Patent ID: 11885289
Assignee: CATERPILLAR INC.
Field: Materials, metallurgy (Chemistry)
Classification: CPC C  F | IPC C  F

Claim 4:
5. The fuel injector of claim 1, wherein the fuel injector further comprises a fuel injector nozzle valve that contacts the internal surface to control delivery of fuel through the fuel injector, the fuel injector nozzle valve comprising:
an outer layer having a hardness of at least about 55 Rockwell Hardness Scale C (HRC) and compressive stress, the outer layer having a vanadium content of at least about 0.1% by weight and positioned on an external surface of the fuel injector nozzle valve; and
a core layer encased by the outer layer, the core layer having a hardness less than about 55 HRC and tensile stress; and
wherein the outer layer is at least 250 micrometers (μm) in thickness, and
wherein the outer layer maintains a first hardness of at least 59 HRC at a depth of at least 250 μm after the fuel injector nozzle valve is exposed to a temperature of at least about 300° C. in an operating environment for at least about 3 hours.