Тернопiльський національний технiчний унiверситет iменi Iвана Пулюя
Abstract
Розроблено математичну модель для визначення температурного поля в області деталі перед заливанням розплавленого рідкого металу в створений технологічний тигель залежно від питомої потужності теплових джерел нагрівання, коли температура на поверхні деталі перевищує температуру Кюрі. Температурне поле створюється в області деталі з метою зменшення градієнта температури після заливання розплавленого металу в створений технологічний тигель, та з метою покращення дифузії розплавленого металу в матеріал деталі. За допомогою розробленої математичної моделі проведено дослідження залежності температури від частоти і сили струму в індукторі та 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
Mathematical model of creation the temperature field for the case, when the temperature within the entire region of worn parts exceeds the Curie temperature, was built. Temperature is created in a part to reduce the temperature gradient after pouring of the molten metal in the created crucible in order to increase the wheel and to improve the diffusion of the molten metal in the material of a part. The temperature in the part is described by the differential equation as
Investigation of the temperature field in the part during the process the obtaining of temperature 1450°C on the rim of the part at different heating times and different frequencies, has been carried out.
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 cooling of base metal with cast metal in the crucible being followed. At temperature 1450–1600°C both the filled liquid metal and prepared on the border between them the base metal being 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
