Sintered material for valve guides and production method therefor

摘要

A sintered material for valve guides consists of, by mass %, 1.3 to 3% of C, 1 to 4% of Cu, 0.01 to 0.08% of P, 0.05 to 0.5% of Sn, and the balance of Fe and inevitable impurities. The sintered material exhibits a metallic structure made of pores and a matrix. The matrix is a mixed structure of a pearlite phase, a ferrite phase, an iron-phosphorus-carbon compound phase, and at least one of a copper-tin alloy phase and a combination of a copper phase and a copper-tin alloy phase. A part of the pores includes graphite that is dispersed therein. The iron-phosphorus-carbon compound phase is dispersed at 3 to 25% by area ratio, and the copper-tin alloy phase and the combination of the copper phase and the copper-tin alloy phase are dispersed at 0.5 to 3.5% by area ratio, with respect to a cross section of the metallic structure, respectively.

主权项

1. A sintered material for valve guides, consisting of, by mass %:
1.3 to 3% of C, 1 to less than 3.5% of Cu, 0.01 to 0.08% of P, 0.05 to 0.5% of Sn, and the balance of Fe and inevitable impurities,
wherein:the sintered material exhibits a metallic structure made of pores and a matrix, the matrix being a mixed structure of a pearlite phase, a ferrite phase, an iron-phosphorus-carbon compound phase, and at least one of a copper-tin alloy phase and a combination of a copper phase and a copper-tin alloy phase, and a part of the pores including graphite that is dispersed therein, andthe iron-phosphorus-carbon compound phase is dispersed at 3to 25% by area ratio, and the copper-tin alloy phase and the combination of the copper phase and the copper-tin alloy phase are dispersed at 0.5 to 3.5% by area ratio, with respect to a cross section of the metallic structure, respectively.