Caterpillar Inc.

Michael Alan Pershing

Scott A Johnston

Robert Jason Pickerill

Curtis A Henning

Timothy F Nusz

Chetan Vilas Dahiwal

Swetha Suresh

Jonathan Robert Crow

Lucy Victoria Berg

Douglas Edward Guyer, Ii

Benjamin J Bargfrede

Todd M Blindt

Roller cone drill bits and methods of increasing the wear resistance of a roller cone drill bit are disclosed. The roller cone drill bit includes a plurality of rolling elements within a bearing assembly of a cone. Each rolling element of the plurality of rolling elements may have a surface hardness of HRC 59-63, a hardened depth that is 0.5 mm to 3.0 mm deep, and may be derived from a low carbon bearing steel material. The hardened depth is measured from the surface of each rolling element and the low carbon bearing steel material has, by weight percent, from 0.12% to 0.25% carbon.

Bearing materials for tricone bit rolling elements

A carburized steel component, comprising a steel base including, by weight percent, from 0.08% to 0.35% carbon, 0.5% to 1.3% manganese, 0% to 0.35% silicon, 0.2% to 2.0% chromium, 0% to 4% nickel, 0% to 0.50% molybdenum, 0% to 0.06% niobium, and a remaining weight percent of iron, and a carburized layer of above 0.35% by weight carbon from a surface of the carburized layer to a carburized layer depth, wherein the carburized layer depth is from 0.5 mm to 3.0 mm, wherein the carburized layer comprises a microstructure including martensite, retained austenite, carbide, and less than 2% by volume non-martensitic transformation products (NMTP), and wherein the carburized layer includes a prior austenite average grain size of 3.0-8.0 microns from the surface to a depth of at least 0.2 mm.

Carburized steel component and carburization process

An example component of a machine includes a core layer and an outer layer encasing the core layer. The outer layer has a greater carbon concentration and hardness than the core layer. The outer layer may also be compressively stressed, while the core layer may have tensile stress. The stress and/or hardness profile of the component may enhance its resistance to cracking, particularly in applications where the component is impacted by other object and/or operates at elevated temperatures. The component, such as parts of a fuel injector, may be formed by rough forming the component, carburizing the component, quenching the component, subzero processing the component, and then performing a tempering process. The components may have relatively sharp transition from the high carbon outer layer to the lower carbon core layer. Additionally, the components have a relatively high tempering resistance when used in relatively high temperature environments.

Components formed with high strength steel

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Washington, IL, United States of America

Michael Alan Pershing