THE IRRADIATION-FATIGUE CAPSULE FOR A FATIGUE TEST OF MATERIAL AT THE RESEARCH REACTOR HANARO

摘要

An irradiation-fatigue capsule for a material fatigue test of a research reactor is provided to secure irradiation test data for material used in the reactor by repeatedly applying load to a test piece to measure displacement of the test piece. A heat medium(27c), a test piece assembly(20), and a load applying assembly(13) are inserted into an outer barrel(7). The test piece assembly has a test piece holder(23) coupled with screw threads of a test piece(26) and a spacer(25) between the test piece holder and a test piece gauge unit to facilitate heat transfer. A heater assembly(27) has a cylindrical main heater(27a) to heat the test piece at a desired temperature and an auxiliary heater(27b) around the main heater. A connector(19) is connected to the test piece holder exposed outside the main heater and has a check rod. An LVDT(Linear Variable Differential Transformer) receives a tensioned part of the test piece through the check rod. The load applying assembly has a yoke(16), a bellows unit(13a) contracted by pressure of helium gas injected from the yoke, and a bellows center rod(13b) connected to the yoke from an inner center of the bellows unit. A rod tip assembly(30) has a rod tip with a spring protrusion(31a) to limit a movement range, the lower guide spring inserted into the rod tip to support load of a capsule, a lower guide cap(34) to protect the rod tip and the lower guide spring, and a lower pin(35) to fix the lower guide cap to a lower outer surface of the outer barrel.