抄録
Two sets of bellows type expansion joints were tested using a sodium test apparatus. After this test being done, mechanical and metallurgical examinations were performed.
The bellows of these joints are of a single ply welded type. Each joint has two bellows, one of which contacts directly with sodium forms a pressure boundary, and the other is installed as a backup of the former one.
The test was conducted at 500°C and 2 atg of sodium temperature and pressure respectively, and 26, 600 cycles of expansion and contraction were continued alternatively for 700 hr in succession. During this test, neither leak nor deteriorated point were found.
After the sodium test, mechanical and metallurgical examination such as strength of welded parts, chemical composition, electro structure and X-ray analysis were conducted. In this examination, a slight carburization and decromium were found, however, we would not believe that it will lead to a definite fault.
