Braking systems on modern freight cars act in a kind of tribological triangle: brake shoe – wheel – rail. Kinetic energy stored by the car during movement at braking due to friction is converted into heat, which is distributed between a brake shoe and a wheel. Numerous studies in recent years have proved that up to 60% heat is generated in the wheel when using iron shoes and up to 95% using composite shoes. During operation the material of the wheel is subjected to thermal impact, the intensity of which depends directly on braking modes and motion parameters of the rolling stock. Repetitive heating and cooling of wrought wheels have a significant effect on the kinetics of their stress-strain state.The kinetics of the stress-strain state in operation is determined by the scheme and the level of residual stresses, formed during heat treatment in the manufacture of wheels, as well as stresses and strains associated with mechanical and thermal loading. The level of residual technological stresses in the wheel with which it comes into operation, in some cases, is one of the main indicators of quality, reliability and durability. The combination of stress-strain state with residual technological stresses under adverse conditions, such as low temperature, presence of microdefect or local deviations in the formation of the microstructure can lead to formation of cracks in disc or brittle fracture of wheel that has been repeatedly confirmed by experts.The objective of the authors is to investigate impact of high speeds on wrought wheels, in particular in case of thermal loading: both heating and cooling. Methods and software developed in MIIT allow computer simulation of the kinetics of thermal, thermal deformation and deformation processes in nonlinear unsteady statement with account of kinetics of the structural state at each step of the solution, which allows to analyze the current state of the structural element using a wide range of technological and operational loadings throughout the life cycle.Continuing the theme of modeling of wrought wheels thermal loading, described in previous publications, the authors on the basis of the calculation and simulation methodology, developed with their participation in order to determine heat intensity in the system «wheel-brake shoe», clarify the features of influence of high speed of car’s movement along the rails on the values of maximum temperatures on the wheel surface during braking. The study confirmed theoretically grounded assumptions that increasing speeds significantly affect the value of the maximum temperature on the surface of wrought wheel at the time of the end of braking, as well as the complex of mechanical properties, kinetics of structures, conditions causing formation of cracks, metal chipping and other defects that endanger the operation of the rolling stock.Продолжая тему моделирования тепловых нагружений цельнокатаных железнодорожных колёс (см. «МТ», 2014, № 5), авторы статьи на основе созданной с их участием методики расчета интенсивности выделения тепла в системе «колесо–тормозная колодка» уточняют особенности влияния высоких скоростей движения вагона по рельсам на значения максимальных температур на поверхности колёс в процессе торможения. Во внимание берутся весь комплекс механических характеристик, кинетика структур, условия для образования трещин, выкрашивания металла и прочих дефектов, создающих угрозу эксплуатации подвижного состава
