ThyssenKrupp Steel Research Articles

Experimental Validation of Stationary and Transient Models of a Methanol Demonstration Plant

AbstractThe system integration of cross‐industrial networks in the Carbon2Chem® project relies on numerical simulations. Hence, this study validates the methanol synthesis loop models vs. the measurements from a demonstration plant, focusing on the thermodynamic, kinetic, and dynamic aspects. The plant can produce up to 500 L per week of methanol from real blast furnace gases of the thyssenkrupp steel plant in Duisburg. Despite its small size, it comprises a recycle gas loop and an original reactor tube of 6 m in length. After validation, the simulation models are used to analyze the dynamic operation limits of the plant, and they are transferred to the model of an industrial size to analyze the operation of cross‐industrial networks with volatile boundary conditions.

Assessment of the Tribological Properties of the Steel/Polymer/Steel Sandwich Material LITECOR

The article presents the results of tribological investigations into the steel/polymer/steel sandwich material LITECOR® developed by ThyssenKrupp Steel Europe for applications in the automotive industry. Friction tests were carried out by means of a strip drawing test with the use of a special tribotester mounted on a uniaxial tensile test machine. The influence of sheet deformation on the value of the coefficient of friction (COF) was considered. For this purpose, the samples were subjected to a pre-deformation of 4%, 8% and 12%. Friction tests were carried out with different force values and under different friction conditions, i.e., in dry friction conditions and lubrication of the sheet surface with L-AN 46 machine oil. The highest values of COF were observed for as-received sheets. In contrast, apart from the friction process under the conditions of the lowest force analysed, the lowest value of the COF was observed for pre-strained sheets with a deformation of 12%. The lubrication efficiency of the pre-strained strip specimens with ε = 4% was between 10.5% and 16.3%, with a trend of increasing lubrication efficiency with increasing force. For pre-strained sheets with deformation ε = 12%, there was a trend of decreasing effectiveness from 14.9% to 9.03% with an increase in force.

Carbon footprint of scenarios towards climate-neutral steel according to ISO 14067

Within this paper, new findings of the potential of four considered intermediate solutions towards a primary climate-neutral steel production are reported. (1) Injection of natural gas into a blast furnace, (2) injection of hydrogen into a blast furnace, (3) natural gas-based direct reduction with subsequent input of the hot briquetted iron (HBI) in a blast furnace, and (4) hydrogen-based direct reduction with subsequent input of the hot briquetted iron in a blast furnace.The current study is a carbon footprint assessment applied to the product hot-rolled coil (HRC) according to the ISO norm 14067:2019. A cradle to gate approach is used including the production of raw materials to the production of hot-rolled coil. To define a reference point, a carbon footprint of hot-rolled coil produced via a typical blast furnace – basic oxygen furnace (BF-BOF) route is presented. The basic data set is based on primary data from the integrated site of thyssenkrupp Steel Europe AG (tkSE), year 2018. Within a novel approach, this base line is enhanced by integrating metallurgical models from the literature. Thereby all changes of the complex material and energy supply chain of an integrated site and of the upstream chain are reported. The carbon footprint of each process unit is presented in detail so that optimization potentials are identified, which impacts are analysed within a sensitivity analysis. A holistic comparison of using hydrogen in a blast furnace to using hydrogen in a direct reduction plant is presented and delivers important findings. This can help steel producers to maximize the efficiency of hydrogen use.Since the focus of this paper lies on the comparison of steel production routes and the assessments for all considered scenarios are based on the same methodologies and databases the sensitivity of made assumptions on the deltas between these scenarios is much weakened than the sensitivity of absolute values. That's one of the reasons why, the conclusions of this paper, which are referred to the plant of tkSE, can be transferred to other production sites, as well. The presented results can help decision-makers to know the potentials of possible intermediate solutions towards a climate-neutral steel production and how the potentials can be maximized.The carbon footprint of the product hot-rolled coil is 2.1 t CO2eq/tHRC following the recycled content approach and 0.82 t CO2eq/tHRC following the end-of-life recycling approach. The reduction potential for the carbon footprint is about 4 % for injecting natural gas into a blast furnace and about 9 % for injecting hydrogen into a blast furnace. The hydrogen is produced via electrolysis driven by a renewable German energy mix, year 2018. Using hot briquetted iron (HBI) within a blast furnace leads to a reduction potential between 5 % and 12 % for natural gas based-HBI and between 10 % and 17 % for H2-based HBI. The reduction potential strongly depends on the iron feedstock, which is replaced by the hot briquetted iron. Between 4.5 and 7.0 kg CO2eq/kg H2 are avoided by injecting hydrogen into a blast furnace, and about 5.4 kg CO2eq/kg H2 are prevented if the hydrogen is injected into a direct reduction plant.

