Abstract: An example bushing of a hydraulic hammer tool includes an outer region and an inner region. The inner region has a relatively greater hardness than the outer region. The inner region may also be compressively stressed, while the outer region may have tensile stress. The stress and/or hardness profile of the bushing may enhance its resistance to wear and galling defects when a hammer of the hydraulic hammer tool is held in alignment by the bushing. The outer region of the bushing may be relatively soft, resulting in the bushing having a relatively high level of toughness. The bushing may be formed using medium to high carbon steel by rough forming the bushing, hardening the bushing, tempering the bushing, and induction softening the outer region of the bushing.

Abstract: An example bushing has three portions along its radial direction including an inner portion most proximal to a central hole of the bushing, an outer portion most distal from the center hole, and a core portion between the inner portion and the outer portion. The core portion has a hardness that is less than the hardness of the inner portion or the outer portion of the bushing. The bushing may be formed using high carbon steel, which in some cases may be spheroidal cementite crystal structure. A rough bushing may be formed using the high carbon steel, followed by a direct hardening process, and an induction hardening process on the inner surface most proximal to the central hole of the bushing. The induction hardening on the inner surface may harden the outer portion while tempering the core portion of the bushing.

Abstract: A steel track chain component, such as a track bushing, may be formed with a carburized portion, a hardface portion, and a core portion. The core portion may be softer than the carburized portion, which in turn, may be softer than the hardface portion. This configuration of the various portions of the component may allow for relatively high wear resistance of the component, as well as toughness. The core portion may be mostly ferrite crystal structure, while the carburized portion and the hardface portions may include martensitic and/or austenitic crystal structure. The carburized portion may be formed by carburizing the track chain component in a heated and carbon rich environment. The hardface portion may be formed by welding a hardface alloy over at least a portion of the carburized portion.

Abstract: An example bushing of a hydraulic hammer tool includes a bulk region and an inner region. The inner region has a relatively greater hardness than the bulk region. The inner region may also be compressively stressed, while the bulk region may have tensile stress. The stress and/or hardness profile of the bushing may enhance its resistance to wear and galling defects when a hammer of the hydraulic hammer tool is held in alignment by the bushing. The bulk region of the bushing may be relatively soft, resulting in the bushing having a relatively high level of toughness. The bushing may be formed using medium to high carbon steel by rough forming the bushing, hardening the bushing, tempering the bushing, induction hardening the inner region of the bushing, and then quenching the inner region.

Abstract: A steel track chain component, such as a track bushing, may be formed with a carburized portion, a hardface portion, and a core portion. The core portion may be softer than the carburized portion, which in turn, may be softer than the hardface portion. This configuration of the various portions of the component may allow for relatively high wear resistance of the component, as well as toughness. The core portion may be mostly ferrite crystal structure, while the carburized portion and the hardface portions may include martensitic and/or austenitic crystal structure. The carburized portion may be formed by carburizing the track chain component in a heated and carbon rich environment. The hardface portion may be formed by welding a hardface alloy over at least a portion of the carburized portion.

Abstract: An example bushing has three portions along its radial direction including an inner portion most proximal to a central hole of the bushing, an outer portion most distal from the center hole, and a core portion between the inner portion and the outer portion. The core portion has a hardness that is less than the hardness of the inner portion or the outer portion of the bushing. The bushing may be formed using high carbon steel, which in some cases may be spheroidal cementite crystal structure. A rough bushing may be formed using the high carbon steel, followed by a direct hardening process, and an induction hardening process on the inner surface most proximal to the central hole of the bushing. The induction hardening on the inner surface may harden the outer portion while tempering the core portion of the bushing.