著者

長谷川 恵一 安藤 清 北出 正司 坂本 光正 福島 幸夫 沖田 耕一

出版者

一般社団法人日本機械学会

雑誌

日本機械学会論文集. A編 (ISSN:03875008)

巻号頁・発行日

vol.61, no.588, pp.1713-1718, 1995-08-25

参考文献数

8

被引用文献数

2

---

The LE-7 rocket engine main injector has undergone a few occurrences of welded joint structural failure because it is subjected to high thermal stress during the engine start and stop sequence. The low-cycle fatigue test and high-strain fatigue test which were conducted as part of failure analysis revealed that the welded joint has a considerably shorter fatigue life than expected. To improve the ductility and toughness of the welded joint, high-temperature-solution heat treatment was applied after welding. The low-cycle fatigue life of a welded joint subjected to this solution heat treatment became three times longer than that without it. A design criterion was established for low-cycle fatigue life estimation, and the life requirement was found to be satisfied.