Patent ID: 8074355
Filing Date: 2011-12-13
Classification: B21D,B21K,F16C,Y10T

Abstract:
1. A method for manufacturing a connecting rod for an internal combustion engine, the connecting rod having a first end for interaction with rolling element bearings allowing connection with a crankshaft, the first end including a large end hole, and a second end for interaction with rolling element bearings allowing connection with a piston pin, the method comprising: forging a rough connecting rod from high carbon steel, the high carbon steel having a carbon constituency in the range of 0.80% to 1.2% by weight; normalizing the connecting rod to provide strength and toughness properties to a core of the connecting rod for functional operation, the step of normalizing comprising: heating the rough connecting rod to a austenite transformation temperature, holding the rough connecting rod at or above the austenite transformation temperature until the rough connecting rod is austenitized, and air cooling the rough connecting rod, wherein the step of normalizing forms, in the rough connecting rod, a BCC structure having two structure phases composed of alternating plates of alpha-ferrite and iron carbide; machining the rough connecting rod into near-final form; selectively induction hardening the first end and the second end of the connecting rod, the step of selectively induction hardening further comprising energizing an electrical coil; bringing the coil into functional proximity with the first end of the connecting rod, heating the first end of the connecting rod at or above the austenite transformation temperature, quenching the first end to form a martensite structure in the first end,