Dimensionally accurate parts made of high-strength steels - compressive stress superposition instead of tool compensation

As a result of the increasing use of high-strength and ultra-high-strength steels as part of the automobile lightweight construction strategies, the issue of dimensional accuracy of component structures is increasingly becoming the focus of toolmakers, pressed part suppliers and automobile manufacturers. In particular, the modern dual-phase steels with strengths of over 800 MPa possess-depending on the respective component geometry and the forming process employed-a pronounced springback behaviour. The compensation measures commonly used so far are more and more reaching their limits, which in turn impairs the process ability of these grades in the cold forming process. The smartform® process developed by thyssenkrupp Steel Europe AG allows the cold forming of high-strength steels with high repeatable accuracy, which significantly expands their areas of application. In this process, the tensile stresses from the forming operation causing the springback of the part are eliminated by compressive stress-superposition, which leads to high dimensional stability. There is almost no need to adapt the tool surfaces to achieve a dimensionally accurate part. How close the formed component comes to the dimensional tolerances specified by the end user is usually determined within the framework of numerical method development. In this context, the result of a springback simulation depends on various parameters. The description of the material behaviour is of major importance. Moreover, the use of extended material models can have an influence on the predictive accuracy and reduce the deviations between simulation and real material behaviour. It remains to be identified to what extent the increase in accuracy is proportional to the modelling effort.

Life Cycle Assessment of an Integrated Steel Mill Using Primary Manufacturing Data: Actual Environmental Profile

The current dependency on steel within modern society causes major environmental pollution, a result of the product’s life cycle phases. Unfortunately, very little data regarding single steel production processes have been found in literature. Therefore, a detailed analysis of impacts categorized in terms of relevance cannot be conducted. In this study, a complete life cycle assessment of steel production in an integrated German steel plant of thyssenkrupp Steel Europe AG, including an assessment of emissions from the blast furnace, the basic oxygen furnace, and casting rolling, is carried out. The functional unit is set to 1 kg hot-rolled coil, and the system boundaries are defined as cradle-to-gate. This study models the individual process steps and the resulting emitters using the software GaBi. Total emissions could be distributed into direct, upstream, and by-product emissions, where the biggest impacts in terms of direct emissions from single processes are from the power plant (48% global warming potential (GWP)), the blast furnace (22% GWP), and the sinter plant (79% photochemical ozone creation potential (POCP)). The summarized upstream processes have the largest share in the impact categories acidification potential (AP; 69%) and abiotic depletion potential fossil (ADPf; 110%). The results, including data verification, furthermore show the future significance of the supply chain in the necessary reduction that could be achieved.

