Co 基超耐熱合金 HS-21 の粒界反応とクリープ破断特性
1985 年 71 巻 6 号 p. 727-734
詳細
1985 年 71 巻 6 号 p. 727-734
The effect of solution and aging treatment on the grain boundary reaction (GBR) as well as on the general precipitation in the interior of grain (GP) was investigated for Co-base superalloy HS-21. The GBR occurred during furnace-cooling after solution heating, and the maximum amount of it was obtained in the temperature range from 1 523 K to 1 548 K. The GBR that occurred during aging was considerably influenced by the cooling procedure after solution heating. A large amount of GBR was observed in the specimen directly quenched. In the air-cooled specimen, the amount of GBR was less than one half of that observed in the directly quenched one, while very few amount of it was observed in the water-quenched one. The extent of GP that occurred during aging was also affected by cooling procedure, and the maximum amount of it was obtained in the water-quenched one.
Creep rupture life was longer on the specimen with a small amount of GBR with GP. The improvement of rupture life resulted from the retardation of grain boundary sliding by the zigzag grain boundary owing to the GBR and by the increase of strength in the interior of grain due to the GP.
