EXPERIMENTAL ASSESSMENT OF CHANGES IN THE STRUCTURE OF FOOD-GRADE ANTI-CORROSION STEEL DUE TO THE USE OF FLOWDRILL TECHNOLOGY

Machining technologies are constantly evolving in line with new material development strategies, with further advances in cutting tools accelerating these changes even further. Growing demands for increased productivity and production efficiency have led us to today's advanced level of technology. Recently, steel structures made of thin sheets and strips, which are processed by bending, three-dimensional forming or pressing, often in combination with technologies such as ribbing, have been increasingly used. Open and closed rolled profiles are increasingly being replaced by more economical and lighter sheet metal strip materials, which provide similar or even higher strength at a significantly lower weight. Flowdrill technology is often used when joining light sheet metal profiles in a demountable manner, which enables the creation of a cylindrical surface necessary for the subsequent shaping of the thread. Flowdrill thermal drilling technology represents an innovative and forward-looking method of producing precise cylindrical housings in thin-walled materials such as sheets, profiles of various shapes and pipes. This technology uses frictional heat, which is generated by a combination of high tool speeds and axial force acting on the workpiece. Frictional heat causes the material to soften, allowing the tool to smoothly penetrate the workpiece and form a sleeve from the displaced material [Rimar 2023]. This process inspired experimental measurements aimed at analyzing the influence of technology parameters on the material. The aim of the experiments was to investigate structural changes in food-grade anti-corrosion steel EN ISO X10CrNi18-8 (17241) as a result of Flowdrill thermal drilling, by analyzing the state of the material before and after the application of this technology. The results of these measurements will bring valuable knowledge to technologists, which will help them choose suitable materials and drilling technologies in practice.