국내 최대 기계 및 로봇 연구정보

기술보고서

기술보고서 게시판 내용
타이틀	Tensile Properties of LE-7 Engine Material with Welded Joints 3 rd Report Influence of Solution Treatment Conditions upon Micro Structures and Tensile Properties.
저자	Yoshiaki WATANABE, Tomoyuki Hashimoto, Makoto YOSHIDA
Keyword	Weldment; Micro Structure; Tensile Property; LE-7 Engine
URL	http://send.nal.go.jp/send/jpn/dlpdf.php3/naltr01285.pdf?id=NALTR0001285
보고서번호	NAL TR-1285
발행년도	1996.4
출처	NAL (National Aerospace Laboratory of Japan)
ABSTRACT	The H-II rockets have been successfully launched three times since its first success in February 1994,and Japan has established its own means of space transportation.The main engine of the H-II rocket,LE-7,uses many welded Inconel-718 joints.The hot section materials of teh LE-7 engine has suffered from severe thermal shock during the start and cut-off sequence,and these welded joints were the cause of many of the accidents during development.Hence,the welded joints were re-designed to increase the reliability of the LE-7 engine.Against this background,the authors studied the tensile properties of the GTA welded joint with solution treated at 1228 K and 1338 K in a previous report.This report shows the effects of solution treatment condn treatment condition study shows that the grain growth of the parent metal occurs rapidly in a very narrow window of time and temperature and that these phenomena are more sensitive to temperature than to time.This study also shows that the dissolution of teh Ni3Nb phase and the grain growth of the parent metal occur simultaneously.The tensile property test for different solution treatment conditions shows that the appropriate condition increases the ductility without loss of tensile strength partially dissolving the continuous Ni3Nb phase to a discrete one.