Features of the formation of structure and mechanical properties in rolled products of various thicknesses from low-carbon microalloyed steel produced by casting and rolling complex

The article considers results of the study of microstructure parameters effect on the impact strength in temperature range from 0 to –80 °C in 20 °C increments of Charpy samples with a sharp stress concentrator and Mesnager test pieces with a circular stress concentrator from rolled coils of low-carbon microalloyed steel with various thicknesses. The used roll products were produced in conditions of JSC “Vyksa Metallurgical Plant”. The tests were performed using optical and scanning electron microscopy. It is shown that with the same chemical composition and thermomechanical treatment modes, the metal of smaller thickness (6, 8 mm) is characterized by higher strength properties (on average, by 10 MPa for temporary resistance, by 30 MPa for yield strength) and a margin for viscous properties at negative temperatures at close values of grain score and average grain size corresponding to 10 – 11 numbers according to the State standard GOST 5639. The metal with a thickness of 12 mm has the lowest level of cold resistance, and the temperature of brittle transition is minus 50 °C. Structure of rolled products of various thicknesses has a variation in grain size. Rolled metal of smaller thicknesses have a smaller grains corresponding to number 14, rolled metal of larger thicknesses has a larger grains corresponding to number 8. By conducting electron microscopic studies using the backscattered electron method, it was found that a greater number of large-angle boundaries, which are barriers for brittle cracks propagation, are observed in the 6, 8 mm thick rolled products. The constructed orientation maps of the microstructure showed the presence of pronounced deformation texture corresponding to the orientations <110>||RD (rolling direction) and (<113>...<112>)||RD for rolled products with a thickness of 6 mm.

DETERMINING THE OPTIMAL BACK ANGLE OF A BATCH SAW USING THERMAL FIELD MODELING

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.

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.

Unsettled Issues in Additive Manufacturing and Improved Sustainability in the Mobility Industry

Additive manufacturing (AM), also known as “3D printing,” is often touted as a sustainable technology, especially for metal components, since it produces either net or near-net shapes versus traditionally machined pieces from larger mill products. While traditional machining from mill products is often the case in aerospace, most of the metal parts used in the world are made from flat-rolled metal and are quite efficient in utilization. Additionally, some aspects of the AM value chain are often not accounted for when determining sustainability. Unsettled Issues in Additive Manufacturing and Improved Sustainability in the Mobility Industry uses a set of scenarios to compare the sustainability of parts made using additive and conventional technologies for both the present and future (2040) states of manufacturing.

MODERNIZATION OF LABORATORY ROLLING MILL 150 FOR THE FORMATION OF STUDENTS 'STUDIES OF AUTOMATION OBJECT RESEARCH.

It was fulfilled laboratory rolling mill 150 reconstruction for student’s investigation of rolling mill as automation object. For remote control screw down movement was mounted screw down auxiliary reductor with AC motor, screw down encoder, load cells, inverter with built-in PLC MS-300 and touch panel HMI DOP-103BQ. It was developed PLC and touch panel HMI software for control screw down movement. Software touch panel HMI provide with set point adjustment screw down movement and actual distance monitoring. Software inverter with built-in PLC MS-300 exercise control screw down movement and stopping in position set point without rundown. It was developed software for investigation of rolling force and electrical data’s of mill motor. Software provides measurement and memory of data’s and on-line graphic display. Measurement of rolling force and rolled metal thickness provides ability to build stand stiffness and rolled metal stiffness.

INVESTIGATION OF GEOMETRIC PARAMETERS OF BURRS ON THE PIPE END DURING BATCH CUTTING OF COLD ROLLED METAL

This publication discusses the issue related to the study of geometric parameters of burrs on the end of the pipe during batch cutting of cold rolled metal with disk saws.

Investigation and calculation of a composite arch construction

One way to increase efficiency in the field of construction is to develop and improve new progressive design forms that reduce the consumption of materials, the complexity of manufacturing and erection, and the cost. These include a variety of combined systems, including arched ones. Frameless arch systems have not been widely developed in our country due to the lack of adaptedness of the design concept to Russian climatic conditions, while frame arch systems have a high consumption of materials. It is proposed to improve arch systems by increasing the spatial rigidity of the entire building made of rolled metal due to the combined action of the load-bearing frame and enclosing structures made of corrugated sheets. Thus, it becomes possible to use frameless arches on large spans. The use of such structures opens up wide opportunities for creating coverings that are characterized by lightweight and high technical and economic features.

METAL ROLLING MARKET IN UKRAINE

Background. The production of rolled metal belongs to the field of metallurgy, the mainstay of the Ukrainian economy. Metal rolling is used both in metallurgy and in other industries like aircraft construction, mining, oil and refining. The aim is to characterize the volume of production, sales, imports and exports of rolled metal in Ukraine; comparison of average prices for the investigated product in Ukraine according to trading companies. Materials and methods. The work uses general and special methods of analysis and synthesis, a systematic approach, scientific generalization and comparison of data from scientific sources, as well as open sources of statistical information. Results. In the period from 2015 to 2019, there was a generally positive trend of increasing the volume of rolled metal production in Ukraine, with the exception of some types of rolled metal. During 2015–2019 it should be noted the increase in production of rods and bars almost 2 times; pipes – by 30.4 %; corners, shaped and special profiles – more than 4 times; profiled sheets – by 33.3 %; multilayer panels – by 36.8 %; wire – only 13 %. During 2015–2019 there is a decline in production of some types of rolled metal: profile – by 32.8 %; products for railway and tram tracks – almost 2 times; fittings for pipes – by 34.7 %. The largest amount of rolled metal in Ukraine in 2019 was produced by Arcelor­Mittal Kryvyi Rih – 4.7 million tons. In 2019 the largest share of rolled metal produced by Metinvest Holding LLC was produced by Zaporizhstal (3.5 million tons) and Ilyich Mariupol MK (2.6 million tons). A fairly wide range of rolled metal products is sold on the Ukrainian market. Sales of rolled metal products in Ukraine during 2015–2019 increased by 14 %. Volumes of rolled metal exports during 2015–2019 significantly exceeded imports. This trend is natural, because on the territory of Ukraine there are quite powerful producers of rolled metal, which are able to compete at a high level with foreign ones. Conclusion. During 2015–2019, there is a tendency to reduce production volu­mes and increase sales of rolled metal. Exports significantly exceed the volumes of rolled metal imports. In the context of the coronavirus pandemic, rolled metal producers need to opti­mize their activities by modernizing production and implementing investment projects in their activities to increase their competitiveness.