Here's why:
* Strength and Durability: Crankshafts are subjected to immense forces, both rotational and torsional. Steel, particularly alloy steel, provides the necessary strength and durability to withstand these stresses.
* Wear Resistance: Crankshafts experience friction from the bearings and connecting rods. Alloy steel, with its increased hardness and wear resistance, helps to minimize wear and tear.
* Fatigue Resistance: Crankshafts undergo repeated stress cycles. Alloy steel has better fatigue resistance than regular steel, reducing the risk of failure over time.
* Cost-Effectiveness: While other materials, like titanium, could be used, they are significantly more expensive. Steel provides a balance between performance and cost for the majority of applications.
Common Types of Steel Used:
* 4140 Steel: A common choice for crankshafts, known for its strength, toughness, and good wear resistance.
* 4340 Steel: Offers even better strength and fatigue resistance than 4140 steel, making it suitable for high-performance applications.
* 8620 Steel: Provides good wear resistance and machinability, often used for less demanding applications.
The specific type of steel used will depend on the engine's design, operating conditions, and performance requirements.
