German Steel Research Articles

Energy intensity development of the German iron and steel industry between 1991 and 2007

The iron and steel sector is the largest industrial CO2 emitter and energy consumer in the world. Energy efficiency is key to reduce energy consumption and GHG emissions. To understand future developments of energy use in the steel sector, it is worthwhile to analyze energy efficiency developments over the past two decades. This paper analyses the development of the specific energy consumption (SEC) (measured as primary energy use per unit of product) in the German steel sector between 1991 and 2007. We found that the total SEC declined by 0.4%/year. Of this 75%, or 0.3%/year, is due to a structural change towards more electric arc furnaces (EAF). Energy efficiency improvement accounts for about 25% of the observed change in SEC, or 0.1%/year. Energy efficiency improvements are found, especially in rolling (1.4%/year). The net SEC of blast furnaces decreased due to increased top gas recovery by 0.2%/year per tonne iron. Improvements in other processes were very limited or non-existent. In basic oxygen furnaces (BOF) net SEC increased due to a 60% decrease in BOF gas recovery between 1993 and 2007. In EAF and sinter plants the SEC remained constant or, respectively, even increased by 9% between 1991 and 2007 per tonne sinter.

Analyzing energy and resource efficiency measures in the steel and zinc industry combining flowsheet simulation with a linear material and energy flow model

The German metal industry is confronted with an enforcing international competition, rising prices of energy and commodities, the increasing relevance of sustainable economy, political demands and incentives such as emission trading. To meet these challenges it is essential for companies to further improve resource and energy efficiency and to reduce CO 2 emissions. Usually, efforts concerning these objectives focus on new or improved single processes. In contrast, the presented approach extends the considerations to the inter-company perspective and considers multiple processes from ferrous and non-ferrous metals industry which are linked by material flows. Our considerations focus on residue flows in the iron and steel as well as the zinc industry. Steel production in integrated steelworks or electric steel plants involves the formation of large amounts of by-products, e.g. dusts, sludges or slags. These contain valuable substances such as iron or zinc and can be further processed by internal re-feeding or external recycling, e.g. by specialized companies, particularly Waelz kiln plants or the DK process. The latter produce zinc concentrates for the zinc industry. Changes in the modes of operation of one or more process can therefore affect the connected processes. We investigate strategies to further reduce landfilling and to efficiently allocate by-products to internal and external recycling options within the scope of the sketched network. We develop flowsheet models for representative processes within the regarded industries in Germany. With an Electric Arc Furnace (EAF), an integrated steelworks, two recycling companies, and a hydrometallurgical zinc plant the major processes of the German iron, steel and zinc industries are considered. We derive linear input-output functions for each of the processes by means of multiple linear regression analysis which we apply on results of systematically varied flowsheet simulation runs. These functions are used in a system of linear equations, forming a material and energy flow model of the regarded network. The model is applied to identify and assess strategies and measures to enhance resource and energy efficiency and to reduce climate relevant CO 2 emissions by scenario and sensitivity analyses. Thus, technical and economical barriers of inter-company measures can be overcome by identifying strategies which are technologically feasible and favorable with regard to the named objectives.

‘Immune system’ cyber-security for SCADA systems

Cyber-attack campaigns targeting Supervisory Control and Data Acquisition (SCADA) networks are increasing, and 2014 saw both the Energetic Bear campaign and the remote crippling of a German steel mill. When an analogy is made to the very effective human immune system, traditional cyber defences are clearly missing the key ability to adaptively detect and react to new and unseen threats. There are two viable methods for copying raw network traffic to an appliance without affecting the reliability of the operational process. Recent advances in computer hardware and machine learning techniques have made it possible for such an appliance to develop a deep understanding of normal network activity in real-time, and then highlight unusual behaviour. The three most prominent SCADA cyber campaigns of recent years – the steel mill, Energetic Bear, and Stuxnet – all produced activity that was clearly unusual for the networks they compromised. An immune system approach would have detected this and highlighted them for investigation. Cyber ‘immune systems’ deployed in real SCADA networks have identified a range of interesting behaviours not noted by the existing security stacks. This technology is already being used by major industrial companies such as Drax Power in the UK, to defend both their corporate and SCADA networks.

Integrated Sequencing and Scheduling in Coil Coating

We consider a complex planning problem in integrated steel production. A sequence of coils of sheet metal needs to be color coated in consecutive stages. Different coil geometries and changes of colors necessitate time-consuming setup work. In most coating stages one can choose between two parallel color tanks. This can either reduce the number of setups needed or enable setups concurrent with production. A production plan comprises the sequencing of coils and the scheduling of color tanks and setup work. The aim is to minimize the makespan for a given set of coils. We present an optimization model for this integrated sequencing and scheduling problem. A core component is a graph theoretical model for concurrent setup scheduling. It is instrumental for building a fast heuristic that is embedded into a genetic algorithm to solve the sequencing problem. The quality of our solutions is evaluated via an integer program based on a combinatorial relaxation, showing that our solutions are within 10% of the optimum. Our algorithm is implemented at Salzgitter Flachstahl GmbH, a major German steel producer. This has led to an average reduction in makespan by over 13% and has greatly exceeded expectations. This paper was accepted by Dimitris Bertsimas, optimization.

