Components formed with high strength steel

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.