Engine Crankshaft Processing

The processing of an engine crankshaft typically follows a complete chain of processes: forging → machining → heat treatment → finishing → inspection. Each step complements the others to ensure strength, wear resistance, and service life.

1. Forging Process: Die forging or open die forging is used to form the crankshaft blank, improving its structural density and mechanical properties.

2. Turning: Rough turning is used to remove excess stock, and the main journal, connecting rod neck, and end faces are turned to ensure dimensions close to design requirements.

3. Milling: Machining the crankshaft and balance weights, and finishing complex curved surfaces.

4. Heat Treatment Process: Processes such as quenching and tempering, high-frequency hardening or induction hardening, and localized nitriding are used to improve surface hardness and fatigue strength.

5. Grinding: Fine grinding of the main journal and connecting rod necks to achieve high-precision dimensional, geometric, and roughness requirements.

6. Polishing/Superfinishing: Polishing or rolling is used to strengthen the neck surface, reduce roughness, and improve wear resistance.

7. Dynamic Balancing
A dynamic balancing machine is used to check and correct imbalances to ensure stable crankshaft rotation.

8. Flaw Detection
Magnetic particle or ultrasonic flaw detection is used to eliminate internal cracks and defects.