Patent number: 10273838
Abstract: Provided is a valve seat insert made of an iron-base sintered alloy, in which a base matrix part that includes a base matrix phase and hard particles, has a base matrix part composition containing, in % by mass, 0.5%-2.0% of carbon and 10%-70% in total of one kind or two or more kinds selected from nickel, cobalt, chromium, molybdenum, vanadium, tungsten, manganese, silicon and sulfur, with the balance being iron and unavoidable impurities, and Co-base hard particles having a composition containing, 1.0% or less of C, 25%-50% of Mo, 5%-15% of Cr, Si as an impurity in a content adjusted to be 0.3% or less, with the balance being Co, and having a Vickers hardness of 500 to 1,500 HV, are dispersed as hard particles in the base matrix phase in an amount of 10%-60% by mass with respect to the total amount of the valve seat insert.
Type:
Grant
Filed:
December 21, 2016
Date of Patent:
April 30, 2019
Assignees:
NIPPON PISTON RING CO., LTD., HONDA MOTOR CO., LTD., SANYO SPECIAL STEEL CO., LTD.
Inventors:
Satoshi Ikemi, Hiroshi Oshige, Seisuke Takaki, Tomoki Okita, Keisuke Ishii, Toshiyuki Sawada, Hiroyuki Hasegawa