| 摘要 |
PURPOSE:To obtain steel material having improved strength and toughness, by limiting quantity of B in maraging steel having a prescribed compsn., adjusting the other components suitably and soln. heat treating the steel under a specified temp. range, thence age treating it. CONSTITUTION:The compsn. is composed of <=0.05wt% C, <=0.2% Si, <=0.1% Mn, <=0.05% P, <=0.05% S, 16-21% Ni, >9.5%-<15% Co, 4-6.5% Mo, 0.2-1.6% Ti, <=0.15% Al, 0.0005-0.0020% B and the balance Fe with inevitable impurity. The steel is heated to 780-850 deg.C and soln. heat treated. Thereafter, aging treatment is applied by conventional method. By maraging steel having the compsn., since strength and toughness can be improved by simple heat treatment, the steel is useful for use of steel material such as thick and special shapes. |
