| 摘要 |
PURPOSE: Fire-resistant steel and a manufacturing method thereof are provided to precipitate a large amount of fine Ti-Mo based carbides or Ti-Mo-V based carbides by heating fire-resistant steel at a high temperature of 600-700°C. CONSTITUTION: Fire-resistant steel comprises C of 0.05-0.13wt.%, Si of 0.01-0.5wt.%, Mn of 0.01-0.5wt.%, Mo of 0.3-1.3wt.%, Ti of 0.03-0.1wt.%, Sol. Al of 0.003-0.07wt.%, N of 0.01wt.% or less, Nb of 0.005-0.05wt.%, V of 0.01-0.05wt.%, Ni of 0.03-0.5wt.%, Cu of 0.03-0.5wt.%, Cr of 0.03-0.5wt.%, Ca of 0.0005-0.005wt.%, Mg of 0.0005-0.005wt.%, and Fe and inevitable impurities of the remaining amount, where yield strengths at 650°C, 700°C, and 25°C satisfy YS_650°C/YS_25°C≥0.5 and YS_700°C/YS_25°C≥0.4. The fire-resistant steel is manufactured by heating a steel material to 1000-1300°C and then cooling the hot rolled steel material(S110,S130). [Reference numerals] (AA) Start; (BB) End; (S110) Heating(1100-1300°C); (S120) Hot rolling(850-1000°C); (S130) Cooling(air-cooling)
|
