The common problems in the production process of brake shoes mainly involve materials,processes,and quality inspection.The following is a specific introduction:

Material issues

Uneven material:The material used to produce brake shoes exhibits uneven composition and performance.For example,uneven distribution of various elements in cast iron brake shoes can lead to differences in hardness,strength,and wear resistance in different parts of the brake shoes,affecting braking effectiveness and service life.

Unstable quality of raw materials:The quality of raw materials fluctuates greatly,such as resin,fiber and other raw materials used in the synthesis of brake shoes.If their performance indicators do not meet the requirements,the friction performance,heat resistance and mechanical strength of the brake shoes will not meet the standards.

process problems

Casting defects:During the casting process of cast iron brake shoes,defects such as porosity,sand holes,and shrinkage porosity may occur.These defects will weaken the structural strength of the brake shoes,leading to cracks or even fractures during the braking process,which affects driving safety.

Improper pressing process:The composite brake shoe adopts pressing process.If the pressing pressure is insufficient,the holding time is not enough,or the temperature control is improper,the density and hardness of the brake shoe will not meet the requirements,and the bonding between the layers will not be tight,which is prone to delamination and reduces the overall performance of the brake shoe.

Heat treatment issue:The heat treatment process in the production of brake shoes is crucial.If the heat treatment parameters are not accurate,such as heating rate,insulation time,cooling method,etc.,improper control can cause the metallographic structure of the brake shoes to not meet the requirements,thereby affecting their hardness,toughness,wear resistance and other properties.

Quality inspection issues

Imperfect testing equipment:Some brake shoe manufacturing enterprises have insufficient accuracy or aging testing equipment,which cannot accurately detect various performance indicators of brake shoes.For example,inaccurate friction coefficient testing equipment can lead to misjudgment of brake shoe friction performance.

The testing standards are not strict:Enterprises do not strictly follow relevant standards for testing,or relax the testing requirements for some key indicators,resulting in some unqualified products entering the market and posing hidden dangers to railway transportation safety.