bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fields of activity of the Institute of Energy Process Technology of the Technical University of Clausthal
Authors: Jeschar Rudolf , Pötke Wolfgang , Scholz Reinhard 
Published: December 2016

The report presented here is a description of the main fields of activity of the Institute of Energy Process Technology of the Technical University of Clausthal. The institute investigates both fundamental problems and those arising in the industrial practice in the field of high‐temperature technology for the areas of heat and mass transfer, thermodynamics, flow technology, combustion and chemical kinetics.The production process in a metallurgical plant, including the areas of blast furnace, steel work, continuous casting and heating furnaces in the rolling mill as well as heat treatment plants, is taken as a basis to expound on the current activities of the institute in greater detail. This volume informs on the results of investigations concerning the areas of blast furnace, steelwork and continuous casting. The following volume will contain the themes from the remaining two areas of production mentioned above, which will be supplemented by investigations into the minimization of the energy consumption in continuous furnaces for the ceramics, lime and cement industries and into the low‐pollutant combustion of difficult fuels.
Texture analysis by electron diffraction
Authors: Schwarzer Robert A. 
Published: December 2016

Electron diffraction methods for the determination of individual grain orientations and selected area diffraction (SAD) pole figures are briefly reviewed. The standard techniques of orientation determination grain‐by‐grain are the interpretation of selected‐area electron spot and microbeam Kikuchi diffraction patterns with a transmission electron microscope (TEM). Electron‐transparent thin samples are required. Specimen areas smaller than 500 nm or 10 nm in diameter, respectively, can be studied. Alternatively, selected area pole figures can be measured on a TEM. This technique is similar to the conventional transmission x‐ray method. The orientations of grains in a bulk sample are obtained with a scanning electron microscope (SEM) from back‐reflection Kikuchi patterns (i.e. electron backscattering patterns) or from channelling patterns. Spatial resolution is approximately 1 μn or 5 μm, respectively.Individual grain orientation and pole figure measurements can be performed on‐line by interfacing the electron microscope with a computer. Outstanding advantages of texture measurement by electron microscopy over x‐ray and neutron diffraction are the ability to image the microstructure of the sampled area which complements texture measurement, and the high spatial resolution in diffraction and imaging modes. Experimental results of individual grain orientation measurement may be represented by inverse pole figures, orientation distribution functions, and misorientation distribution functions.
Einfluß des Sauerstoffs auf die Ausbildung von Aluminiumoxiden in Eisenschmelzen
Authors: Steinmetz Eberhard , Andreae Christoph 
Published: December 2016

Die Ausbildung und Beeinflussung von Aluminiumoxiden bei Reoxidation wurden in Laborschmelzen mit einer kombinierten Sauerstoff‐Meß‐ und Dosierzelle untersucht. Die Konzentrationsgrenzen und die Stoffstromdichten, die für die Bildung bestimmter Einschlußformen bestimmend sind, wurden in vordesoxidierten Proben ermittelt. Zusätzlich wurde das Verhalten bei veränderlichen Sauerstoffstromdichten und bei gleichzeitiger Beaufschlagung mit Sauerstoff und reinem Aluminium von gegenüberliegenden Seiten aus untersucht. Aus den generellen Richtungen der Stoffströme darf möglicherweise nicht auf die örtlich aktuellen Stoffströme geschlossen werden, da bestimmte Einschlußformen an zunächst nicht erwarteten Stellen, aber reproduzierbar, auftraten. Grenzflächenaktive Wirkung des in Eisen gelösten Sauerstoffs ist als Ursache nicht auszuschließen.Umbildungen in der Morphologie oder Auflösungen von schon gebildeten Phasen fanden – zumindest unter den hier vorliegenden Versuchsbedingungen – nicht statt, wohl aber Neubildungen an anderen Orten nach der bekannten Abfolge der Einschlußbildung.
Prediction of the creep behaviour of metallic materials under step loading using a simple mechanical model
Authors: Pantelakis Spiros G. , Batsoulas Nikolaos D. , Kermanidis Theodor B. 
Published: December 2016

