Alloy steel powder for powder metallurgy and method of producing iron-based sintered body

Abstract

Provided is an alloy steel powder for powder metallurgy that is capable of achieving both high strength and high toughness in a sintered body using the same. An alloy steel powder for powder metallurgy of this disclosure comprises a composite alloy steel powder and graphite powder. The composite alloy steel powder has a specific surface area of 0.100 m 2 /g or more and Mo content in a range of 0.2 mass % to 1.5 mass %, and the graphite powder content with respect to 100 mass % of the alloy steel powder for powder metallurgy is in a range of 0.1 mass % to 1.0 mass %.

1 . An alloy steel powder for powder metallurgy comprising: a composite alloy steel powder obtained by adhering an Mo-containing alloy powder to a surface of an iron-based powder; and graphite powder, wherein the composite alloy steel powder has a specific surface area of 0.100 m 2 /g or more and Mo content in a range of 0.2 mass % to 1.5 mass %, and the graphite powder content with respect to 100 mass % of the alloy steel powder for powder metallurgy is in a range of 0.1 mass % to 1.0 mass %. 
     
     
         2 . The alloy steel powder for powder metallurgy according to  claim 1 , further containing Cu powder in a range of 0.5 mass % to 4.0 mass % with respect to 100 mass % of the alloy steel powder for powder metallurgy. 
     
     
         3 . The alloy steel powder for powder metallurgy according to  claim 1 , wherein the iron-based powder contains a reduced iron powder, and a mean particle size of the iron-based powder is 80 μm or less. 
     
     
         4 . The alloy steel powder for powder metallurgy according to  claim 1 , wherein oxygen content of the iron-based powder is 0.3 mass % or less. 
     
     
         5 . A method of producing an iron-based sintered body comprising: adding and mixing a lubricant into the alloy steel powder for powder metallurgy according to  claim 1 ; and performing pressing and sintering to obtain an iron-based sintered body. 
     
     
         6 . The alloy steel powder for powder metallurgy according to  claim 2 , wherein the iron-based powder contains a reduced iron powder, and a mean particle size of the iron-based powder is 80 μm or less. 
     
     
         7 . The alloy steel powder for powder metallurgy according to  claim 2 , wherein oxygen content of the iron-based powder is 0.3 mass % or less. 
     
     
         8 . The alloy steel powder for powder metallurgy according to  claim 3 , wherein oxygen content of the iron-based powder is 0.3 mass % or less. 
     
     
         9 . The alloy steel powder for powder metallurgy according to  claim 6 , wherein oxygen content of the iron-based powder is 0.3 mass % or less. 
     
     
         10 . A method of producing an iron-based sintered body comprising: adding and mixing a lubricant into the alloy steel powder for powder metallurgy according to  claim 2 ; and performing pressing and sintering to obtain an iron-based sintered body. 
     
     
         11 . A method of producing an iron-based sintered body comprising: adding and mixing a lubricant into the alloy steel powder for powder metallurgy according to  claim 3 ; and performing pressing and sintering to obtain an iron-based sintered body. 
     
     
         12 . A method of producing an iron-based sintered body comprising: adding and mixing a lubricant into the alloy steel powder for powder metallurgy according to  claim 4 ; and performing pressing and sintering to obtain an iron-based sintered body. 
     
     
         13 . A method of producing an iron-based sintered body comprising: adding and mixing a lubricant into the alloy steel powder for powder metallurgy according to  claim 6 ; and performing pressing and sintering to obtain an iron-based sintered body. 
     
     
         14 . A method of producing an iron-based sintered body comprising: adding and mixing a lubricant into the alloy steel powder for powder metallurgy according to  claim 7 ; and performing pressing and sintering to obtain an iron-based sintered body. 
     
     
         15 . A method of producing an iron-based sintered body comprising: adding and mixing a lubricant into the alloy steel powder for powder metallurgy according to  claim 8 ; and performing pressing and sintering to obtain an iron-based sintered body. 
     
     
         16 . A method of producing an iron-based sintered body comprising: adding and mixing a lubricant into the alloy steel powder for powder metallurgy according to  claim 9 ; and performing pressing and sintering to obtain an iron-based sintered body.