ПОВЫШЕНИЕ УСТАЛОСТНОЙ ПРОЧНОСТИ ЦЕЛЬНОКАТАНЫХ КОЛЕС ПРИ ИЗГОТОВЛЕНИИ С ПОМОЩЬЮ ОБТОЧКИ ДИСКА

Abstract

Objective: To improve the reliability of wrought wheels by means of fatigue enhancement of the latter, processed by use of disk turning. Methods: The creation in the disk skin layer the correct quality indices, such as magnitude and depth of residual stress occurrence, the level and depth of hammering, surface roughness. In order to fulfill the task, the required material of the tool cutting part is selected, tool design parameters are determined, cutting depth and feed, allowed for the required processing accuracy, surface roughness, residual stress the level and depth of hammering, is calculated. In the process of turning the cutting speeds are to provide optimum temperature in the cutting area, that is the temperature at which the operation in question results in minimum wear ratio of the cutter and induces compression residual stress. Results: It was discovered that the reduction of roughness level, hammering depth and residual compression stress formation increase the fatigue endurance of wheels. Cutting speeds (toolcutting speed, cutting depth and feed) were set for each segment of the disk surface (wheel rim section, midsection and hub section) outside and inside the wheel, in order to achieve optimum quality indices; the method of estimated determination of machined surface quality parameters of freight car wrought wheels was developed, depending on the cutting speeds taking into account temperature and force interactions of the machining tool and the machined part. Practical importance: The method of fatigue enhancement of the rolling stock wrought wheels when processed was developed. The basic requirements to values of wrought wheel discs quality parameters were formulated.