公开(公告)号：WO2021067041A1

公开(公告)日：2021-04-08

申请号：PCT/US2020/051188

申请日：2020-09-17

Applicant: CATERPILLAR INC.

Inventor： RATHOD, Chandrasen R. ,  RECKER, Roger L. ,  PICKERILL, Robert J. ,  KEELE, Scott E. ,  WEAVER, Douglas T. ,  SORDELET, Daniel J.

IPC: B62D55/21

Abstract: A steel track chain component (162, 164, 166, 168, 202, 204), such as a track bushing (204), may be formed with a carburized portion (404), a hardface portion (412), and a core portion (410). The core portion (410) may be softer than the carburized portion (404), which in turn, may be softer than the hardface portion (412). This configuration of the various portions of the component (162, 164, 166, 168, 202, 204) may allow for relatively high wear resistance of the component (162, 164, 166, 168, 202, 204), as well as toughness. The core portion (410) may be mostly ferrite crystal structure, while the carburized portion (412) and the hardface portion (412) may include martensitic and/or austenitic crystal structure. The carburized portion (412) may be formed by carburizing the track chain component (162, 164, 166, 168, 202, 204) in a heated and carbon rich environment. The hardface portion (412) may be formed by welding a hardface alloy over at least a portion of the carburized portion (404).

公开(公告)号：WO2021061313A1

公开(公告)日：2021-04-01

申请号：PCT/US2020/047292

申请日：2020-08-21

Applicant: CATERPILLAR INC.

Inventor： RATHOD, Chandrasen Rameshlal ,  RECKER, Roger Lee ,  PICKERILL, Robert Jason ,  KEELE, Scott E. ,  KISER, Matthew Thomas

IPC: C21D1/06 ,  C21D1/18 ,  C21D1/42 ,  C21D9/00 ,  C21D1/10

Abstract: An example bushing (204) has three portions along its radial direction including an inner portion (410) most proximal to a central hole of the bushing (204), an outer portion (404) most distal from the center hole, and a core portion (406) between the inner portion (410) and the outer portion (404). The core portion (406) has a hardness that is less than the hardness of the inner portion (410) or the outer portion (404) of the bushing (204). The bushing (204) 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 (412) most proximal to the central hole of the bushing (204). The induction hardening on the inner surface (412) may harden the outer portion (404) while tempering the core portion (406) of the bushing (204).