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Schaffnit P.,Salzgitter Mannesmann Forschung GmbH | Stallybrass C.,Salzgitter Mannesmann Forschung GmbH | Konrad J.,Salzgitter Mannesmann Forschung GmbH | Konrad J.,KHS Plasmax GmbH | And 2 more authors.
Calphad: Computer Coupling of Phase Diagrams and Thermochemistry | Year: 2015

Modelling of solidification is of industrial and theoretical relevance. An accurate estimation of the actual liquidus and solidus temperatures leads to significant improvements in quality and efficiency of steel production as well as substantially reduces the energy consumption and the ecological footprint. An optimisation of the Scheil-Gulliver model for solidification with the aim to predict the solidus temperature of steels (Scheil-Gulliver for Steel, SGS) is presented. The SGS model allows an easy and accurate simulation of the solidification interval using software based on the CALPHAD approach. Based only on the steel composition, the model consistently choses between full equilibrium for ferrite and partial redistribution of alloying elements (Scheil-Gulliver approach) for austenite. The predictions of the model were compared to differential thermal analysis (DTA) measurements of industrial heats, which represent a wide range of compositions. The agreement of the data calculated with the SGS model with the values measured by DTA represents an improvement compared to existing models. © 2015 Elsevier Ltd. All rights reserved. Source

Jahn A.,Vallourec and Mannesmann Deutschland GmbH | Steinhoff K.-P.,Huttenwerke Krupp Mannesmann GmbH | Dubberstein T.,TU Bergakademie Freiberg | Franke P.,Karlsruhe Institute of Technology | And 9 more authors.
Steel Research International | Year: 2014

In the present work the influence of phosphor on the flowability, the effect on the infiltration of ZrO2 open foam ceramics and the martensite formation as well as the resulting mechanical properties of high alloyed CrMnNi as-cast steels is studied. Additionally, the effect of phosphor on surface tension is investigated. The study is performed using thermodynamic calculations, static tensile tests, notch-bar impact tests, optical light microscopy, scanning electron microscopy, energy dispersive X-ray analysis, electron backscatter diffraction, and the magnetic scale for the detection of ferromagnetic phase fractions. Maximum bubble pressure method is used to measure the surface tension of the liquid steel. The martensite phase fraction is not significantly influenced with increasing phosphor content. The flowability and the quality of the infiltration of open foam ceramics are improved with increasing phosphor contents. The investigated specimens show an increasing yield and an ultimate tensile strength with higher phosphor contents. The uniform and the fracture elongation as well as the notch impact resistance remain at high values. Moreover, an increase in phosphor content did not significantly change the surface tension of the investigated CrMnNi alloys. The influence of increasing phosphor content on the flowability, the effect on the infiltration of ZrO 2 open foam ceramics, the martensite formation as well as the resulting mechanical properties and the surface tension of high alloyed CrMnNi as-cast steels are studied. The elongation properties are not influenced by increasing phosphor content. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Babich A.,RWTH Aachen | Senk D.,RWTH Aachen | Knepper M.,Huttenwerke Krupp Mannesmann GmbH | Benkert S.,ArcelorMittal
Ironmaking and Steelmaking | Year: 2016

Operation of several blast furnaces proved that waste plastic (WP) injection makes recycling of industrial and municipal organic wastes and coke saving possible. However, the extent and reaction kinetics of plastic conversion are hardly explored yet. Therefore, a comprehensive study on WP characteristics and conversion behaviour under simulated raceway, bird's nest and shaft conditions, as well as on its interaction with coke, has been undertaken. Numerous analytical, laboratory and pilot facilities have been used. has shown that despite favourable chemistry, it is hardly possible to reach a high conversion degree of plastics under the raceway conditions. Consumption of unburned residues in coke bed and in shaft is possible. The effect of this phenomenon on coke reactivity has to be considered as well. © 2016 Institute of Materials, Minerals and Mining. Source

Folz F.-J.,Dr. Ing. Folz Gleitlagertechnik GmbH | Kleinjan O.,Asku Scholten GmbH | Burchartz B.,Huttenwerke Krupp Mannesmann GmbH | Hueske K.-D.,Salzgitter Flachstahl GmbH
Stahl und Eisen | Year: 2014

Even without lubrication a newly developed heat-treatable / hardened manganese steel tribological pairing will as a trunnion mounting on heavy duty steel and pig iron casting ladles achieve a service life of at least 10 to 12 years, whereas the average service life of conventional tribological pairings made of ferritic steel and miscellaneous copper alloys or other steel matrices is only 0.4 to 0.8 years despite intensive periodic lubrication. The new pairing makes it possible to significantly reduce the lubrication or render it unnecessary. The article describes operating results from the re-equipment of Hüttenwerke Krupp Mannesmann GmbH in 1999/2000 with 26 steel and mixing ladles of the latest generation and apayload of 375 t. At the steelworks of Salzgitter Flachstahl in Germany the bearing arrangement was adapted to the existing 250-t vessels. The findings from theory and experiment are confirmed by the many years' experience available today on the whole. In addition to significant savings in costs and resources, the new steel friction bearing leads to a considerable environmental protection. The operational reliability will also undergo a sustainable increase. Source

Bartusch H.,VDEh Betriebsforschungsinstitut GmbH | Hauck T.,VDEh Betriebsforschungsinstitut GmbH | Grabietz H.-G.,Huttenwerke Krupp Mannesmann GmbH
Stahl und Eisen | Year: 2014

Chlorine compounds in the top gas lead to corrosion at pipes, hot stoves and tuyères of the blast furnace. However chlorine issues in the blast furnace have been only little investigated. On base of results from special measurements, mass balance and equilibrium calculations carried out at Hüttenwerke Krupp Mannesmann, this contribution discusses main chlorine inputs and the behaviour of chlorine within the blast furnace process. Suggestions for the handling of chlorine in the process are reflected. Source

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