Papers by Author: Tomasz Garstka

Abstract: Nowadays methods of hot-rolled sheets should ensure high mechanical and plastic properties of sheets, in-line rolling. Such technologies require application of devices for accelerated cooling of a band after last deformation. The essential thing in this process is selection of an appropriate positioning of the cooling intensity. The paper presents results of the cooling intensity for the selected air-water nozzle. On the basis of the results, the map of distribution of heat transfer coefficient for the nozzle to the surface of the cooling was performed. These tests were carried out for different settings of water and air. The research was carried out for high-strength steel. The obtained results allow executing of computer simulation of the impact of cooling intensity on the final product’s structure.

Abstract: In many cases of residual stress testing by Barkhausen method, the microstructure of the sample used for calibration procedure and tested material is fairly different though made form the same steel grade. These differences can be observed even in the same investigated product, for example, in steel shapes. Due to this fact, this paper presents the preliminary results of experimental investigations of the influence of microstructure state (modified by heat treatment) on Barkhausen noise parameters and, finally, on residual stress measurement by Barkhausen method.