Title:
PRODUCTION OF 400N STEEL FOR CONSTRUCTION USE, EXCELLENT IN REFRACTORINESS
Document Type and Number:
Japanese Patent JP3739893
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To obtain a refractory steel material for construction use, excellent in high temp. strength, by controlling the value of bainite parameter DB to a value in a specific range and subjecting the steel to high temp. heating/high temp. rolling and then to air cooling.
SOLUTION: A steel, having a composition which consists of, by weight ratio, 0.005-0.04% C, ≤0.3% Si, 0.5-1.0% Mn, ≤0.015% P, ≤0.015% S, 1.0-1.3% Mo, 0.01-0.05% Nb, 0.005-0.02% Ti, ≤0.10% Al, 0.001-0.006% N, and the balance essentially Fe and in which the value of DB in the equation, as the product of alloying elements, is regulated to 0.4-0.5, is reheated to 1100-1300°C and hot plastic working is finished at 850-1000°C and then air cooling is applied down to the ordinary temp., by which microstructure is formed into a structure composed essentially of bainite. By this method, the resultant steel material can be provided with characteristics, such as ≥235N/mm2 proof stress YS at ordinary temp., ≤80% YR, and a YS value at 700°C two-thirds the YS value as specification value at ordinary temp. or more, and is applicable to a refractory steel material for construction use.
Inventors:
Atsuhiko Yoshie
Yuzuru Yoshida
Haruo Imai
Chizuiwa Rikio
Yuzuru Yoshida
Haruo Imai
Chizuiwa Rikio
Application Number:
JP15688497A
Publication Date:
January 25, 2006
Filing Date:
June 13, 1997
Export Citation:
Assignee:
Nippon Steel Corporation
International Classes:
C21D8/00; C21D8/02; C22C38/00; C22C38/14; (IPC1-7): C21D8/00; C22C38/00; C22C38/14
Domestic Patent References:
| JP8092640A | ||||
| JP3130319A | ||||
| JP5271753A | ||||
| JP10068044A | ||||
| JP7056044B2 |
Attorney, Agent or Firm:
Hiroaki Tamura
Tomoyuki Yabuki
Tomoyuki Yabuki