Delong rear

Definition

Spheroidal graphite cast iron (commonly known as ductile iron) brake drums are automotive brake components made from spheroidal graphite cast iron material. Spheroidal graphite cast iron is a type of cast iron with a unique graphite morphology, where the graphite appears in a worm-like shape.

Characteristics

Excellent mechanical properties

Ductile iron brake drums have high strength and toughness. Their tensile strength is significantly higher than that of ordinary gray cast iron, generally reaching 300 - 500 MPa or even higher. This allows the brake drums to withstand the immense pressure and impact forces during braking without easily deforming or breaking.

Its fatigue strength is also good, able to withstand the alternating stresses generated by frequent braking operations. Over long-term use, it can maintain good structural integrity, extending the lifespan of the brake drums.

Good thermal conductivity

The thermal conductivity of ductile iron is slightly higher than that of gray cast iron, allowing for quicker dissipation of heat generated during braking. This helps prevent the brake drums from overheating locally during braking, which can lead to decreased braking performance, such as reduced braking efficiency and the occurrence of thermal cracks.

Excellent shock absorption performance

Due to its unique graphite morphology, ductile iron brake drums exhibit good shock absorption performance during braking. They can effectively absorb and dampen vibrations and noise generated during braking, improving passenger comfort while also reducing damage to other vehicle components caused by vibrations.

Application of ductile iron brake drums in the automotive industry

Currently, ductile iron brake drums are used in certain vehicles such as medium and heavy-duty trucks and large buses. These vehicles, due to their heavy loads and high speeds, have high performance requirements for brake drums. Ductile iron brake drums can adequately meet their demands for braking performance and reliability.
There are also experimental applications of ductile iron brake drums in some high-performance passenger cars. As the automotive industry continues to raise demands for braking performance and vehicle lightweighting and environmental friendliness, the application range of ductile iron brake drums is gradually expanding.

Advantages

Improved braking safety

During vehicle braking, the performance of the brake drums directly affects the vehicle's braking distance and stability. The high mechanical properties and good thermal conductivity of ductile iron brake drums ensure that they can operate stably under high-speed, heavy-load braking conditions, effectively shortening braking distances and reducing the occurrence of traffic accidents.

Meets environmental protection requirements

Due to their good performance, ductile iron brake drums can reduce waste generated from frequent replacements. Moreover, their stable braking performance helps improve vehicle fuel economy and reduce exhaust emissions. For example, applying ductile iron brake drums in urban public transport vehicles can reduce energy consumption and emissions to some extent by decreasing braking losses.

Extended vehicle maintenance cycles

The long lifespan characteristics of ductile iron brake drums mean that vehicles do not need to frequently replace brake drums during use. This not only lowers maintenance costs but also reduces vehicle downtime caused by repairs and part replacements, improving operational efficiency.