研究論文
強じんマルエージ鋳鋼の強度とじん性の異方性について
1982 年 54 巻 2 号 p. 119-124
詳細
1982 年 54 巻 2 号 p. 119-124
Effects of stress applied along the columnar growth direction and heat treatment on mechanical properties of unidirectionally solidified 18%Ni maraging steel were investigated. The main results obtained were as follows:
(1) When the stress is applied parallel to the direction of columnar growth, the strength, ductility and toughness are a little higher than those with stress applied to the perpendicular direction.
(2) A four-step heat treatment including homogenization resulted in increased strength and decreased ductility, whereas the anisotropy of the mechanical properties was reduced.
(3) A very high Charpy V-notch test value of 20 kg·m/cm2 was obtained with specimens parallel to the growth direction after a two-step heat treatment without homogenization.
(4) Heavy segregation of Mo accompanying dendritic solidification was reduced by the four-step heat treatment. Microhardness difference between dendritic and interdendritic regions remained after the two-step heat treatment, because the segregation effect was retained. Thus, the behavior of the specimens parallel to the growth direction was like that of the “in situ composite” with a ductile phase and a strong phase.
