How to deal with car brake discs: anti-rust paint or rust?


The car brake disc rust is very normal, because the brake disc is “iron products”; the brake disc of the disc brake system is exposed to the air for a long time, and the installation bit is lower is the most easily splashed to the water. The oxygen in the air plus water and adds iron products, which is almost for rusty “perfect combination”, below to understand the characteristics of the brake disc.


Brake disc and gray cast iron


The brake drums used by the disc brakes and drum brakes are all gray cast iron, but the national standard standard of the disc is HT250, and the drum brake can be adjusted between HT200 ~ 300. The ingredients of the gray cast iron include iron, carbon, silicon, manganese, sulfur, phosphorus, etc., wherein the sheet graphite has a severe cutting of the base of the cast iron, and the stress concentration is easily reduced in the graphite tip to reduce the phenomenon of tensile strength. However, the compressive strength is not inferior to steel, so it is still possible to use a brake disc that is sandwiched in a disc brake.

Brake disc mechanical performance standard


Tensile strength ≥206MPa

Bending strength ≥1000MPa

Deflection ≥ 5.1mm

Hardness between 187 ~ 241HBS

Brake discs of the car need to meet these standards to load the use, try to choose the brake discs produced in the middle of the manufacturer when choosing the brake disc. Because the brake disc serves as the casting member is relatively high, there are high temperatures or high temperatures are not suitable for production brake discs.

Brake tray rusty processing method


After understanding the brake disc as a cast iron product, it should be easily accepted for rust, because it is not rusty. Brake disc rust often brings abnormal noise, and the start of the brakes after severe rust, it will feel that it is not linear or even frustrated; but this situation does not affect driving safety, because the brake discs are only need to step on a few foot brakes Easy to polish. The disc brake is to apply a hydraulic pressure using the brake head pump. The brake disc “hug” brake disc on the pump is pushed by the extrusion of the brake oil, and the frictional force of the two is decelerated.

The brake disc is a structure that is rigidly fixed with the bearing, and the hub is rotated at the hub; the deceleration of the brake disc is equal to the wheel deceleration. For the reduction of various types of household scheduling vehicles in the total quality of 1 to 3 tons, the pressure requirements for the brake pump for the brake pads will be very high, and high pressure is equal to the friction between the brake disc and the brake pad. Force, in this high-strength friction, it will inevitably beaten rust on the brake disc.

In summary, the brake disc rust is very easy to handle, but some “forced disorder” always does not want to have rust on the brake disc, so that the brake disc is sprayed and even anti-rust paint. Anti-rust paint will be easily grinded when braking, and the area where the brake pads on both sides will be more eye-catching; the rust agent seems to have some oily lubrication, and the braking ability after spraying the rust rermiscost will not How much is it? This “test” generally no one is going, it is not recommended to try, the brake disc rust does not use.


EDTOR: Day and Auto – Car Science Island


Editor: Tianhe MCN

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