What are the differences in durability between cold-rolled steel and aluminum alloy?

Cold-rolled steel and aluminum alloy have the following differences in durability:

Corrosion resistance
Cold-rolled steel: It does not have natural anti-corrosion properties by itself, but after surface treatments such as galvanizing and coating with aluminum-zinc alloy, its corrosion resistance will be significantly enhanced. For instance, the aluminum-zinc alloy coating on cold-rolled steel plates makes their corrosion resistance in humid environments far superior to that of ordinary galvanized steel plates.
Aluminum alloy: It has excellent corrosion resistance. A dense oxide film will naturally form on its surface, effectively preventing further corrosion and performing exceptionally well in humid environments.

Strength and stiffness
Cold-rolled steel: It features high strength and rigidity, a high strength-to-weight ratio, and is capable of withstanding significant loads, making it suitable for heavy-duty shelving systems.
Aluminum alloy: Its strength is relatively lower than that of cold-rolled steel. However, after heat treatment and strengthening (such as 6-series aluminum alloy), it can also meet certain strength and rigidity requirements and is suitable for external covering parts and other components.

Impact resistance
Cold-rolled steel: It has relatively good impact resistance and can withstand considerable impact forces.
Aluminum alloy: When subjected to impact, it can absorb a large amount of energy and has certain energy absorption capacity and shock wave attenuation capacity, demonstrating excellent impact resistance in applications such as automotive bodies.

Dimensional stability
Cold-rolled steel: Dimensional stability, not affected by humidity, will not expand or contract due to humidity changes, nor will it crack or warp over time.
Aluminum alloy: Its dimensional stability is relatively weak and it may be affected by temperature changes.

Overall durability performance
Cold-rolled steel: It is highly durable and has a long service life. It performs well in dry and well-ventilated environments. After appropriate protective treatment, it can be used for a long time in various environments.
Aluminum alloy: It has good durability, especially excelling in corrosion resistance and impact resistance, and is suitable for occasions with high requirements for weight and aesthetics.

To sum up, cold-rolled steel and aluminum alloy each have their own advantages in terms of durability. The specific choice should be determined based on the actual application scenarios and requirements.