Machine Learning-Based Models for the Estimation of the Energy Consumption in Metal Forming Processes

This research provides an insight on the performances of machine learning (ML)-based algorithms for the estimation of the energy consumption in metal forming processes and is applied to the radial-axial ring rolling process. To define the mutual influence between ring geometry, process settings, and ring rolling mill geometries with the resulting energy consumption, measured in terms of the force integral over the processing time (FIOT), FEM simulations have been implemented in the commercial SW Simufact Forming 15. A total of 380 finite element simulations with rings ranging from 650 mm < DF < 2000 mm have been implemented and constitute the bulk of the training and validation datasets. Both finite element simulation settings (input), as well as the FI (output), have been utilized for the training of eight machine learning models, implemented with Python scripts. The results allow defining that the Gradient Boosting (GB) method is the most reliable for the FIOT prediction in forming processes, being its maximum and average errors equal to 9.03% and 3.18%, respectively. The trained ML models have been also applied to own and literature experimental cases, showing a maximum and average error equal to 8.00% and 5.70%, respectively, thus proving once again its reliability.

Modeling of ring billets rolling on radial-axial ring-rolling mill

On the basis of radial-axial rolling of ring billets, resource-saving technologies for metal forming have been created. Determining the rational parameters of this process is the actual scientific and technical task at development of new profiles. The method of three-dimensional finite element modeling is the most effective tool for improving the technological conditions of ring rolling process. However, as practice has shown, the finite element modeling method requires adaptation to each process of metal forming. This is the subject of the present work. The expediency of using dependency for calculating the metal flow stress for finite-element modeling of ring-rolling processes is substantiated. This dependence was developed on the basis of a theory that takes into account the chemical composition of structural carbon steel, its temperature, strain rate, accumulated deformation, and also the processes of dynamic transformation of the metal structure during hot rolling. A computer program for automated determination of dependency parameters has been developed. The analysis of the accuracy of the obtained dependence was performed in relation to the experimental data. In the course of these calculations, the method of automated determination of the metal flow stress was used by spline interpolation of the experimental data included in the computer database of digital information for a particular steel grade. The average relative error of calculated values of the metal flow stress was 8 % relative to the experimental ones. An improved method is proposed for calculating the parameters of ring billets rolling and reaching the required growth rate of the ring diameter implemented in a finite element modeling system, which is similar to the way the control system of the ring-rolling mill works in solving the same problem (reaching the required growth rate of the ring diameter) when implemented appropriate rolling in practice. When calculating the size of the compression, the iterative process and the method of half division were used. The average deviations of calculated values of the parameters of ring billets rolling from the experimental did not exceed 12.4 %, which makes it possible to apply the proposed approach to study the patterns of the rings rolling process and to improve the rolling technology.

Development of Radial-Axial Ring Rolling Experimental Equipment and Calculation of Ring Rolling Forces

By referring to the heavy duty radial-axial ring rolling mill in production, a radial-axial ring rolling experimental equipment was designed and developed. Based on the principle of similarity, the mathematical relationship and calculation method between experimental rolling forces and actual ones in the process of radial-axial ring rolling were established. This experimental equipment has many advantages, such as compact structures, full functions, small deformation and more safety and reliability, which can be used in experimental study and calculation of ring rolling forces.

Rolling Theory Analysis and Forces Calculation of Heavy Cylinder Rolling Mill with Two Drive Rolls

Took the heavy cylinder rolling mill as subject investigated, which is used to produce the nuclear power cylinder, the large hydrogenation reactor cylinder and the coal liquefaction reactor cylinder. And the cylinder rolling mill has two drive rolls which is different from conventional ring rolling mill. The rolling theory of heavy cylinder rolling mill was researched deeply based on mechanism method, including the biting condition, the plastic penetration condition, the feed condition and the feed velocity condition; the rolling force parameters of heavy cylinder rolling mill with two drive rolls were calculated based on the slip line method (SLM) and finite element method (FEM), and the simulation and industrial experiment were done; the influences of main technology parameters such as feed velocity, friction coefficient and temperature on the rolling force parameters were analyzed. The results show that the error of calculated rolling force and the measured value is less than 5%, which proves that the basic conditions deduced by theory method are correct, the models established based on SLM and FEM are correct. And with the increase of feed velocity, the rolling force increase, after a rolling circle, the rolling force fluctuates at a constant value; with the increase of friction coefficient, the rolling force increase; with the increase of initial temperature, the rolling force decrease.

