Методические особенности дефектоскопии сортамента роликов прокатного стана после их восстановления

Abstract

В работе представлены результаты разработки методики ультразвуковой диагностики состояния дефектности малыхпартий роликов прокатного стана разного сортамента, на разных стадиях их восстановления после разрушения рабочей поверхности в процессе эксплуатации. Проведен сравнительный анализ эффективности обнаружения дефектов в изделиях определенного типоразмера с помощью стандартного дефектоскопа типа УД2-12 и с помощью оригинальной установки, адаптируемой к особенностям исследуемого объекта. Установлено преимущество предлагаемых методических особенностей ультразвуковой дефектоскопии восстановленных прокатных роликов в условиях интенсивных помех, вызванных характером приповерхностного прозвучивания и влиянием границы раздела между телом роликов и наплавленным металлом.The paper presents the results of developing a technique for ultrasonic diagnostics of the defectiveness of small batches of rollers of a rolling mill of a wide range of similar products. The study was carried out at different stages of the restoration of rollers after the destruction of the working surface during operation. A comparative analysis of the effectiveness of defect detection in products of a certain standard size was carried out using a standard UD2-12 flaw detector and using an original installation that was adapted to the features of the object under study. The advantage of the proposed methodological features of ultrasonic flaw detection of reconstructed rolling rollers in the conditions of intense noise caused by the nature of near-surface sounding and the influence of the interface between the roller body and the weld metal is established. To test the parameters of the sounding signal, to select the most efficient converter, the relative location of the converter and the roller, a test experiment was conducted on deliberately defective rollers. Some of the rollers after the flaw detection were cut to determine the type and size of defects and their comparison with the results of nondestructive testing. According to the results of the test experiment, optimal modes of probing of controlled products, frequency and time characteristics of ultrasonic signals, and the type of converter used were selected. For the testing of the rejection level, 2 batches of rollers (10 and 18 pieces) were manufactured, manufactured using different deposition techniques. Processing of the received statistical data has allowed to develop practical recommendations on revealing of defective products in an initial stage of technological process on restoration of rolling rollers.