The creep exposure of metallic parts usually occurs under time‐variable loading conditions. For the prediction of creep behaviour under step loading a simple mechanical model is employed. The model is based on the time dependence of the material structure during creep. Therefore, the characteristic parameters of the model are considered to be functions of time and are correlated with the time dependence of the material structure parameters. For the definition of these functions a structure mechanical model has been employed. The mean internal material resistance has been considered as an appropriate structure parameter. The characteristic parameters of the model are defined in each step loading on the basis of the change of the internal stress derivative.For the verification of the model prediction the numerical results are compared with experimental results of the austenitic steel X 8 CrNiMoNb 16 16 for the orthogonal cyclic stress function.
Model experiments on mass transfer in ladle metallurgy
Authors: Mietz Jürgen , Schneider Stefan , Oeters Franz 
Published: December 2016

Model experiments on mass transfer in gas‐stirred ladles were carried out in reactors of different geometric dimensions. The model system consists of: water, cyclohexan as model slag, iodium as element to be extracted from water into slag phase, and compressed air as stirring gas.The experimental results show that when using an eccentric bottom nozzle, rate constants of mass transfer are always smaller than with centric gas injection. Centric stirring leads to comparatively larger increases of rate constants if a certain gas flow rate is exceeded. Both results can be explained by different emulsification conditions of slag phase.Theoretical calculations of residence times show that mainly the emulsification of small droplets taken along by the recirculation flow is responsible for accelerations of mass transfer in gas‐stirred ladles.
Chemical behaviour of nitrogen in metallurgical slags
Authors: Wenz Heike , Janke Dieter 
Published: December 2016

According to previous experimental work, nitride capacity CN, in opposition to sulfide capacity CS, decreases with increasing optical basicity of metallurgical slags. This tendency is also confirmed by the contradictory behaviour of the free energy changes of oxide‐nitride and oxide‐sulfide transformation reactions as a function of basicity.From the present metal‐slag equilibrium studies, denitrogenation potentials PN = %(N)/{%[N] · %[Al]} were obtained characterizing denitrogenation efficacy of slags at given compositions and temperatures. From these potentials, factors were derived which mark the effects of individual slag components. It was found that these factors feature the same basicity dependence as nitride capacities CN and denitrogenation potentials PN. The factors are increased, e.g., as less basic oxides are increasingly present in the slag phase in the order BaO → SrO → CaO → MgO.
Martensitic high‐nitrogen steels
Authors: Berns Hans 
Published: December 2016

Interstitial nitrogen considerably improves the corrosion resistance of low‐tempered martensitic stainless steels. It may be introduced into the bulk by pressure melting or powder metallurgy and into a surface layer by case hardening. The new high‐nitrogen steels (HNS) are suitable for stainless tools and bearings.High‐tempered HNS are outstanding due to a fine dispersion of stable nitrides, which improve the hot and short time creep strength as well as the toughness. This may be used in hot‐work tooling. Long time testing will have to prove whether HNS offer advantages in fossile power plants.
Solubility of nitrogen in austenitic FeCrMn alloys
Authors: Kunze Joachim , Rothe Ines 
Published: December 2016

The equilibrium solubility of nitrogen in austenitic iron‐chromium, iron‐manganese, and iron‐chromium‐manganese alloys with mass up to 20 % Cr and 18 % Mn was measured in the temperature range 1273 to 1473 K. The following interaction parameters were obtained:

urn:x-wiley:01774832:srin01081:equation:srin01081-math-0001Describing the effect of chromium and/or manganese on the nitrogen solubility by the excess term , the present measurements correspond satisfactorily to those of Hertzmann and Jarl and of Zheng in the system Fe‐Cr‐N, but they differ somewhat from values calculated by means of parameters published by Frisk. For the system Fe‐Mn‐N the present measurements correspond to measurements by Grabke et al. and to values calculated with parameters published by Qiu. Using parameters deduced from the present measurements in the austenitic Fe‐Cr‐Mn‐N system similar nitrogen solubilities were calculated as Zheng had measured, but small deviations were found between the analysis by Qiu and this investigation.
Component specific influences on the fracture behaviour of high speed steels under static loading
Authors: Lippmann Nils , Spies Heinz‐Joachim 
Published: December 2016

