Why is the brake disc of my newly purchased car rusting?

[StIan]

It mainly depends on the material of the brake disc. Although the braking effect is good, the carbon content is relatively high, and the surface is not protected against rust, so rust is inevitable. Here is some relevant information: Brake disc: It is a round disc that also rotates when the car is moving. The brake caliper clamps the brake disc to generate braking force. When you press the brake, it clamps the brake disc to slow down or stop the car. The braking effect of the brake disc is good, and it is easier to maintain than drum brakes. Classification: Brakes include disc brakes, drum brakes, and air brakes. Many older cars have disc brakes in the front and drum brakes in the rear. Many newer cars have disc brakes on both the front and rear. Because disc brakes dissipate heat better than drum brakes, they are less prone to thermal fade during high-speed braking, resulting in better high-speed braking performance.