Özgün Yakar, Resonance Institute, Turkey

Co-Author:
murat ışık, isdemir

Abstract:
Hot rolling mill is a key section of a steel plant. The section produces vast amounts of steel sheet with different sizes and grades which are used extensively on automotive, pipe, construction and white goods industry. With respect to these high production rates, machinery reliability is on top importance for the plant. Rolling mills which need to work continuously without a flaw, consist of machinery that must be reliable in long term. Hot rolling mills usually have one or two rougher mills with an attached edger and 6 or 7 stand finishing mill. Each of these divisions contain nearly the same machine elements which are mostly a main drive motor, a gearbox to reduce speed and increase the load and a pinion stand to get a double output which are turning different direction to be able to drive the rolling stands. Each of these machines have very critical parts like roller bearings and reducers that have to be perfectly and continuously monitored in order to prevent developing failures. The article contains the detailed structure of the online condition monitoring system which is implemented on the hot rolling mill plant in Isdemir – Iskenderun/TURKEY. In the last section of the article a bearing failure which was detected with the help of the online system has been shared. Key Words: hot rolling, condition monitoring, vibration analysis, bearing fault, advanced diagnostic analysis, process parameters

Matteo Tomba, PERT Srl, Italy

Co-Author:
Nicola Tomba, PERT Srl

Abstract:
The reduction of energy consumption and the use of low-impact facilities, are now issues that every steel producer faces, since plants that pollute generate high costs and a high degree of mistrust on behalf of civil society, that perceives these works as a threat to its health.This article takes into account the electricity consumption resulting from the use of different types of rolling stands currently on the market, as well as the environmental impact due to their operation and considering the different technical characteristics of each type of stand. As well as introducing several advantages at a technical and economic level (reduction of CAPEX and OPEX) the new revolutionary PERT BS stands also lead to considerable savings in electricity, drastically reducing consumption. In the first analysis, we take into account the greater difference between BS and housingless — i.e. the absence of spindles with regards to the BS. From the point of view of energy saving, it is clear that the elimination of spindles involves a considerable simplification of the kinematic chain that allows the transmission of motion from the electric motor to the rolls.

Christian Overhagen, University of Duisburg-Essen, Germany

Co-Author:
Linfeng Zhu, University of Duisburg-Essen
Wanyun Mao, University of Duisburg-Essen
Maolin Liu, University of Duisburg-Essen
Sichen Zhou, University of Duisburg-Essen
Kaiqi Fu, University of Duisburg-Essen

Abstract:
Classical approaches of roll pass design (RPD) for finished full sections require a two-step method. First, main grooves are designed according to a predefined elongation distribution to meet the requirements of the intended process in terms of temperature evolution, power demand and section tolerances. In the second step, the intermediate grooves are designed in order to fulfill prescribed filling ratios, taking into account the specific spread behaviour of the rolling process. This process is a trial-and-error method and often requires a high number of iterations to yield a satisfying solution for all passes. Extra complexity exists for diamond-diamond pass sequences in which a final square section is produced in few passes without predefined main grooves with similarities to the three-roll process, suffering from the same restrictions. To speed up the design process and to initiate a framework for a fully-automated solution, the RPD problem is solved by a machine-learning method in the present study. Using the industrially approved RPD software MPC developed at our research group, we generated training data for the pass sequences round-oval-round, square-diamond-square and diamond-diamond-square in the two-roll process, as well as round-round and round-hexagon in the three-roll process, each for a range of roll diameters and total reductions. The fully-connected neural network trained with these data is able to predict pass designs within the trained data ranges. Verification data was generated which does not coincide with the training data to test the network against overfitting. Model results are presented and cross-validated against the analytical RPD model. The resulting ML pass design model is implemented in Python using the PyTorch library. Source code for including the parameters of the neural network will be published for third-party evaluation.

