Our cast iron brake block enjoys many advantages including hardness, impact strength and so on. It consists of two parts, the cast iron and the steel support. Both the surface and core of the cast iron have the hardness within the range of 197< HB< 255.
When facing subsequent impacts to the brake block or brake shoe, the steel support must remain intact and attached to the iron places. The connection bridge may possibly become detached but should not show any soundness defects. Separated from the brake shoe, the support must be able to withstand the bend test with cracking or breaking.
Chemical compositions of cast iron
Carbon: 3.0-3.5%
Phosphorus: 1.3-1.5%
Silicon: 1.5-2.0%
Sulphur: 0.1-0.15%
Manganese: 0.5-0.8%
Chemical compositions of steel support
C % < 0.13%,
S % < 0.062%,
P % < 0.062%.