US 11,905,992 B2
Crankshaft and method of manufacture
Jianghuai Yang, Rochester Hills, MI (US); James D. Cremonesi, Rochester Hills, MI (US); Paul J. Gelazin, Clarkston, MI (US); Qigui Wang, Rochester Hills, MI (US); and Daniel J. Wilson, Linden, MI (US)
Assigned to GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed by GM Global Technology Operations LLC, Detroit, MI (US)
Filed on Dec. 8, 2020, as Appl. No. 17/114,961.
Application 17/114,961 is a division of application No. 16/056,990, filed on Aug. 7, 2018, granted, now 10,883,154.
Prior Publication US 2021/0087645 A1, Mar. 25, 2021
Int. Cl. F16C 3/06 (2006.01); C21D 9/30 (2006.01); C22C 38/00 (2006.01); C21D 1/18 (2006.01); F16C 3/08 (2006.01); C21D 1/58 (2006.01)
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
OG exemplary drawing
 
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.