Study on High Temperature Low-Cycle Fatigue Properties of 316FR Stainless Steel Weldment by Miniature Specimen

摘要

High temperature low-cycle fatigue tests were conducted by using a miniature specimen with diameter of 2mm and gage length of 3mm in order to investigate a detailed distribution of low-cycle fatigue properties in a welded joint of 316FR stainless steel. First, a high temperature low cycle fatigue testing procedure by miniature specimens was established. Five kinds of specimen were taken from the 316FR stainless steel welded joint of 50mm thick plate; one from the base metal, two from the heat affected zone with different hardness, and two from the weld metal in longitudinal and tangential directions. Low-cycle fatigue tests were carried out at 550 deg C at the strain rate of 0.1 percent/sec in air. Detailed low-cycle fatigue properties, such as fatigue strength, cyclic hardening/softening behavior and cyclic stress-strain curve, of the 316FR stainless steel welded joint were clarified.