Thermo-Mechanical Coupled Analysis of Heavy Shell Ring Hot Rolling Mill with Two Drive Rolls

The heavy shell ring rolling mill which produces the large shell ring used in nuclear power, large-scale hydrogenation reactor and coal liquefaction reactor was taken as subject investigated. Because the size of shell ring is very large and the material of shell ring is special, the double drive rolls was taken in the shell ring rolling mill. Based on the elastic-plastic FEM and MARC software platform, the three dimensional thermal-mechanical coupled model of shell ring rolling process was built in this paper. First, the heat simulation text of the shell ring material has been carried out on the Gleeble-3500 thermal simulation test machine and the material properties were obtained. Then, considering the characteristics of heavy shell ring hot rolling mill with two drive rolls, the key problems such as geometry, material and thermo-boundary conditions were solved, the thermo-mechanical coupled finite element model of heavy shell ring hot rolling has been establised. At last, based on explicit dynamic FEM, the thermo-mechanical simulation of heavy shell ring rolling process was made. The stress field, strain field and temperature field were studied, the metal plastic deformation and its influence factors were investigated. The conclusions are agreement with the real rolling process. The conclusions are significant for designing equipments of shell ring rolling mill and developing new rolling schedule.

The Design of Automatic Control System for Large-Scale Aluminum Ring Rolling Mill

Large –scale aluminum ring rolling mill is the core of ring rolling ,it is required for automatic control system to realize high precision and fast response.Based on the configuration of the equipment, characteristics of ring rolling and the process flow of production, the paper not only studied the Control principle of the automatic control system but also designed the control scheme of software and hardware. The core of system is PLC. The system can effectively control hydraulic system, measurement system, feeding servo system by the cooperation of PLC and human machine interface (HMI). It realized fully automatic operation under the ring rolling mill close-loop control. The high precision control and safe operation can be realized by using multi network communication technology and advanced full AC drive system .The rolling quality of rings is high. The design accords with the control logic requirements of rolling process control. The control system is smooth and reliable.

Influences of Technology Parameters of Heavy Shell Ring Rolling Mill with Double Drive Rolls Based on FEM

The heavy shell ring rolling process was taken as subject investigated. Because the size of shell ring is very large and the material of shell ring is special, in order to make the shell ring to be bitten smoothly and make the rolling process stable, the double drive rolls was proposed in the shell ring rolling mill. The thermal simulation test of heavy shell ring material was made on the Gleeble 3500 thermal simulation test machine. Based on FEM, the three dimensional thermal mechanical coupled model of shell ring rolling process was built in this paper. The influences of process parameters on the stress field, strain field and mechanical parameters were investigated. Simulation results show that, with the increase of feed velocity, the strain of shell ring increases, the forging penetration condition becomes good; With the increase of friction coefficient, the equivalent plastic strain of shell ring surface layers increases, the equivalent plastic strain of shell ring middle layers has little change. The conclusions are significant for designing equipments of shell ring rolling mill and developing new rolling schedule.

Optimal Design of the Guide Mechanism of Vertical Ring Rolling Mill

This paper firstly analyzes the features of the spring-loaded type guide mechanism of D51 series vertical ring rolling mill. Then a reliable parametric virtual prototyping model of the guide mechanism is developed in software ADAMS. In addition, the optimal design of the guide mechanism is conducted. The minimum spring force is selected as the objective function, the dimensions of the parts of the guide mechanism are set to the design variables and the working condition is taken as the design constraints. The optimal guide mechanism is obtained after optimization, compared with the original structure, the spring force is decreased by 50.5%, and the guiding force is also decreased to a reasonable value. The research results can help to design the guide mechanism of the D51 series vertical ring rolling mill.