Hot stamping steel grades with increased tensile strength and ductility - MBW-K 1900, tribond 1200 and tribond 1400

The use of hot formed 22MnB5 steel with an aluminium-silicon (AS) coating is well established for high strength automotive parts to combine weight reduction and passenger safety. Recent developments aim to increase the material strength for further weight saving and to improve the ductility. Especially an improved ductility makes hot formed parts suitable for additional applications, such as parts with higher energy absorption or even axially loaded parts. thyssenkrupp Steel Europe AG has developed new hot stamping grades. With an increased strength of about 1900 MPa, the MBW-K 1900 allows the application of even lighter parts compared to 22MnB5. Due to the increased strength level, delayed fracture has to be evaluated. Furthermore, the recommended parameters for processing MBW-K 1900 are regarded.A high crash performance of a material implies a high strength, while the material still shows no cracking during folding or heavy bending of the automotive part. This is the basis for the development of tribond 1200 and tribond 1400. As a new concept for hot stamping, tribond 1200/1400 are composite materials, which bond two outer layers of a ductile 500 MPa steel grade with a high strength 1500 MPa steel core layer. Both grades are already well known as monolithic steels MBW 500 and MBW 1500 for hot stamping. An aluminium-silicon coating allows tribond 1200/1400 to be processed in the same way as AS coated 22MnB5. Nevertheless tribond 1200/1400 show a reduced susceptibility to hydrogen embrittlement in the 4-point bending test compared to 22MnB5. By their improved crash behaviour, tribond 1200/1400 enable the manufacturing of more kinds of hot formed parts such as longitudinal beams. An advanced simulation method takes the composite structure of tribond 1200/1400 into account to evaluate the crash behaviour.

CP-K 900Y 1180T

Abstract CP-K 900Y 1180T is one of a family of omplex-phase steels, CP-W and CP-K, that offer very high strengths and yield points. They are particularly suitable for weight-saving production of cold-formed, crash-relevant automotive components such as side impact intrusion beams, B-pillar reinforcements,profiles, cross members, body reinforcements, bumper bars, and chassis parts. This datasheet provides information on composition and tensile properties. It also includes information on forming and heat treating. Filing Code: SA-849. Producer or source: ThyssenKrupp Steel Europe AG.

CP-K 570Y780T

Abstract CP-K 570Y780T is one of a family of complex-phase steels, CP-W and CP-K, that offer very high strengths and yield points. They are particularly suitable for weight-saving production of cold-formed, crash-relevant automotive components such as side impact intrusion beams, B-pillar reinforcements,profiles, cross members, body reinforcements, bumper bars, and chassis parts. This datasheet provides information on composition, hardness, and tensile properties. It also includes information on heat treating. Filing Code: SA-848. Producer or source: ThyssenKrupp Steel Europe AG.

CP-W 1000

Abstract CP-W 1000 is one of a family of omplex-phase steels, CP-W and CP-K, that offer very high strengths and yield points. They are particularly suitable for weight-saving production of cold-formed, crash-relevant automotive components such as side impact intrusion beams, B-pillar reinforcements,profiles, cross members, body reinforcements, bumper bars, and chassis parts. This datasheet provides information on composition and tensile properties. It also includes information on heat treating and joining. Filing Code: SA-845. Producer or source: ThyssenKrupp Steel Europe AG.

CP-W 800

Abstract CP-W 800 is one of a family of complex-phase steels, CP-W and CP-K, that offer very high strengths and yield points. They are particularly suitable for weight-saving production of cold-formed, crash-relevant automotive components such as side impact intrusion beams, B-pillar reinforcements,profiles, cross members, body reinforcements, bumper bars, and chassis parts. This datasheet provides information on composition and tensile properties. It also includes information on forming, heat treating, and joining. Filing Code: SA-843. Producer or source: ThyssenKrupp Steel Europe AG.

CP-W 660

Abstract CP-W 660 is one of a family of omplex-phase steels, CP-W and CP-K, that offer very high strengths and yield points. They are particularly suitable for weight-saving production of cold-formed, crash-relevant automotive components such as side impact intrusion beams, B-pillar reinforcements,profiles, cross members, body reinforcements, bumper bars, and chassis parts. This datasheet provides information on composition and tensile properties. It also includes information on forming, heat treating, and joining. Filing Code: SA-841. Producer or source: ThyssenKrupp Steel Europe AG.

