Reduced iron powder and method for preparing same and bearing

Abstract

Reduced iron powder that has fewer coarse inclusions, has excellent formability, has high porosity after sintering, has excellent reactivity per unit mass, and can be effectively used as reaction material even to the particle inside is provided. Reduced iron powder has an apparent density of 1.00 Mg/m 3 to 1.40 Mg/m 3 .

1 . Reduced iron powder having an apparent density of 1.00 Mg/m 3  to 1.40 Mg/m 3 . 
     
     
         2 . The reduced iron powder according to  claim 1 , having an amount of oxygen of 0.38 mass % or less. 
     
     
         3 . The reduced iron powder according to  claim 1 , having a specific surface area of 0.20 m 2 /g or more. 
     
     
         4 . A method for preparing reduced iron powder, for use in preparing the reduced iron powder according to  claim 1 , comprising:
 agglomerating precursor iron oxide powder whose mean particle size measured by a laser diffraction method is 3.0 μm or less to obtain iron oxide powder; and   thereafter reducing the iron oxide powder at 800° C. to 1000° C. with hydrogen to obtain the reduced iron powder.   
     
     
         5 . The method for preparing reduced iron powder according to  claim 4 , comprising
 classifying and selecting the iron oxide powder so that its mean particle size measured by the laser diffraction method is 50 μm to 200 μm, before the reduction of the iron oxide powder.   
     
     
         6 . The method for preparing reduced iron powder according to  claim 4 ,
 wherein the iron oxide powder has an iron content of 68.8 mass % or more.   
     
     
         7 . A bearing produced from the reduced iron powder according to  claim 1  as a raw material. 
     
     
         8 . A bearing produced from the reduced iron powder according to  claim 2  as a raw material. 
     
     
         9 . A bearing produced from the reduced iron powder according to  claim 3  as a raw material.