Corrosion resistant cermet wear parts
AssigneeKennametal Inc.
InventorsWilliam M. Stoll, James P. Materkowski, Ted R. Massa
Life of this patent
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Abstract
A corrosion resistant cermet comprises a ceramic component (e.g., WC) and a binder alloy comprised of a major component (e.g., one or more of iron, nickel, cobalt, their mixtures, and their alloys) and at least one additive component (e.g., one or more of ruthenium, rhodium, palladium, osmium, iridium, and platinum). Plungers for hyper compressors used in the corrosive environments generated during the manufacture of low density polyethylene (LDPE) or ethylene copolymers are an example of the use of the corrosion resistant cermet.
Claims35
A plunger for use in a hyper compressor comprising:
- (a) an elongated body;
- (b) a first end;
- (c) a second end, wherein the second end further comprises an attachment that facilitates the reciprocation of the plunger within a portion of the a hyper compressor;
- and
- (d) a surface extending between the first end and the second end, at least a portion the plunger being comprised of a corrosion and wear resistant cermet composition comprising:
- (i) at least one ceramic component, wherein the at least one ceramic component comprises at least one of boride(s), carbide(s), nitride(s), oxide(s), silicide(s), their mixtures, their solutions, and combinations thereof;
- and
- (ii) between about 6-19% by weight binder alloy consisting essentially of a major component and between about 26-60% by weight of an additive component, wherein the major component consists of one or more of iron, nickel, cobalt, their mixtures, and their alloys;
- the additive component consists of at least one of ruthenium, rhodium, palladium, osmium, iridium, platinum, their mixtures and their alloys;
- and the interaction of the major component and the additive component imparts corrosion resistance to the plunger.
A plunger for use in a hyper compressor comprising:
- (a) an elongated body;
- (b) a first end;
- (c) a second end, wherein the second end further comprises an attachment that facilitates the reciprocation of the plunger within a portion of the a hyper compressor;
- and
- (d) a surface extending between the first end and the second end, at least a portion of the plunger being comprised of a corrosion and wear resistant cermet composition comprising:
- (i) at least tungsten carbide;
- and
- (ii) between about 6-19% by weight binder alloy consisting essentially of cobalt and between about 26-60% by weight ruthenium, wherein the interaction of cobalt and ruthenium imparts corrosion resistance to the plunger.
A plunger for use in a hyper compressor comprising:
- (a) an elongated body;
- (b) a first end;
- (c) a second end;
- and
- (d) a surface extending between the first end and the second end, the plunger being comprised of a corrosion and wear resistant cermet composition comprising:
- (i) at least tungsten carbide and
- (ii) between about 6-19% by weight binder alloy consisting essentially of cobalt or cobalt alloys and between about 26-60% by weight ruthenium, wherein the interaction of the cobalt or cobalt alloys and the ruthenium imparts corrosion resistance to the plunger.
Dependencies are inferred from the claim text.