The materials used for each component of the Nabla railway fastener system are directly related to the performance, durability and safety of the system. Different components are adapted to specific materials according to their functional requirements.
Metallic materials
Elastic springs
Elastic springs are crucial in the Nabla system, and are often made of spring steel materials such as 60Si2MnA and 60Si2CrA. Taking 60Si2MnA as an example, it contains about 0.6% carbon and contains alloy elements such as silicon (Si) and manganese (Mn).
Bolts and nuts
Bolts and nuts are responsible for connecting various components. Common materials include Q235 (corresponding to performance level 4.6) and No. 35 steel (corresponding to performance level 5.0).
Connecting steel plates
Connecting steel plates need to have high strength and toughness, and low-alloy high-strength structural steels such as Q345 are generally used. Q345 contains alloy elements such as niobium (Nb), vanadium (V), and titanium (Ti). These elements improve the strength, toughness, and fatigue resistance of steel by refining grains, so that the connecting steel plate can firmly connect various components and resist the complex stress generated by train operation.
Engineering plastic material
Plastic substrate (under-rail insulation pad)
The plastic substrate is mainly made of reinforced nylon 66 (PA66). PA66 itself has good mechanical properties, wear resistance, self-lubricating and insulation properties.
Rubber material
Rubber pad
Rubber pads are usually made of natural rubber or synthetic rubber, such as chloroprene rubber, styrene-butadiene rubber, etc. Natural rubber has excellent elasticity, flexibility, and wear resistance, and can effectively absorb the vibration and noise generated by train operation, reducing the impact on sleepers and roadbeds. Neoprene has outstanding performance in weather resistance, oil resistance and flame retardancy, and can adapt to a variety of complex environments; styrene-butadiene rubber has a lower cost and better comprehensive performance, and can control costs while ensuring a certain vibration reduction and noise reduction effect.