Title:
MANUFACTURE OF SEAMLESS STEEL TUBE FOR CONSTRUCTION USE, EXCELLENT IN REFRACTORINESS
Document Type and Number:
Japanese Patent JP3429156
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To simplify the manufacturing process of a seamless steel tube excellent in refractoriness and to attain energy saving.
SOLUTION: A billet, which has a composition containing 0.04-0.15% C, ≤0.5% Si, 0.5-2.0% Mn, 0.1-1.0% Mo, ≤0.010% Al, ≤0.012% N, and one or more kinds among 0.01-0.10% V, 0.01-0.04% Nb, and 0.1-0.5% Cr, further containing the active N, obtained by equation (active N)(%)=N(%)-[1/2×Al(%)], by ≥0.002%, and having the balance Fe with inevitable impurities, is heated and subjected to hot piercing and rolling, by which the seamless steel tube is manufactured. At this time, in succession to piercing, finish rolling is performed at ≥900°C finishing temp. and ≥40% reduction of area, and the resultant steel tube is reheated, without cooling, up to 900 to 1000°C, air-cooled, and then temperature at 500 to 700°C. By this method, energy saving can be attained by the simplification of the process and the improvement of efficiency, and the seamless steel tube excellent in refractoriness ca be inexpensively manufactured.
Inventors:
Keisuke Ichiryu
Toshiharu Abe
Toshiharu Abe
Application Number:
JP9797497A
Publication Date:
July 22, 2003
Filing Date:
March 31, 1997
Export Citation:
Assignee:
SUMITOMO METAL INDUSTRIES,LTD.
International Classes:
B21B17/00; C21D8/10; C22C38/00; C22C38/12; C22C38/38; (IPC1-7): C21D8/10; B21B17/00; C22C38/00; C22C38/38
Domestic Patent References:
| JP4297523A | ||||
| JP3249149A | ||||
| JP5105947A | ||||
| JP5320753A | ||||
| JP480350A | ||||
| JP9184043A | ||||
| JP5121933B1 |
Attorney, Agent or Firm:
Shigenobu Ikejou (1 person outside)