MHZ 500

Abstract MHZ 500 (mininum yield strength of 500 MPa) is one of a series of microalloyed cold forming steels. The high-strength properties result from precipitation hardening thanks to finely-dispersed carbonitrides and a fine-grained microstructure. Even very small amounts of the elements titanium and/or niobium in the region of 0.01% result in a significant increase in the yield point and tensile strength. This datasheet provides information on composition and tensile properties as well as fatigue. It also includes information on forming and joining. Filing Code: SA-837. Producer or source: ThyssenKrupp Steel Europe AG.

XAR 400W

Abstract XAR 400W is a special wear-resistant structural steel as thick plate that is water quenched and tempered. These wear-resistant materials last at least five times longer than conventional steels due to their extreme hardness and toughness. It is heat resistant up to 400 deg C. This datasheet provides information on composition and physical properties. It also includes information on wear resistance as well as forming, heat treating, machining, and joining. Filing Code: SA-836. Producer or source: ThyssenKrupp Steel Europe AG.

MHZ 460

Abstract MHZ 460 (mininum yield strength of 460 MPa) is one of a series of microalloyed cold forming steels. The high-strength properties result from precipitation hardening thanks to finely-dispersed carbonitrides and a fine-grained microstructure. Even very small amounts of the elements titanium and/or niobium in the region of 0.01% result in a significant increase in the yield point and tensile strength. This datasheet provides information on composition and tensile properties as well as fatigue. It also includes information on forming and joining. Filing Code: SA-835. Producer or source: ThyssenKrupp Steel Europe AG.

MHZ 420

Abstract MHZ 420 (mininum yield strength of 420 MPa) is one of a series of microalloyed cold forming steels. The high-strength properties result from precipitation hardening thanks to finely-dispersed carbonitrides and a fine-grained microstructure. Even very small amounts of the elements titanium and/or niobium in the region of 0.01% result in a significant increase in the yield point and tensile strength. This datasheet provides information on composition and tensile properties as well as fatigue. It also includes information on forming and joining. Filing Code: SA-831. Producer or source: ThyssenKrupp Steel Europe AG.

XAR 450 Premium

Abstract XAR 450 Premium is a special wear-resistant structural steel as thick plate that is water quenched and tempered. These wear resistant materials last at least five times longer than conventional steels due to their extreme hardness and toughness. This datasheet provides information on composition, microstructure, hardness, and tensile properties. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: SA-833. Producer or source: ThyssenKrupp Steel Europe AG.

XAR 400 Premium

Abstract XAR 400 Premium is a special wear-resistant structural steel as thick plate that is water quenched and tempered. These wear-resistant materials last at least five times longer than conventional steels due to their extreme hardness and toughness. This datasheet provides information on composition and tensile properties. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: SA-830. Producer or source: ThyssenKrupp Steel Europe AG.

MHZ 380

Abstract MHZ 380 (mininum yield strength of 380 MPa) is one of a series of microalloyed cold forming steels. The high-strength properties result from precipitation hardening thanks to finely-dispersed carbonitrides and a fine-grained microstructure. Even very small amounts of the elements titanium and/or niobium in the region of 0.01% result in a significant increase in the yield point and tensile strength. This datasheet provides information on composition and tensile properties as well as fatigue. It also includes information on forming and joining. Filing Code: SA-828. Producer or source: ThyssenKrupp Steel Europe AG.

X-COR

Abstract This alloy is a special steel grade for pressure vessels with HIC (hydrogen-induced cracking) resistance. This datasheet provides information on composition. It also includes information on corrosion resistance as well as forming and joining. Filing Code: SA-825. Producer or source: ThyssenKrupp Steel Europe AG.

MHZ 340

Abstract MHZ 340 (mininum yield strength of 340 MPa) is one of a series of microalloyed cold forming steels. This datasheet provides information on composition and tensile properties as well as fatigue. It also includes information on forming and joining. Filing Code: SA-824. Producer or source: ThyssenKrupp Steel Europe AG.