This paper presents the first results of a series of investigations into the fracture behaviour of high speed steels with regard to component specific influences. The aim of the investigations was the analysis of the interaction of internal and external notches during the fracture process. Hardened and tempered high speed steel S 6‐5‐2 of various degrees of hot forming, which was produced by electroslag remelting, as well as powder‐metallurgically produced high speed steel ASP 23 were tested to investigate the influence of different carbide sizes and distribution.In‐situ bend tests showed the role of the carbides as fracture initiating defects, which form subcritical cracks as a result of the higher stiffness and lower failure stress at loads smaller than the global failure load of the specimen. The observed fracture process was simulated by FEM using the observations and results of the in‐situ bend tests.The interaction of internal flaws and external notches was proven using notched and coated specimens as well as specimens of various surface roughness. The fracture initiating defect is the largest defect in the loaded volume regardless of whether it is an internal flaw (carbide) or an external notch (surface roughness, surface layer). Information can be derived from the investigations allowing the optimisation of the manufacture of high speed steel tools with regard to their fracture behaviour.
A new creep equation for ferritic and martensitic steels
Authors: Bartsch Herbert 
Published: December 2016

Creep rupture tests lasting 100 000 h at temperatures between 500 and 650°C were conducted on X22CrMoV12‐1 rods. An equation has been derived from the measured creep data for the primary and the beginning of the secondary creep range of the following form

urn:x-wiley:01774832:srin01142:equation:srin01142-math-0001A new element in the equation is the description for the dependency on stress f(σ) which was obtained from the stress dependency in the Norton equation

urn:x-wiley:01774832:srin01142:equation:srin01142-math-0002The new equation allows the description of the creep behaviour up to a strain of 0.5 %. Using the equation, the corresponding stress can be calculated to an accuracy of ±10 % from the strain limits determined in relation to time during creep rupture tests (above 0.1 % strain).
Material property database for heat treatment simulation of tool materials
Authors: Thuvander Anders , Blom Roland , Jin Lai‐Zhe , Sandström Rolf 
Published: December 2016

A materials data base has been set up with mechanical, thermophysical and transformation properties of tool and creep resistant steels. In particular powder metallurgical materials have been covered. The intended use of the data is for numerical simulation of heat treatment with focus on computation of residual stresses and distortion in Compound materials (macro composites).The main body of the data was generated in new experiments. In this paper data for the powder metallurgical high speed steel ASP 2060 will be presented. The material properties determined include thermophysical data such as thermal conductivity and specific heat, mechanical data such as yield strength and work hardening rate, and thermal expansion data. Most data were determined at different temperatures and after heat treatments to different microstructures. Additional data added to the database include literature data for elastic properties and transformation induced plasticity.Quenching of a Compound ring consisting of an inner high speed steel and an outer tool steel was simulated numerically using two codes, DistSIMR and Trast7. With the help of a database interface input data adjusted to the formats of the two codes were generated. The results of the simulations showed good agreement between the two models both for the computed residual stresses and distortions, which confirms the reliability of the results.
Microstructural stability of the martensitic steel X20CrMoV12‐1 after 130000 h of service at 530°C
Authors: Straub Stefan , Blum Wolfgang , Röttger Dietmar , Polcik Peter , Eifler Dietmar , Borbély András , Ungár Tamás 
Published: December 2016

The microstructural changes in a tube section of X20CrMoV12‐1 due to service are investigated. The investigation was carried out by combining mechanical tests, finite element calculations and mainly quantitative characterisation of the microstructure by electron microscopy.The tensile and fatigue tests at room temperature did not show differences between the tube section and the initial State of another melt. At the approximate service temperature the deformation resistance of the service exposed material is slightly lower. The finite element calculations indicate no plastic deformation. The quantitative characterisation of the microstructure shows that the dislocation structure does not differ from the initial State of other melts. On the other hand the carbide structure grows with time at temperatures prevailing during service. The coarsening of the carbide structure may be the reason for a lower high temperature deformation resistance of the material of the tube section. The microstructural results indicate that the tube section was not influenced by plastic deformation during service.
Denitrogenation of steel melts with oxygen and sulphur by injection of argon under reduced pressure
Authors: Thoms Andreas , Tu Shiwei , Janke Dieter 
Published: December 2016

Denitrogenation of steel melts with oxygen and sulphur was studied under reduced pressure by injection of argon. The rate of nitrogen desorption was found to obey a reaction of second order. The macrokinetic rate increases with increasing Ar flowrate until bubble coalescence occurs in the melts. The effects of sulphur and oxygen on nitrogen desorption were evaluated from the experimental data.The dimensionless rate constant for nitrogen is described by . A reasonable agreement was obtained in comparison with the results of other investigators.
Thermodynamic assessment of the Al deoxidation reaction in liquid iron
Authors: Seo Jeong‐Do , Kim Seon‐Hyo , Lee Kwang‐Ro 
Published: December 2016