Amit Ahsan, SECOPTA analytics gmbh, Germany

Co-Author:
Christian Bohling, SECOPTA analytics GmbH

Abstract:
Due to modern days automation processes inside rolling mills, the risk of material mix-ups is pretty low. However, given the rising demand for smaller production lots and the constantly growing number of steel grades, reliable material identification along the entire process chain is still one of the highest concerns. The current state-of-the technologies (e.g., spark, magnetic induction testing) fall short to guarantee a 100% reliable check at the end of the rolling process (e.g., before shipment). On the other hand, at the beginning of the rolling process, manual activities such as picking input or semi-finished material from the storage to charge into reheating furnace often leads to material mix-ups as well. Particularly, when safety-critical components are concerned, a mix-up can have catastrophic consequences (e.g. shipment cancellation, penalty charges, loss in reputation). With fully integrated precleaning (e.g. scale, decarbonization layers), SECOPTA developed LIBS (laser-induced breakdown spectroscopy) based sensor can analyze every moving bar (bright or black) more precisely (with respect to heat/ melt shop value) at the speed of 2 m/sec. Additionally, it can check each billet or ingot before the charging of reheating furnace assuring maximum safety without any human interference. Depending on the risk of mix-up, fiberLIBS can be integrated into the existing process (e.g., finishing line, NDT line, before reheating furnace) and fully compatible with Manufacturing Execution System Systems (MES), ensuring industry 4.0, 100% mix-up testing with significantly low maintenance and operating costs. Since 2019, SECOPTA has carried out multiple successful installations in highly reputable special steel manufacturer facilities and years of 24/7 process operation have proven that fiberLIBS can detect out-of-spec material with more than 99,9 percent reliability. The paper followed by the Estad presentation will introduce this inline LIBS-based Positive Material Identification (PMI) technology and discuss its reliability with real-life process data.

Mark Kreso, EMG Automation GmbH, Germany

Co-Author:
Timo Gemmer, EMG Automation GmbH
Jens Bublitz, EMG Automation GmbH

Abstract:
Electrical sheets - along with magnets and lacquered copper wires - are key components for the manufacturing of electric drives. The projected growth of e-mobility will increase the demand for electrical sheets for the automotive industry from 100 thousand tonnes in 2018 to about 1.2 million tonnes in 2030. Quality assurance and the control of quality costs for electrical sheets thus determine the profitability of motor manufacturers to a large extent. The thickness and homogeneity of the insulating coating play a special role here. Beta transmission, used until now to determine mass per unit area, thickness, and density, will soon reach the limit of its availability. Different isotopes (krypton, strontium, promethium) are used for different weight ranges, but Promethium can only be purchased for the next 1 - 2 years. The EMG SOLID® systems, so far used for the quantitative determination of lubricant layers on sheet metal, offer an ideal replacement. Especially laser-induced fluorescence (LIF) can be used to reliably determine the desired measuring data online. The system parameters, e.g., laser excitation and observation wavelength of the fluorescence, detector sensitivity or signal timing are specifically adjusted to guarantee an optimal system adaptation to the respective type of coating. An additional reference measurement on uncoated sheet surfaces, e.g., by a suitable backscatter method, represents a further possibility for optimising this application. Coating thicknesses between 0 - 7 µm (incl. dark pigmented coatings) could be successfully determined. The methods are designed for inline or online measurement operation, also in traversing mode with typical travel speeds of up to 1 m/s. The EMG results clearly show that quantitative detection of insulating varnishes on electrical sheet in the micrometre layer thickness range is reliable possible. This paper describes the technological background of the method and shows laboratory as well as first application results.

Tae Jun Park, Hyundai Steel Co., Korea, Republic of

Co-Author:
Gang Won Lee, Hyundai Steel Co.
Hyeon Woo Park, Hyundai Steel Co.
Myoung Hwan Choi, Hyundai Steel Co.
Yun Kyum Kim, Hyundai Steel Co.

Abstract:
So far, many researchers have made various efforts to improve the surface quality for automotive exterior sheet steel. Dross and Ash defects, which are major defects, must be effectively controlled to ensure the surface quality of automotive exterior sheet steel. In order to control these defects, various factors such as chemical composition, thermal equilibrium, and level management of galvanizing bath must be considered. This research relates to a process performed within a dam type snorkel included in the lower part of the snout facility, and this research improved an area where it was difficult for workers to monitor and control in real time and made the process smart. For this purpose, we’ll use camera and computing vision technology to analyze floating matter and flow rate of molten zinc on snorkel with optical technology to develop alarm system for operational risk, develop automatic control system linked to other facilities, and use it for process analysis. We’ll introduce the current status of technology development and additional process digitization plans using optical analysis technology of computing vision for the production of high-quality automotive exterior materials.

