Sintered sliding member and method for producing same

A sintered sliding member comprising;

• a lubrication phase;
• a solid lubricant;
• and
• a matrix, wherein
• the lubrication phase and the solid lubricant are dispersed in the matrix,
• a composition of a main phase formed of the matrix and the lubrication phase is composed of a composition containing, by mass %, Cr:
• 18% to 35%, Mo:
• 0.3% to 15%, Ni:
• 0% to 30%, Si:
• 0.5% to 6%, S:
• 0.2% to 4.0%, P:
• 0% to 1.2%, B:
• 0% to 0.8%, and a Fe balance containing inevitable impurities,
• the matrix is a Fe—Cr—Mo—Si-based matrix or a Fe—Cr—Mo—Ni—Si-based matrix,
• the lubrication phase contains chromium sulfide,
• a porosity of an entire sliding member is 2.0% or less, the solid lubricant is composed of one or two or more of CaF2, talc, and BN, and
• the lubricant is contained in an amount of 1 mass % or less with respect to the main phase.

A method for producing a sintered sliding member that has a structure in which a lubrication phase is dispersed in a matrix,

• wherein an entire composition of the sliding member is composed containing, by mass %, a composition of Cr:
• 18% to 35%, Mo:
• 0.3% to 15%, Ni:
• 0% to 30%, Si:
• 0.5% to 6%, S:
• 0.2% to 4.0%, P:
• 0% to 1.2%, B:
• 0% to 0.8%, and a Fe balance containing inevitable impurities, the matrix is a Fe—Cr—Mo—Si-based matrix or a Fe—Cr—Mo—Ni—Si-based matrix, the lubrication phase contains chromium sulfide, and a porosity of an entire sliding member is 2.0% or less, the method comprising steps of:
• mixing a FeCr-based or FeCrNi-based alloy powder with a MoS2 powder to obtain a mixed powder;
• press-forming the mixed powder to produce a green compact;
• and
• sintering the green compact at 1100° C. or higher in a vacuum atmosphere.

A method for producing a sintered sliding member that has a structure in which a lubrication phase and a solid lubricant are dispersed in a matrix, in which a composition of a main phase formed of the matrix and the lubrication phase is composed of a composition containing, by mass %, Cr:

• 18% to 35%, Mo:
• 0.3% to 15%, Ni:
• 0% to 30%, Si:
• 0.5% to 6%, S:
• 0.2% to 4.0%, P:
• 0% to 1.2%, B:
• 0% to 0.8%, and a Fe balance containing inevitable impurities, the matrix is a Fe—Cr—Mo—Si-based matrix or a Fe—Cr—Mo—Ni—Si-based matrix, the lubrication phase contains chromium sulfide, a porosity of an entire sliding member is 2.0% or less, the solid lubricant is composed of one or two or more of CaF2, talc, and BN, and the lubricant is contained in an amount of 1 mass % or less with respect to the main phase, the method comprising the steps of:
• mixing a FeCr-based or FeCrNi-based alloy powder, a MoS2 powder, and a solid lubricant powder with each other to obtain a mixed powder;
• press-forming the mixed powder to produce a green compact;
• and
• sintering the green compact at 1100° C. or higher in a vacuum atmosphere.