What are the failure modes and causes of brake drums?

Brake drum failure in the process of use, mainly cracking and wear, but from the customer's complaints and claims reflected by the data statistics, mainly the former. That is to say, most of the failure of the brake drum, are in the case of normal wear or even slight wear, that is, cracking and can not continue to use. Based on the failure analysis of the failure parts, it can be concluded that there are three main reasons for failure: (1) The mechanical properties of the casting body are lower than normal requirements. (2) There are casting defects inside the casting, especially shrinkage and porosity at the rounded corners of the flange. (3) The vehicle overload is serious, the brake is frequent and the brake is cooled by water spray, and the mechanical properties and metallography of such failure parts are checked to meet the product requirements.