Enrique Frixione, OG Technologies, Inc., United States

Co-Author:
Chang Tzyy-Shuh, OG Technologies, Inc.
Michal Podermanski, Moravia Steel a.s

Abstract:
In 2018 and 2019, Třinecké Železárny implemented a project to replace the surface inspection equipment using eddy currents in the two-strand wire rod rolling mills. The imaging-based surface inspection system was selected for installation in the wire rod mill based on its proven defect detection capabilities in many SBQ wire mills. The first unit was installed in 2018, with a second installation to follow in 2019. The wire rod mill quality team at Třinecké Železárny found the range of quality data, including images of defects, to be beneficial. In addition to real-time detection and alarms resulting in mitigation of quality failures, the newly available surface quality data has led to the resolution of various surface quality issues and the development and implementation of a coil grading model based on customer requirements, wire diameter, material grades and surface quality data. The results of the quality scorecard, along with images of defects, are displayed on a large screen at the quality control station, providing all line operators across all mill shifts with a clear, consistent and repeatable assessment of the quality of each rolled coil. The introduction of imaging-based surface inspection systems, coupled with improvements to the rolling process that enable surface quality data, has contributed to the best quality performance in 2021 since the wire rod mill began operations in the mid-1970s. This document maps the processes, experiences and successes of surface quality improvement at the wire rod mills of Třinecké Železárny.

Alberto Nardini, POMINI Long Rolling Mills Srl, Italy

Co-Author:
Daniele Biagini, POMINI Long Rolling Mills S.r.l.

Abstract:
The uses of long quality products (SBQ) increasingly require high metallurgical properties and excellent tolerances. Rolling these products therefore entails a fast process that requires high speed control and communication capabilities, with fast response electromechanical-hydraulic control systems. To offer high process stability, POMINI Long Rolling Mills has developed a finishing-sizing unit equipped with an AGC (Automatic Gap Control) system for the automatic control of the gap between the rolls, able to dynamically maintain the required dimensional tolerances. The finishing-sizing unit is placed at the end of the continuous train and consists of two vertical and horizontal two-roll stands. To control the size of the bar, the AGC system manages the dynamic positioning of the rolls, whose light variation is applied by means of synchronous screws operated by a hydraulic servomotor with proportional valve. With the finishing-sizing unit enslaved to the AGC system, a minimum tolerance of 1/5 DIN for round bars can be obtained. The same system is applicable, with the applicable changes in the product characterization, even with flat bars, for which a minimum tolerance of 1/4 DIN can be obtained. This paper describes the main process and features of the system. KEYWORDS: HYDRAULIC POSITION CONTROL, AUTOMATIC GAP CONTROL, FINISHING SIZING STAND GROUP, AGC CONTROL

Pavel Vitoslavský, UVB TECHNIK s.r.o., Czech Republic

Abstract:
There are continuous contact and noncontact thickness gauges used in cold rolling process. The spectrum of noncontact measuring instruments has considerably expanded thanks to the development of new technologies and implementation of wide range of physical principles. The paper briefly reviews the types of noncontact measuring devices most frequently used today including laser thickness gauges. However environment including vapour, presence of oil or any liquid on the strip, chemical composition of the material, type of strip surface can be critical for noncontact measurement against the contact type. We will also mention an example of a unique application where contact thickness gauge is used for calibration of noncontact measuring gauge, e.g. for rolling aluminium or bimetal strips to provide safe, fast and accurate measurement. Consequently more detailed attention is given to the most important parameters and advantages of a contact thickness gauges that show us this measurement can still successfully compete with the noncontact measuring instruments and in some applications may even be the only one solution.

Manfred Kügel, SAS Institute Software GmbH , Austria

Abstract:
This paper presents a method for minimizing the formation of cobbles in hot strip mills using data analytics, which was successfully implemented and proven in real-life production. The paper provides learnings from the implementation of this use case. Cobbles can cause significant damage, safety issues and production delays, resulting in financial losses. By analyzing data from various sources, patterns and trends in the production process that lead to cobbles can be identified. Using this information, real-time recommendations are provided to the process engineers and operators, who can then make adjustments to the process to prevent the formation of cobbles and improve overall efficiency. The results of the data analysis, implementation of preventative measures, and the real-life production are discussed, showing a reduction in the occurrence of cobbles and an improvement in overall efficiency. The paper concludes by providing valuable insights and learnings that can be applied to similar use cases, and how the use of data analytics, coupled with real-time recommendations, is a powerful and effective tool for identifying and mitigating the causes of production issues in hot strip mills.

