PURE IRON POWDER FOR POWDER METALLURGY PRODUCED BY ATOMIZATION METHOD USING WATER AND ITS PRODUCTION

摘要

PURPOSE: To produce the iron powder for iron metallurgy which decreases the width of fluctuations in dimensional change at the time of sintering by pulverizing molten iron of a low Si content and low Mn content by a water atomization method, then drying the powder in an oxygen-contg. gaseous nitrogen atmosphere and, in succession, reducing the powder in a reducing gaseous atmosphere. ;CONSTITUTION: The molten iron of the compsn. contg., by weight % 0.008 to 0.025% Si, 0.01 to 0.30% Mn and 0.25% O₂ and consisting of the balance Fe is pulverized by the water atomization method to produce the iron powder as the raw material for iron metallurgy. This powder is dried in the atmosphere having 2.5 to 7.5vol.% oxygen concn. and consisting the balance the gaseous nitrogen to decrease the width in the fluctuations in the ratio of the Si content constituting the oxide in the Si contained in the iron powder to ≤50%. The powder is then subjected to the reduction under heating in the reducing gaseous atmosphere of hydrogen, etc., by which the iron powder for the iron metallurgy having the decreased width in the fluctuations of the dimensional changes of the sintering member at the time of sintering is produced.;COPYRIGHT: (C)1993,JPO&Japio