| 摘要 |
PROBLEM TO BE SOLVED: To provide a piston-ring abrasion-resistant ring that is made of a free-graphite-precipitated iron system sintered material excellent in abrasion resistance and thermal conductivity and moderate in attacking opposite material. SOLUTION: This piston-ring abrasion-resistant ring comprises a free-graphite- precipitated iron system sintered material that has a composition consisting of a free graphite forming component of C in an amount of 0.5 to 5%; basis material forming components of Cr, Mn, S, B, Ni, Cu and Mo in given amounts; hard metal carbide/nitride particles, in an amount of 0.1 to 5%, of carbide, nitride and carbo-nitride of metals of the 4a-, 5a- and 6a-groups in the periodic table and of a mean grain size of 0.1 to 5μm in sectional structure observation under an electron microscope; and a basis material forming component of Fe with inevitable impurities in the remaining amount, and that has a structure wherein the basis material is substantially austenite, the free graphite is substantially absent in the basis material but is present in pores in a precipitation- grown phase, and the hard metal carbide/nitride particles are dispersed in the basis material.
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