Horst Krauthäuser, IMS Messsysteme GmbH, Germany

Co-Author:
Tobias Terlau, IMS Messsysteme GmbH
Lennart Möller, IMS Messsysteme GmbH
Cornelia Ionescu, Tata Steel Ltd
Frenk van den Berg, Tata Steel Ltd
Danique Fintelman, Tata Steel Ltd
Stefan Melzer, Tata Steel Ltd
Ernesto Montagna, SEGAL
Alexandre Lhoest, Drever International sa
Amedeo Di Giovanni, Drever International sa
Ulrich Sommers, SMS group
Christoph von der Heide, SMS group

Abstract:
High energy cost and increasing requirements on the mechanical properties of modern steel causes high demand for sophisticated process control in the heat treatment of the flat steel production. X-ray diffraction is a technology, which is traditionally used in the laboratory but recently also as online measuring device in steel production. The X-ray Controlled Annealing Process (X-CAP®) uses the measured phase fraction in front of the rapid cooling for production of AHSS. The change from temperature control to the direct material control improves the production yield, increases the flexibility in the production and reduces the energy cost. Still there are more opportunities for this new technology, like the retained austenite measurement after the rapid cooling. Furthermore, the usage of higher X-ray energies extends the thickness range of the measurement and allows the phase fraction measurement in hot strip mills .

Naoki Shimoda, Toshiba Mitsubishi-Electric Industrial Systems Corporation, Japan

Co-Author:
Hiroyuki Imanari, Toshiba Mitsubishi-Electric Industrial Systems Corporation
Kazuhiro Ohara, Toshiba Mitsubishi-Electric Industrial Systems Corporation

Abstract:
The cutting-edge technologies of process control for the hot strip rolling mill are required to be developed and implemented to automation system. The accurate control contributes to stable rolling operation and higher quality of the products according to the demand of higher strength and lightweight material. We have responded to such demands by applying cutting-edge technologies of process model and control. In this paper, we introduce the recent application trend of process model and control technology contributing to hot strip rolling in so-called “conventional mill” line. We focus on technology of strip temperature model and control. A finite difference method (FDM) is applied to calculate the change of strip temperature by each time step and temperature distribution of a strip. The one-dimensional FDM split in thickness has been originally implemented to calculate surface and inside temperature of a strip separately. Nowadays it is also split in width direction to enable to estimate the temperature drop around strip side edge. It is flexible to be switched between one-dimensional and two-dimensional FDM individually for each rougher or finishing mill zone, and run out table cooling zone. The heat energy in a cross section of the strip is kept although the dimension of FDM is switched over. Combination of prediction of temperature by two-dimensional FDM model and the control of induction heating device contributes to accurate prediction and control of strip temperature especially at edge part. It may supply a high performance control system to produce uniform material properties of the strip along the horizontal and longitudinal directions. It is useful to monitor the temperature profile by FDM calculation even where a scan pyrometer is not equipped, and to study the rolling process conditions to get uniform material properties.

Kosei Tsuji, Primetals Technologies Japan, Japan

Co-Author:
Ichiro Maeno, Primetals Technologies Japan
Shinichi Yasunari, Primetals Technologies Japan
Takehiko Saito, Primetals Technologies Japan
Konrad Krimpelstaetter, Primetals Technologies Austria

Abstract:
"Actual mega trends like electro mobility, energy transition and urbanization require rapidly increasing amounts of non-grain oriented (NGO) and grain oriented (GO) electrical steels with improved magnetic properties for building high-efficient motors, generators, and transformers. Especially future electric cars will need more thin-gauge high-permeability NGO electrical steel for traction motors with low power losses to increase their cruising range. GO steels are the best choice for transformers, due to its outstanding magnetic properties in the rolling direction, and the demand will certainly rise with increasing electrification. In order to give newcomers, the possibility to enter the electrical steel market and to serve existing high-end producers with the best process technology, Primetals Technologies has developed and introduced many innovations to support a profitable production of NGO and GO electrical steel. This paper introduces best of the market technologies and references for the production of high-grade NGO electrical steels, like the advanced APL (Annealing Pickling Line) with new inline Silicon Reduction, the well-established 6-high cold rolling mill HYPER UC-MILL with additional features like edge-drop control (EDC), Minimum Quantity Lubrication (MQL) and Strip Temperature Guidance (STG). Further key technologies for GO production are described in the paper, like the new generation of 20-high mill HZ-MILL with advanced features to handle ultra-thin, hard, and brittle material grades while keeping highest geometrical tolerances and product quality."