Management Insights

Management Insights

Application of a mathematical model to an intermediate- to long-term real-world steel production planning problem based on standard software

In this paper, a case study accomplished for the production planning of a German steel producer is presented. This includes the description of a lot-sizing problem and a related simple mathematical model formulated in order to meet the requirements for the mid- to long-term planning of the steel producer. Both the mathematical model and the representation of the results had to be implemented based on standard software products, namely the 'ILOG OPL-Studio' from IBM and the 'Advanced Planner and Optimizer' (APO) from SAP. The main focus is on the model and its implementation. That is, we show that a real-world problem can be solved by means of a simple mathematical model and standard software products reducing the individual programming effort. [Submitted 02 February 2009; Revised 06 November 2009, 16 February 2009; Accepted 23 February 2010]

Der „Napoleon des deutschen Aktienmarktes“ Hermann D. Krages und die Netzwerke des „rheinischen Kapitalismus“: Die Geschichte einer scheiternden Karriere

Abstract Taking as an example the career of the medium-sized entrepreneur Hermann D. Krages, who was attracting wide public attention by spectacular stock market transactions in the West German coal and steel industry during the 1950s and soon became a predominantly yield oriented financial investor, this paper discusses, why an economically successful outsider like Krages was not able to establish himself as a respected member of the business elites’ networks within Rhenish Capitalism. For this purpose, the analysis focuses on a heavy conflict between Hermann Krages and Dresdner Bank AG between 1962 and 1966. As the article shows, Krages can be interpreted as an early, extremely stubborn and at the same time completely inopportune pioneer of shareholder value thinking. His initially so promising career finally failed, because his mentality and his business strategies, based on credit financed stockmarket speculations, did not at all correspond to the notion of steady and responsible business of the overwhelming majority of his contemporaries.

Steel research int. 8/2010

Cover Photo: Roll‐off container made of high‐strength and wear‐resistant steel sheets; this new light‐weight construction enables weight reduction by 45% compared to conventional steel. 2009 Steel Innovation Prize by the German Steel Industry Association. Copy by courtesy of Sirch GmbH & Co. KG, Kaufbeuren, and Stahl‐Informations‐Zentrum, Düsseldorf.

CFD Benchmark for a Single Strand Tundish (Part II)

AbstractIn a comparative benchmark, nine participants of the German Steel Institute VDEh working group “Fluid Mechanics and Fluid Simulation” studied the melt flow in a 16‐t single‐strand tundish. Starting with a steady‐state simulation of the melt flow, the transient flow behaviour was simulated for an idealized ladle change involving a sudden jump in temperature and concentration. In addition, the separation of non‐metallic particles to the melt surface was examined. No guidelines and limitations were made regarding the simulation strategy. The predicted flow profiles, temperature and concentration distributions coincide with each other within a good approximation. Systematic differences in the transient temperature and turbulence fields are explained by the selection of the boundary condition at the free surface. All CFD programs reproduce the fundamental flow structure with a good degree of accuracy. The separation rate for non‐metallic particles calculated on the basis of the Lagrange Method are greater than would be expected according to theory and measurement results obtained on the water model.

Determination of Hydrogen in Steel by Thermal Desorption Mass Spectrometry

AbstractHydrogen embrittlement has been observed since high‐strength steels have been produced in the nineteen thirties 1,2. Several different analytical methods have been developed to quantify the total and diffusible hydrogen in steel, but many aspects of hydrogen determination are still to be explored. Purely quantitative determination of hydrogen is not sufficient to fully characterize the steel regarding its resistance against embrittlement.Thermal Desorption Mass Spectrometry (TDMS) allows the investigation of hydrogen absorption and desorption mechanisms to characterize hydrogen traps in different kinds of steel microstructures. This provides valuable information for the development of new materials with a higher resistance against hydrogen embrittlement. Additionally, TDMS allows the quantitative determination of very small concentrations of hydrogen (<0.1 µg/g). Such low detection limits cannot be reached with other methods. Due to time‐consuming analysis and a rather complex construction, TDMS is usually not applied for hydrogen determination in German steel mills. The present work describes the development of a thermal desorption spectrometer at ThyssenKrupp Steel Europe AG by adapting a compact quadrupole mass spectrometer to a commercially available hot solid extraction analyzer, which has proven to be a simple and efficient solution for the determination of diffusible hydrogen in steel.

