Non-carburized components of track-type machines having a metallurgically bonded coating
Undercarriage assembly components of track-type machines having a metallurgically bonded wear-resistant coating and methods for forming such coated undercarriage assembly components is taught herein. The bodies of the undercarriage assembly components, formed of an iron-based alloy, have a hard metal alloy slurry disposed on a surface or into an undercut or channel and then fused to form a metallurgical bond with the iron-based alloy. The wear-resistant coating comprises a fused, metal alloy comprising at least 60% iron, cobalt, nickel, or alloys thereof. The portion of the outer surface of the undercarriage assembly components having the wear-resistant coating corresponds to a wear surface of the component during operation of the endless track of the track-type vehicle.
1. A track chain bushing comprising:
a bushing comprising non-carburized hardened steel and having at least one wear surface therein, comprising an inner surface having an inner diameter and/or an outer surface having an outer diameter; and
a metallurgically bonded wear-resistant coating disposed on at least a portion of the wear surface around said inner diameter and/or said outer diameter and along at least a portion of a length of the bushing, the wear-resistant coating comprising a fused hard metal alloy comprising at least 60% by weight of iron, cobalt, nickel, or alloys thereof and having a Vickers hardness greater than 950 HV,
wherein the non-carburized hardened steel comprises medium carbon steel.
2. A method for producing the a track chain bushing comprising: a bushing comprising non-carburized hardened steel and having at least one wear surface therein, comprising an inner surface having an inner diameter and/or an outer surface having an outer diameter; and a metallurgically bonded wear-resistant coating disposed on at least a portion of the wear surface around said inner diameter and/or said outer diameter and along at least a portion of a length of the bushing, the wear-resistant coating comprising a fused hard metal alloy comprising at least 60% by weight of iron, cobalt, nickel, or alloys thereof and having a Vickers hardness greater than 950 HV, the method comprising:
coating an exposed area of a non-carburized steel bushing with a slurry comprising the fusible, hard metal alloy with at least 60% by weight of iron, cobalt, nickel, or alloys thereof in the form of a finely divided powder, polyvinyl alcohol, a suspension agent, and a deflocculant;
forming the metallurgical bond between the exposed area and the coating slurry to form the wear-resistant coating;
and hardening the coated bushing.
3. The method according to claim 1 , wherein the hardening composes induction hardening.
4. The method according to claim 1 , wherein the non-carburized steel bushing comprises medium carbon steel.