Elmira Montazerozohour, Primetals Technologies Austria, Austria

Co-Author:
Bo Yang, Primetals Technologies Austria
Sergey Bragin, Primetals Technologies Austria
Carlo Piemonte, Primetals Technologies Austria
Andreas Jungbauer, Primetals Technologies Austria

Abstract:
With the limitations of conventional technologies, the development of electrical steel grades is rather challenging and requires lot of experience, such as ensuring uniform thermomechanical conditions along the length and width of the strip. Contrary, the endless operation of Arvedi ESP (Endless Strip Production) delivers uniformity naturally by its process design. Moreover, this environmentally friendly technology leaves zero-carbon emission with minimum energy consumption which fulfils the global trend of green steel production. The hot strip produced on the ESP line shows high quality and the necessary properties, as well as energy and cost saving benefits, for a wide range of electrical steels. This paper presents an analysis of the ESP process characteristics with their influence on the final properties and quality of electrical steels.

François Dumortier, John Cockerill, Belgium

Abstract:
Climate change is the biggest threat that humankind has ever faced. The decarbonization of transport is a crucial part of the solution to reducing greenhouse gas emissions and global warming. One of the most notable trends in this field is the considerable growth of the electrical vehicle market that is forecasted to become exponential in the coming years. Consequently, the production capacity of non-grain-oriented (NGO) electrical steel will have to increase at the same pace in order to fulfill the drastically and rapidly growing market needs. While addressing this challenge, electrical steel producers will also have to find ways to produce thinner strip and increase its silicon content to make vehicles lighter and considerably improve the efficiency of electric motors. To address the extremely difficult rolling of this type of advanced electrical steels, John Cockerill has developed a new 6-Hi reversing mill called: E-Qual® Mill. Its innovative design features an optimized work roll diameter specifically designed to avoid the roll flattening of thinner gauge electrical steel strip, all while providing the torque requirements for the first passes. Since this type of electrical steel is very brittle at ambient temperature, the E-Qual® Mill’s new design foresees the installation of an inductive heater on the pay-off reel pass line to avoid strip breakage at the first pass. Additionally, its upgraded cooling system allows for the highest degree of thickness homogeneity required to produce highly-performant electrical motors. The technical paper will present the new multi-functional mill design and the main technical characteristics of the mill.

Armin Büttgen, thyssenkrupp Steel Europe AG , Germany

Abstract:
New process for hot rolling of high-strength pipe steels A. Büttgen, A. Kern, C. Konrad, A. Latz, C. Straub thyssenkrupp Steel Europe, Duisburg Due to the ecological and economic situation worldwide and the resulting steadily increasing demand for pipelines, more and more efficiency of the hot strip manufacturing process to produce pipe steels is required. To achieve the demanding mechanical properties of modern pipe steels in terms of strength and resistance to brittle fracture, a very fine ferritic microstructure is crucial. So far, thermomechanical rolling with final rolling temperatures as low as 780 °C has been the method of choice. Unfortunately, this process reduces the plant performance due to noticeable delay times between roughing and finishing. Moreover, inhomogeneities become more pronounced along the strip, which deteriorates the performance of the product. To overcome this problem, a new rolling strategy for high-strength pipe steels was developed supported by numerical modelling of the microstructure and mechanical properties. In conjunction with a simultaneous adjustment of the cooling strategy with increased cooling rates, roughing and especially finishing can be carried out more gently. The resulting ferritic or ferritic-bainitic microstructure leads to at least a consistent product performance. This paper gives an overview on the characteristics of the new rolling strategy and presents first production results: The operational rolling results of pipe grade X70 show that the novel process leads to an increase in the performance of the hot strip mill compared to classical thermomechanical rolling. At the same time, the system load was significantly reduced and the product performance in terms of strength and resistance to brittle fracture was kept constant.

