plane stress, was effective for the estimation of the final crack length. It was found that the number of cycles, at which the cracks were produced in the carburized material, was smaller than that in the base metal. The final cracks in the carburized material were longer than those of the base metal. The loading condition of the termal striping was controlled by thermal strain, and the damage by thermal striping in a brittle material such as the carburized material was greater than the base metal. The range of stress intensity factor of the carburized material was increased by the change of property.