Document Type and Number:
Japanese Patent JPH0344275
Kind Code:
B2
Abstract:
A method of producing cladding tube comprises a step of temperature-gradient annealing in which the inner surface of the tube is heated to a temperature higher than the recrystallization temperature thereof, while the outer surface of the tube is cooled, after the tube has been hot-extruded. The temperature-gradient annealing is effected while a temperature gradient is maintained between the inner surface and the outer surface of the cladding tube. While keeping the inner surface at a temperature higher than the recrystallization temperature, and the outer surface at a temperature lower than the recrystallization temperature. The cladding tube is obtained with the outer surface which has an excellent resistance to nodular corrosion and a soft inner surface which has an excellent resistance to stress corrosion cracking.
Inventors:
TAKASE IWAO
YOSHIDA SUMI
IKEDA SHINZO
MASAOKA ISAO
NAKAJIMA JUNJIRO
YOSHIDA SUMI
IKEDA SHINZO
MASAOKA ISAO
NAKAJIMA JUNJIRO
Application Number:
JP1998084A
Publication Date:
July 05, 1991
Filing Date:
February 08, 1984
Export Citation:
Assignee:
HITACHI LTD
International Classes:
C22C16/00; C22F1/18; G21C3/06; G21C3/07
Next Patent: JPH0344276