Steel research int. 6/2010

Cover Photo: Gas turbine of a 530 MW gas and steam power station, working at 3000 r.p.m. and 1500°C, resulting in an efficiency of 60%. This performance is enabled by heat resistant steels like 16Mo3, 27NiCrMoV15‐6 or X12CrMoWVNbN10‐1‐1. 2009 Steel Innovation Prize by the German Steel Industry Association. Copy by courtesy of Siemens AG and Stahl‐Informations‐Zentrum.

Steel research int. 5/2010

Cover Photo: Light‐weight countershaft in an in‐line 4‐cylinder engine. This forged steel countershaft of ball bearing type replaces cast countershafts with plain bearings, allowing delicate shapes and thus reducing weight by one third. 2009 Steel Innovation Prize by the German Steel Industry Association. Copy by courtesy of Schaeffler KG, Herzogenaurach, and Hirschvogel Umformtechnik GmbH, Denklingen, and Stahl‐Informations‐Zentrum, Düsseldorf.

Steel research int. 4/2010

Cover Photo: Stainless steel foil of 0.025 mm thickness as substrate for organic light emitting diodes (OLED) or organic solar cells. The stainless steel provides the high corrosion resistance, high strength and stiffness as well as weather protection and cooling which are required for cost effeicient applications of OLEDs or solar cells. 2009 Steel Innovation Prize by the German Steel Industry Association. Copy by courtesy of Technische Universität Braunschweig, Institut für Hochfrequenztechnik, and Stahl‐Informations‐Zentrum, Düsseldorf.

Steel research int. 3/2010

Cover Photo: Sheet Cast Disc: light‐weight brake disc in composite design; its friction ring is still made of cast iron but the disc pot is an insert of a high‐strength steel sheet. This steel design ensures not only reduction in weight but also reduction in thermal distortion, which results in improved driving comfort and fuel consumption. 2009 Steel Innovation Prize by the German Steel Industry Association. Copy by courtesy of Sheet Cast Technologies GmbH, München, and Stahl‐Informations‐Zentrum, Düsseldorf.

Steel research int. 1/2010

The cover shows a hook and loop closure made of temperature‐resistant stainless steel, consisting of a 0.2 mm thick hook strip and a 0.2 mm thick punched or stamped pile strip of stainless spring steel. 2009 Steel Innovation Prize by the German Steel Industry Association. (Copy by courtesy of Reinz‐Dichtungs‐GmbH, Neu‐Ulm, and Stahl‐informations‐Zentrum, Düsseldorf)

Zwischen Mitbestimmungs- und Europapolitik: Die IG Metall und die Anfänge der europäischen Integration

In contrast to the German federation of trade unions (DGB) and the union of mine-workers (IG Bergbau), the union of metal-workers (IG Metall) was rather sceptical about the Schuman Plan in the early 1950s. In particular, fears were expressed that the codetermination, just achieved in 1947, would be undermined and that the German iron and steel industry would suffer disadvantages against the French industry. Considering this point of view the union of metal-workers was isolated within the trade union movement. Hence, the metal-workers finally accepted the ratification of the treaty of the European Coal and Steel Community and shared the arrangement while continuing to pursue their objectives.

Determinants of structural change and innovation in the German steel industry an empirical investigation

In the last 30 years, specific primary energy use in the German steel industry has decreased by about 30%. This decrease can be attributed to both structural changes in the steel industry (from basic oxygen steel to electric arc furnace steel) and to the improved energy efficiency of new technologies within these technological paradigms. In this paper, the relevance of various determinants for the diffusion of electric arc furnace steel (structural change) and for the energy-use of new technologies in the German steel industry sector is assessed econometrically. The empirical findings support the hypotheses that the diffusion of electric arc furnace steel is accelerated by energy and material input prices and dampened by path dependencies. The findings further suggest that the energy performance of new technologies is affected by energy and material input prices, by expenditures for research and development, and – for basic oxygen steel – also by industry concentration.

05/02795 Endogenous technological change and emissions: the case of the German steel industry

05/02795 Endogenous technological change and emissions: the case of the German steel industry

Screening of primordial and artificial radionuclides in German steel by low-level gamma-ray spectrometry in an underground laboratory

Screening of primordial and artificial radionuclides in German steel by low-level gamma-ray spectrometry in an underground laboratory

Screening of primordial and artificial radionuclides in German steel by low-level gamma-ray spectrometry in an underground laboratory

Main sources of radionuclides in steel in nuclear decommissioning are the unintentional melting of orphan sources and scrap. This paper presents data about the activity of γ-emitters in German steels obtained by low-level γ -ray spectrometry in an underground laboratory. The 60Co activity exceeds only 2% of the 215 analyzed samples with a detection limit of 4.4 . 10-5 Bq . g-1. Even the maximum measured 60Co activity of 2.5 . 10-4 Bq . g-1 is a factor of 400 lower than the clearance level. The determination of the detector efficiency is also described for these unusual samples using Monte Carlo calculations.