Mario Thome, SMS group, Germany

Co-Author:
Susanne Zeller, SMS group
Regine Ahrem, SMS group

Abstract:
The latest requests for ERW pipe mills were characterized by challenging conditions: the product range is more and more extended to pipes with extreme wall thickness and higher yield strength. At the same time, dimensional tolerances for pipes and profiles become stricter. Moreover, mill owners ask for technological support regarding easy and fast dimensional changeover in combination with traceability of process parameters and product quality. To comply with these demands machine and process design are transferred to a digital twin, which allows the designer to find the best mill configuration for revamped and new-planed mills. In combination with the mill automation the digital twin enables the operating personnel to find optimum settings in short time, taking in account induced deformation throughout the whole mill. This is big advantage for production, as the online model helps realizing the influence of the individual forming steps on the final quality. This saves valuable time and material, especially when dealing with a big variety of profile dimensions and pre-material conditions. In the first step towards the “digital twin” the complete pipe forming sequence was mapped as a parametric analytical calculation model, calibrated by FEA and practical experiences. Taking into account the interaction between stand usage, roll design and load limits, the model evaluates the optimum combination with regard to metal forming and economic aspects. Moreover, reliable initial setting values for the well-established “X-Pact® Quicksetting” system are calculated to accelerate commissioning new products or material grades. But also a process feedback is visualized online to indicate process limits and/or design limits. Up to now, the pre-forming section (lineal forming or breakdown forming) as well as forming section (fin-pass) and sizing/profiling have been added to the digital modelling approach. In future, a systematic process feedback enables a (self-)learning model to the point of a

Frank Padur, GMT mbH, Germany

Co-Author:
Kristin Helas, GMT mbH

Abstract:
Realistic material simulation is becoming increasingly worthwhile as part of simulation projects. If tolerances are to be calculated within a few hundredths or temperature variations within a few kelvins, the associated material data and models must also have a high degree of accuracy and match the conditions in the production process. The paper illustrates the influence of experimentally determined data, such as flow curves, temperature-dependent properties and CCT diagrams, and realistic material models, such as the microstructure and transformation model. Possibilities are shown to the user to apply the material knowledge for individual simulation projects, too. Various application examples illustrate the influence of accurate and validated material data sets on the simulation results of forming processes and heat treatments.

Nadine Schubert, Fraunhofer Institute for Machine Tools and Forming Technology, Germany

Co-Author:
Verena Kräusel, Fraunhofer Institute for Machine Tools and Forming Technology
Marco Wendler, Technische Universität Bergakademie Freiberg
Jürgen Steger, Fraunhofer Institute for Machine Tools and Forming Technology

Abstract:
Resource conservation and energy savings in component manufacture play a paramount role in the development of novel materials. Under this premise, the development of metastable austenitic steels with TRIP/TWIP properties is being strongly promoted. The results obtained on cast Cr-Mn-Ni steels in particular stand out here. Despite their heterogeneous and coarsely dendritic cast structure, these alloys are characterized by excellent cold formability comparable with wrought alloys. This is due to forming-induced plasticity effects and dislocation sliding. In order to exploit the full potential of these materials for forming technology, a technology is being developed at Fraunhofer IWU Chemnitz that makes it possible to shape cast semi-finished products into the desired form without any hot forming. The aim of the material-adapted forming processes is a high-strength and simultaneously tough edge zone as well as a tough core in the component. In this way, structural elements that can withstand high cyclic loads can be produced, which bring with them a high material-specific safety factor. As a result of the TRIP effect, potential crack propagation is counteracted. In addition to the targeted property design in the component, the energy-economical aspects should also be emphasized here. The use of cast semi-finished products shortens the process chain enormously. Otherwise usual heating and heat treatment steps are omitted, making it possible to achieve annual energy savings of ~1.5GJ per ton of manufactured components. Compared with the conventional process for producing solid formed parts from austenitic steel, the process chain to be developed represents a novel, energy- and resource-efficient process whose enormous potential for solid forming has not yet been exploited.

