IRON-BASED SINTERED ALLOY VALVE SEAT AND MANUFACTURING METHOD THEREOF

Japanese Patent JP2023067801

A

To provide an iron-based sintered alloy valve seat excellent in radial crushing strength.SOLUTION: A functional member-side layer and a support member-side layer are integrally sintered to form a sintered body having a two-layer structure. A mixed powder for the functional member-side layer and a mixed powder for the supporting member-side layer are charged in this order in a mold, pressed to form a compact, and the compact is sintered to form a two-layer structured iron-based sintered alloy valve seat. In the mixed powder for the functional member-side layer, an iron-based powder having a hardness of 170 to 220 HV is used as an iron-based powder for forming a base phase, and the base phase is composed of 150 particles/(30 μm×30 μm) or more of fine carbides with a particle size of 10 μm or less having a Vickers hardness of 550 HV or more, in the base phase, Si-Cr-Mo based Co-based intermetallic compound particles or Si-Cr-Mo-Ni based Co-based intermetallic compound particles having a Vickers hardness of 650 to 1200HV are dispersed in an area ratio of 20 to 40%, and solid lubricant particles are dispersed in an area ratio of 0 to 5%. As a result, a valve seat can have superior radial crushing strength and superior wear resistance. It should be noted that a single-layer structure may be employed in which only the layer on the functional member-side is used.SELECTED DRAWING: None

IKEMI SATOSHI
TAKAGI SEISUKE

JP2022169568A

May 16, 2023

October 24, 2022

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NIPPON PISTON RING CO LTD

C22C38/00; B22F1/00; B22F3/24; B22F5/00; B22F7/00; C22C19/07; C22C33/02; C22C38/58

Kenichiro Ochiai

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