CPC F16K 25/005 (2013.01) [B22F 3/12 (2013.01); B22F 3/24 (2013.01); B22F 5/008 (2013.01); F01L 3/02 (2013.01); B22F 2003/248 (2013.01); B22F 2301/10 (2013.01); B22F 2301/15 (2013.01); B22F 2301/35 (2013.01); B22F 2302/40 (2013.01); F01L 2301/00 (2020.05); F01L 2303/00 (2020.05)] | 16 Claims |
1. A powder admixture useful for making a sintered valve seat insert, the powder admixture consisting of a first iron-base powder in an amount of 40-60 wt. %, a second iron-base powder in an amount of 20-40 wt. %, up to 20% Fe powder, up to 3% Cu powder, up to 2% MnS powder, and up to 2% die lubricant, wherein the first iron-base powder has a higher hardness than the second iron-base powder, the first iron-base powder consisting of, in weight percent, 1-2% C, 10-25% Cr, 5-20% Mo, 15-25% Co, 30-60 wt. % Fe, up to 1% Mn, up to 1% Si, up to 5% Ni, up to 5% W, up to 2% V, up to 0.5% B, up to 0.1% P, up to 0.1% S, up to 0.5% N, and up to 5% Nb, and the second iron-base powder consisting of, in weight %, 1-1.5% C, 3-15% Cr, 5-7% Mo, 3-6% W, 1-1.7% V, 60-85% Fe, up to 1% Mn, up to 1% Si, optional Ni, optional Co, and optional Nb.
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