CPC F16C 3/06 (2013.01) [C21D 9/30 (2013.01); C22C 38/00 (2013.01); C21D 1/18 (2013.01); C21D 1/58 (2013.01); C21D 2211/005 (2013.01); C21D 2211/008 (2013.01); F16C 3/08 (2013.01); F16C 2202/04 (2013.01); F16C 2204/62 (2013.01); F16C 2204/64 (2013.01); F16C 2223/10 (2013.01); Y10T 29/49286 (2015.01)] | 18 Claims |
1. A crankshaft for an internal combustion engine, the crankshaft comprising:
a plurality of journals each comprising a surface and a hardened case, and wherein the crankshaft is made of a steel comprising between 0.3 wt % and 0.77 wt % Carbon and the hardened case has a first microstructure comprising ferrite and martensite having a residual stress between 400 MPa and 550 MPa, and wherein the plurality of journals have been heated to an intercritical temperature of between 724° C. and 822° C.
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