From front to back: Continuous online measurement of material properties for optimisation of the furnace model in the SEGAL hot-dip galvanising line

Today's advances in flat steel production are predominantly driven by the significant increase in the demand for high-strength steels (e.g. AHSS: Advanced High Strength Steels). Furthermore, the high quality standards of the automotive market have resulted in significantly more stringent requirements for steel manufacturers.

In this context, EMG started collaborating on a development project with the EMG IMPOC system on the Segal hot-dip galvanising line in Liege/Belgium in 2013 in collaboration with partners the SMS group, Drever and Tata Steel. The objective of this project is, on the one hand, to improve (homogenise) the material qualities of higher-strength materials, such as dual-phase steels, while on the other hand increasing productivity and simultaneously reducing energy costs.

An IMPOC system has been installed near the outlet of the continuous annealing furnace of the Segal hot-dip galvanising line since as early as 2014. The SMS group and Drever, the manufacturer of the continuous annealing furnace, continuously adapted the parameters of the mathematical furnace model by using the measuring results from the IMPOC system. The resulting adjustments made to the operation of the furnace with regard to temperatures, cooling rates and speeds in the various sections of the furnace, not only led to an increase in the quality of the material produced - IMPOC is used as an additional system for material release - but also to an overall increase in production throughput by 15%.

This outstanding result naturally instilled a desire for more. Another IMPOC system is currently being tested at a location upstream of the continuous furnace. The objective here is to determine faster and more favourable parameter settings for the mathematical model and thus for the continuous annealing process. A difficulty facing this line is caused by the input material. Due to the upstream manufacturing process, the structures in the material are irregular rather than homogenous. If these inhomogeneities are known - therefore enabling use of the IMPOC system upstream of the furnace - the mathematical furnace models can take these into account. As a result, there is potential to enhance the quality and yield even further.

Continuous measurement of material properties with the EMG IMPOC system upstream and downstream of the annealing furnace at the Segal hot-dip galvanising line (principle diagram)

However, the Segal hot-dip galvanising line is not an isolated case. The coupling of the microstructure model for the annealing process (SMS group), the furnace model (Drever) and the IMPOC system was also implemented in the spring of 2017 for the Universal hot-dip galvanising and annealing line, which the SMS group is currently constructing for Big River Steel in the USA. This so-called iFurnace approach is becoming established and is set to ensure optimal quality results as well as high production throughput.

Conclusion: The continuous online measurement of material properties by EMG's IMPOC system, combined with the physical and mathematical models for the annealing process and furnace operation (iFurnace approach), provides the ideal prerequisites for high production throughput while simultaneously ensuring high product quality.

About EMG Automation

EMG Automation GmbH, a company of the elexis group, belongs to the leading suppliers, due to its technological competence in the core area of regulation systems as well as quality assurance in automated manufacturing processes. Fields of application are fast running continuous production processes in the metal and especially in the steel industry. The product portfolio includes, besides quality assurance systems, strip running regulators. The EMG group runs its own factories as well as sales and service offices in Wenden/Germany, Oschersleben/Germany, Bielefeld/Germany, Rengsdorf/Germany, Elmhurst/USA, Belo Horizonte/Brazil, Osaka/Japan, Baroda/India, Beijing/China, Shanghai/China as well as Madison/USA.

Based on EMG Automation GmbH information