Koos van Putten , SMS group, Germany

Co-Author:
G. Winning, Friedr. Lohmann GmbH

Abstract:
Cogging is an incremental forming, open-die forging process that is used to produce rectangular, round or hexagonal semi-finished products with high demands in terms of mechanical properties and microstructure and is applied in many industrial fields, e.g. the tool manufacturing and automotive industries. An industrial cogging process for a 3.3-ton X38CrMoV5.1 tool steel ingot and the material properties of the ingot are comprehensively analyzed as part of the process validation, with an emphasis on studying the core deformation and gaining greater process knowledge. Material properties are obtained from a 2-ton X38CrMoV5.1 ingot. Cross-sectional boards at the foot (F), half-length (M), and head (H) plus one longitudinal board are sawn out of the ingot. Hot-working yield curves are determined at three different radial positions in the cross-sectional boards (F, H, M). The yield curves obtained for the core, filet, and edge at all length positions show negligible differences. Furthermore, the yield stress in the foot and head differs less than 6% from that at half-length. The hot-working yield strength is quite homogeneous throughout the ingot and does not significantly differ from the yield strength of the forged material. A metallographic analysis is conducted with the aid of the “HD scan” ultrasonic inspection system. The sawn boards are scanned and analyzed. A typical cast structure, free of shrink holes but with imperfections in the core, is observed. Traditional metallography provides a reference for the microstructure. In-depth process data are obtained from thermographic measurements and data logging during the cogging process on a 10-MN hydraulic open-die forging press. The FE-simulation of the 12-pass cogging process corresponds closely with the real process sequence. The calculated force shows only slight variations, and the final temperatures agree closely with the measurements. The quite homogeneous equivalent plastic strain in the core along the length of the block exceeds 1.5 throughout and

Martin Wolfgarten, SMS group, Germany

Co-Author:
Frederik Knauf, SMS group

Abstract:
Radial forging is an incremental forming process, which is mainly used for the production of bars with high requirements regarding the mechanical properties and the microstructure and is applied in almost all industry fields, e.g. in aerospace or medical industry. Nowadays, pass-schedule design in radial forging only considers the characteristics of the forging machine regarding the required forces and kinematic, while additional support, like decisive properties of the workpiece and process such as the resulting strain and temperature distribution is not provided. To realize a pass-schedule design considering the workpiece properties, SMS group exclusively developed new stand-alone models for strain and temperature in radial forging called ComForge® Property Predictor® and will be hosted within the forging technology suite ComForge®. The ComForge® Property predictor is capable to predict these decisive workpiece properties within seconds. By coupling these models with the established pass-schedule calculation software ComForge® Pass Schedule Calculator, for the first time process-design and optimization based on the final properties of the workpiece becomes possible. This not only allows optimizing pass-schedules in terms of quality and with regard to the workpiece properties, but also provides economic benefit for the machine operator by enabling shortening process chains, reduced personnel requirements and so reduction of safety margins within the process. The hereby-presented analysis proves that the hydraulic radial forging machine SMX in combination with advanced and unique technology tools offers significant benefit to produce high quality bars at optimum efficiency. In future, the technology suite ComForge® will be further developed by coupling ComForge® Property Predictor to a microstructure calculation to enable direct calculation and optimization of the resulting microstructure. Furthermore, coupling the models to the control system of radial forging machine will allow for an online analysis of temperature, strain and microstructure in radial forging.

Martin Scholles, SMS group, Germany

Co-Author:
Axel Rossbach, SMS group

Abstract:
Digitalization and Industry 4.0 will rock the forging industry now and in the years to come and will become Key for Major breakthroughs in regard of Optimization of Energy Consumption and Minimizing of Downtimes by Predictive Maintenance. Under the brand name iForge SMS group develops “easy to use” Tools and Applications for its closed-die forging customers to provide them with Hands-on Solutions that support them to stay ahead of the competition. The presentation will show you an example from the iForge digitalization program to show how Industry 4.0 can be implemented in practice.

Olivier Jaouen, Transvalor S.A., France

Abstract:
During the ingot casting, several kinds of particles can appear or be introduced in the cavity by the bucket. Lots of different reasons can explain this kind of foreigner bodies in the ingot. Some of them come from the liquid metal initially in the foundry bucket, the sand mold interaction, the riser or the slag interaction. These oxides particles, sand particles or other kind of inclusions could induce issue of metallurgical health of the ingot after cooling but also in the forward steps. It’s why lot of scientific projects are working on the slag/liquid metal interaction, entrapment of powder and all kind of defects and inclusions. Some embedded abrasive and inclusion generation models are already available in the state of the art and already used in our THERCAST® solution. We can also introduce different kind of particles (size, density) and follow their trajectories during the pouring. The main idea is to provide an appropriate software able to anticipate each inclusion generation and tracking at the end of the ingot casting process. Thanks to the global ‘End-to-End’ process simulation approach offered by Transvalor platform, it is possible to estimate the consequences during the next step of the metal transformation (forging, heat treatment). This presentation will show us how THERCAST® manage this kind of phenomena and the integrated physical models.