| 摘要 |
PURPOSE:To obtain atomized iron powder having low apparent density equal to that of reduced iron powder and excellent formability, by reduction-annealing atomized green iron powder having defined apparent density while increasing sintering-coagulation between particles, and controlling impulsive force to crush and disintegrate sintered cake. CONSTITUTION:Atomized green iron powder having the relationship between its apparent density chi(g/cm<3>) and its particle size di(mum) represented by the arithmetic means of two meshes d1 and d2 of Tyler Standard screen scale which satisfies the formulaIand II (a and b are the constants of particle size with b<=1.5) as for a part having a particle size exceeding 150mum and a part having a particle size below 150mum, respectively, is used. Said green iron powder, directly or after subjected to the treatment to accelerate the coagulation of particles, is reduction-annealed at 800-1,100 deg.C in a reducing decarburizing atmosphere to accomplish sufficient reduction-annealing and sintering-coagulation between particles. The obtained sintered cake is crushed and disintegrated by applying impulsive force below 1X10<5>kgf.m/S<2> to it, so as to obtain iron powder containing more than 80wt% particles having a particle size below 150mum and having apparent density of 2.00-2.60g/cm<3>. |
