US 11,885,289 B2
Components formed with high strength steel
Jonathan Robert Crow, Germantown Hills, IL (US); Lucy Victoria Berg, Germantown Hills, IL (US); Douglas Edward Guyer, II, Bloomington, IL (US); and Michael Alan Pershing, Washington, IL (US)
Assigned to Caterpillar Inc., Peoria, IL (US)
Filed by Caterpillar Inc., Peoria, IL (US)
Filed on Apr. 30, 2021, as Appl. No. 17/246,146.
Prior Publication US 2022/0349370 A1, Nov. 3, 2022
Int. Cl. F02M 61/16 (2006.01); C21D 1/06 (2006.01); C21D 9/00 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/44 (2006.01); C22C 38/46 (2006.01); F02M 61/18 (2006.01)
CPC F02M 61/166 (2013.01) [C21D 1/06 (2013.01); C21D 9/0068 (2013.01); C22C 38/002 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/44 (2013.01); C22C 38/46 (2013.01); F02M 61/18 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A fuel injector, comprising:
a housing;
a nozzle tip seated within the housing, the nozzle tip comprising a body through which fuel is delivered, the body comprising:
a first outer layer, positioned on an external surface of the body, having a hardness of at least about 55 Rockwell Hardness Scale C (HRC) at or adjacent the external surface, the first outer layer also having a compressive stress, the first outer layer having a vanadium content of at least about 0.1% by weight, and a first carbon content in a first range of 0.7% by weight to 1.6% by weight;
a second outer layer having a hardness of at least about 55 Rockwell Hardness Scale C (HRC) and compressive stress, the second outer layer having a vanadium content of at least about 0.1% by weight, a second carbon content in a second range of 0.7% by weight to 1.6% by weight, and positioned on an internal surface of the body,
a core layer encased by the first outer layer and the second outer layer, the core layer having a third carbon content in a third range of 0.17% by weight to 0.5% by weight, a hardness less than about 55 HRC, and tensile stress, wherein the third range does not overlap the first range or the second range to produce a drop-off in carbon content from the first outer layer to the core layer; and
wherein the first outer layer is at least 250 micrometers (μm) in thickness, and
wherein the first outer layer maintains a first hardness of at least 59 HRC at a depth of at least 250 μm from the external surface after the fuel injector is exposed to a temperature of at least about 300° C. in an operating environment for at least about 3 hours.