HEAT DISTRIBUTION IN THE TOOTH OF A SAW WITH A MODIFIED GEOMETRY DURING BATCH CUTTING OF COLD ROLLED STEEL

This publication deals with the issue related to the study of the heat distribution in the tooth of a saw with a modified geometry, taking into account the frequency of the process of cutting cold rolled metal with circular saws.

TECHNICAL INSPECTION OF THE STRUCTURE AND DEVELOPMENT OF THE STRUCTURE OF FRAMES WITH COLD-ROLLED THIN-WALLED PROFILES

Cold rolled steel structures have been known since the mid-19th century in the United States and Great Britain. Despite the advances in the development of cold-rolled structures, the level of their use was lower than that of hot-rolled structures. A significant factor that influenced this imbalance in application was the fact that there were no regulations. Into different countries of the world have their own national regulations for the calculation of cold-rolled steel structures, which have many controversies. In the European group includes the norms of the countries of the European Union, Great Britain, Hong Kong, Ukraine, Belarus, Kazakhstan; American group - the United States of America, Canada, Mexico, Australia, New Zealand, Brazil, Chile, Egypt. The regulations of such large countries as China, India and Russia have their own characteristics. The article presents the results of a technical survey of the load-bearing structures of the canopy. The survey was carried out to determine the bearing capacity of the roof load-bearing structures in relation to the location of the solar panels on the roof of the building. The construction of buildings and their structural parts from light steel thin-walled structures (profiles) is carried out in the form of light frames, the frames of which are successively connected into spatial systems. A new lightweight roof covering made of profiled sheet and a frame structure made of cold-rolled P-profile and C-profile elements for roofing and installation of solar panels are proposed. Such a coating is the most industrialized, easily and quickly erected. The analysis of constructive options for the effective placement of the profile of cold-rolled elements and joints of the frame and reinforced concrete run of the coating is carried out. The design of the frame was carried out in the software package " Лира САПР 2013" . The results of the work carried out served to draw up recommendations for restoring the properties of the load-bearing structures of the canopy, the development of design estimates and implementations into construction practice during the reconstruction of the canopy.

Abrasion Resistance and Corrosion Resistance of Chromium-Free Fingerprint-Resistant Zn and Zn-Al-Mg Coating Cold-Rolled Steel Sheets

The wear resistance and corrosion resistance of chromium-free fingerprint-resistant pure zinc and Zn-Al-Mg coated cold-rolled steel sheets were studied by micro-friction wear experiments and neutral salt spray experiments. Two products are worn for a long time with a large load (5N load, 50 times abrasion), the depth of wear zone of Zn-Al-Mg coating product is 9% shallower than that of pure zinc coating product, and the width of wear zone is 15.4% smaller. Both products still meet the requirements of use after corrosion. The corrosion resistance of two products after degreasing treatment was significantly reduced. The Mg and Al in the Zn-Al-Mg coating can hinder the progress of corrosion, so it has better corrosion resistance.