Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
PRODUCTION OF HIGH TOUGHNESS SEAMLESS STEEL TUBE HAVING FINE-GRAINED STRUCTURE
Document Type and Number:
Japanese Patent JPH04358025
Kind Code:
A
Abstract:

PURPOSE: To produce a seamless steel tube having fine-grained structure and excellent in toughness by controlling steel components and hot rolling conditions, respectively.

CONSTITUTION: A billet of a steel which has a composition consisting of 0.05-0.2% C, 0.01-2.5% Si, 0.15-1.5% Mn, 0.005-0.1% Al, 0.005-0.1% Ti, 0.005-0.1% Nb, and the balance essentially Fe or further containing one or ≥2 kinds among Cr, Mo, Ni, V, rare earth elements, Ca, Co, and Cu and is heated up to ≥1200°C is subjected to hot piercing rolling, by which a tube stock is manufactured. Subsequently, the tube stock whose temp. is lowered to a temp. between Ar3 and Ar1 is heated up to a temp. of 900-1000°C higher than the above temp., finish-rolled at ≥(Ar3+50°C) finishing temp., and air-cooled, by which the high toughness seamless steel tube can be produced.


Inventors:
YAGI AKIRA
ASAHI HITOSHI
UENO MASAKATSU
SATO HISAMI
Application Number:
JP1669791A
Publication Date:
December 11, 1992
Filing Date:
February 07, 1991
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
NIPPON STEEL CORP
International Classes:
B21B19/04; C21D8/10; C21D9/08; C22C38/00; C22C38/14; (IPC1-7): B21B19/04; C21D8/10; C21D9/08; C22C38/00; C22C38/14
Domestic Patent References:
JPH0250916A1990-02-20
JPH01234521A1989-09-19
JPS62149814A1987-07-03
JPS5819432A1983-02-04
JPS59182920A1984-10-17
Attorney, Agent or Firm:
Hiroaki Tamura (1 outside)