지르코늄합금 튜브의 냉간 필거링 특성 평가

The property of zirconium alloy is well known to be influenced by pilgering pass schedule and its tooling; thus the control of its microstructure and mechanical property in the final tube product for nuclear fuel applications is a major concern of tube manufacture. To make final tube, the 3 passes pilgering is applied in general by using TREX(Tube Reduced EXtrusion), 63.5㎜ outer diameter(OD), in KEPCO NF and most of Zr tube manufacturing companies. They are also taking big efforts to reduce pilgering step for the sake of increasing the efficiency of production in the forming stage of tube. The objective of this study is to develop 2 passes of pilgering schedule from the conventional 3 passes of pilgering schedule for manufacturing the dash pot tube conforming to specification, which is newly developing component for the advanced nuclear fuel assembly in KEPCO NF.