Mathematic modeling of the induction heating in recuperating of the operation characteristics of culinder-shape parts

Розроблено математичну модель для визначення питомої потужності теплових джерел, які виникають у результаті індукційного нагріву масивних циліндричних тіл. Такий нагрів використовується в технологічних процесах відновлювання експлуатаційних властивостей коліс залізничного транспорту методом нарощування їхньої робочої поверхні за допомогою заливки рідкого металу і схоплення його з підготовленою для відновлювання поверхнею. За допомогою розробленої математичної моделі проведено дослідження залежності питомої потужності теплових джерел від частоти і сили струму в індукторі й тривалості нагрівання.The increase of durability and reliability of parts and operating members of machines and mechanisms is one of the most important issues for various sectors of the economy of Ukraine. In order to improve the parts wear resistance during operation, their working surfaces are strengthened by various surfacing methods. Available surfacing processes of worn working cylindrical bodies, induction ones in particular, possess some disadvantages: relatively low productivity, large energy consuming and uneven thickness of the surfacing metal. To improve these characteristics, theoretical foundations of improving welding technology and increasing of its energy efficiency should be developed. A mathematical model to determine the specific power of heat sources, resulting from the induction heating of huge cylindrical bodies, has been developed. This type of heating is applied in industrial processes for the recuperating of rail transport wheels performance characteristics by growing of their working surface and pouring with a liquid metal and connection of it with prepared for recuperation surface. Applying the developed mathematical model, the investigation for the dependency of heat source specific power on the frequency and current strength in the inductor and heating duration has been conducted. It was found that for the development of the recuperation technology of worn working surfaces of cylindrical shape bodies it is necessary to heat its prepared end area up to 1300–1450°C to prepare the crucible for pouring in it the molten metal and further cooling of base metal together with the poured in the crucible. At temperature 1450–1600°C both the poured liquid metal and prepared on the border between them the base metal are in the liquid state and in the amount of liquid metal and austenite, that is, conditions for their mutual mixing and diffusion will be created to promote their real joining

Optimum control of heating of thin circular discs to create a given temperature field under stress constraints

The problem of finding the power of heat sources, which is necessary to create a temperature field close to the given one in a given time in a round plate, with minimal energy consumption and stress restrictions, is considered