Property Study And Analysis On Forging Steel Breaking Material For High-speed Train

Along with the application of the railway security, heavy load, speed increase and high speed plan, the railway braking material has become an important part of railway locomotive and vehicle system, serving as a crucial factor in railway transportation security and cost. Based on the application of brake disc made of forging steel on CRH2, this paper uses MM-1000 friction equipment to imitate the condition of real emergency braking, with an aim to investigating properly the friction and wear resistance properties and wear mechanism under the condition of high braking energy.This article focuses on the following aspects:Examination of physical properties and mechanical properties of two kinds of forging steels is carried out, with A1 meeting Japanese standard and B1 made by Beijing Jiao tong University, China. Through analyzing and comparing specific features of two forging steels, such as strength against tensile, density, hardness, specific heat and thermal conductivity, this paper demonstrates that although differences between them are quite limited the specific heat and thermal conductivity of B1 is much better than A1, which in consequence proves that the high-temperature mechanical property of B1 outweighs A1.Examination respectively of the influence on the friction and wear resistance property of two forging steels due to load and velocity will be carried out, with pair material being copper base powder metallurgy material. In addition, this paper also discusses the friction property and mechanism of two forging steels when high-speed train is under the condition of braking state. Under the help of TPF-1 microscope, SEM and Spectrum analyzer, this article analyzes the compositions,morphology and properties of friction surface layer, and based on such effort, discusses the formation,serving behavior and function mechanism of friction surface layer during the emergency braking process.By imitating the braking process of high-speed train, this paper proves that compared with A1 the friction coefficient of B1 pair is more stable, its wear rate is lower, the threshold of thermal recession is higher, and therefore the friction and wear resistance properties are better in that a stable friction surface layer is formed on the wear surface during the emergency braking process and the surface layer which is homogenous high-micro hardness and cover the entire surface can prevent both of the pair from further wear.