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Title:
MANUFACTURE OF TITANIUM ALLOY SEAMLESS TUBE
Document Type and Number:
Japanese Patent JPH03211261
Kind Code:
A
Abstract:

PURPOSE: To obtain a tube excellent in both strength and ductility only by annealing treatment, at the time of manufacturing a tube by an inclined rolling method, immediately after the end of hot rolling, rapidly cooling the rolled stock from a specified high temp. in the stage of the working and specifying the conditions of heat treatment executed after that.

CONSTITUTION: The outlet temp. of a final rolling mill in the stage of hot rolling is regulated to the one from the β transus+200°C to the β transus-150°C. Moreover, immediately after the rolling, the rolled stock is cooled to a room temp. at ≥1%oC/sec cooling rate and is then annealed at 450 to 800°C for 15min to 8hr. As for the outlet temp. of the final rolling mill, in the case of more than the upper limit, the crystalline grains are coarsened to deteriorate its ductility, and in the case of less than the lower limit, a hardening effect can not be obtd. even if cooling treatment is executed after that, so that its strength can not be improved. As for the cooling treatment, in the case of <1°C/sec, the hardening effect at the time of temp.-reducing can not be shown. Furthermore, as for the temp. in the stage of the annealing, in the case of less than the lower limit, the elongation of a product is made low, and in the case of more than the upper limit, a strengthening effect can not be shown. As for the annealing time, in the case of less than the lower limit, its ductility is made low, and in the case of more than the upper limit, its strength is remarkably deteriorated.


Inventors:
Kuroda, Atsuhiko
Okada, Minoru
Application Number:
JP1990000007625
Publication Date:
September 17, 1991
Filing Date:
January 17, 1990
Export Citation:
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Assignee:
SUMITOMO METAL IND LTD
International Classes:
B21B19/02; B21B23/00; C22F1/00; C22F1/18; (IPC1-7): B21B19/02; B21B23/00; C22F1/18



 
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