Providing steel with an approximate application of the mechanical properties of wire rod 5.5-6.5 mm from sreel grades 70-75 based on a conventional twin of the Stelmor process

Abstract

In 2019, the air-cooling line of Mill 170 of PJSC MMK (Magnitogorsk Iron and Steel Works) was upgraded. The main task of modernization was to obtain wire rod sorbitized in the initial state. The use of such products makes it possible to abandon one intermediate heat treatment operation in the wire production process, and should also ensure the stability of the mechanical properties of the finished wire of the entire size range of OJSC MMK-METIZ. On the part of OJSC MMK-METIZ, the following high requirements were imposed on the uniformity of the mechanical properties of the wire rod obtained at the mill -no more than 40 N/mm 2 along the length of the convolution, 50 N/mm 2 along the length of the coil, 60 N/mm 2 within the melt. When analyzing samples of rolled products from steel grades 70-75 with a diameter of 5.5-6.5 mm, it was found that compliance with the requirements in the modes operating at the mill is difficult. By the order of PJSC MMK, as part of scientific research on the development of wire rod production technology using a digital twin of an air cooling line, a mathematical model was developed, the adequacy of which was proved by developing rolling modes based on it, followed by evaluation of the resulting product. Upon further analysis of the obtained rolled products, it was found that the products manufactured according to the new modes meet the requirements for uneven mechanical properties along the length of the convolution and the coil to a greater extent.

Experience of putting into practice and development prospects of digital twins in section rolling technological systems

“…-DT for the part of technological process is created as a model [9], which has formalized system (description of mathematical models and experimental results is presented in the work [10]) as well as input and output signals (data flows) with the following sources: level 0 of ACSTP (operative information about the process state); information from the previous technological stage about billet, state of equipment and internal systems (for example, accounting system for rolling rolls); additional network of measuring remedies (industrial internet of things IIoT) [11. 12];…”

“…-creation of the pilot DT of the part of technological process with manufacturing products at the rolling mill 170 of MMK (implemented for the air cooling line) [10];…”

“…The mathematical model, which was used as the base for this digital twin, was adapted to the technological conditions and is characterized by wide area of application [14][15][16][17]. This DT was successfully tested, the results of its operation were put into practice as modified cooling procedures and introduced in the technological specification of the rolling mill, while DT itself was put into operation [9,10,13]. Interaction structure in this DT (it operates Offline in advising conditions) and screenshots of its interfaces are presented on the Fig.…”