The deoxidation reaction of aluminum in liquid iron has been investigated thermodynamically using Al2O3 crucible at 1873 K under Ar atmosphere as a fundamental study for the accurate control of inclusions in the ladle refining process. In addition to the equilibrium constant log KA1 for the aluminum deoxidation reaction, the first‐order and second‐order interaction parameters between aluminum and oxygen were experimentally determined in the concentration range of aluminum up to 1 %. The temperature dependence of the equilibrium constant and the first‐order interaction parameter eA1 was also obtained: log KA1 = 12.32 ‐ 47400/T, eA1 = 15.57 ‐ 36500/T.The equilibrium relation between aluminum and oxygen contents in the aluminum deoxidized iron by applying interaction parameters and the equilibrium constant determined in this work satisfies fairly well the equilibrium data over the whole concentration range of aluminum considered.
Parameters affecting manganese oxidation in top blown basic oxygen converter
Authors: Eissa Mamdouh 
Published: December 2016

The data obtained from 84 heats carried out in a 90‐t top blown basic oxygen converter were used to study the effects of slag composition and temperature on the activity coefficient and activity of manganous oxide in the slag as well as on the manganate capacity and the manganese distribution between slag and metal. In addition, the dependence of manganese activity in the metal on the concentration of maganese and temperature was also investigated.The present study carried out in wide ranges of temperature, 1350–1690°C, and slag basicity expressed as (CaO)/(SiO2), 1.4–10.6, clarifies the dependence of MnO activity coefficient mainly on temperature. The activity coefficient of MnO increases by decreasing the temperature. On the other hand, activity of MnO increases by increasing MnO concentration and temperature. Both activity coefficient and activity of MnO in the slag slightly increase by increasing the slag basicity. At constant temperature, the activity of Mn in the molten metal varies linearly with Mn concentration and tends also to increase with increasing temperature at constant Mn concentration. The increase in manganese activity by increasing Mn concentration is much steeper at high temperatures. The manganate capacity as well as manganese distribution ratio decrease with increasing temperature at constant basicity and tend also to slightly decrease with increasing slag basicity at constant temperature. Equations describing the parameters affecting activity coefficient and activity of manganous oxide in the slag, manganese activity in the metal, manganate capacity and manganese distribution ratio have been derived.
UV/VIS‐spectroscopy of liquid slags
Authors: Okretic Stefano , Nowack Norbert 
Published: December 2016

UV/VIS‐spectroscopical methods have been applied to investigate the absorption behaviour of CaO‐Al2O3‐SiO2‐slags in a wide temperature range from 20 to 1655°C. The observations reveal a strong temperature dependence of the absorption bands, which can be explained by means of a newly developed theoretical model. The model also correlates the observed long‐frequency UV cutoff‐wavelength with the optical basicity. The definition of the optical basicity has been corrected for higher temperatures, since there are remarkable deviations between the solid and the liquid state, which have not been taken in consideration yet.Further investigations on a CaO‐Al2O3‐slag containing CaF2 at 1500°C show that no Fe3+… F‐complexes like Fe3+(F−)4 or Fe3+(F−)6 are formed. F− reacts with Al3+ forming Al‐O‐F‐complexes. The F−‐ions displace the O2‐‐ions from the Al3+. This causes the basicity to increase.
Investigation into TRIP steels won steel research Best Paper Award 1999
Authors: Garbracht Kerstin 
Published: December 2016

Research results are commonly circulated on the occasion of congresses or by publication in technical journals. steel research, the scientific journal edited by the Verein Deutscher Eisenhüttenleute, VDEh ‐ The German Iron and Steel Institute, and the Max‐Planck‐Institut für Eisenforschung, MPI, presents the latest results of fundamental research in the fields of process metallurgy, metal working and materials science as far as the material steel is concerned. Formerly well‐known as „Archiv für das Eisenhüttenwesen“, steel research looks back on 70 years of experience in worldwide exchange of technological basics. In 1995, the editors decided to offer a Best Paper Award with 1.000 US‐$ purse and a pretty diploma.This year, it was for the fifth time that authors have been awarded with the steel research Best Paper Award. The Editorial Board has chosen a contribution to TRIP steels from the papers published in the 1999 annual volume.
Thermodynamic behaviour of Cu in molten Fe‐C‐S alloys at high temperatures
Authors: Huh Ki Haeng , Min Dong Joon 
Published: December 2016

The activity of Cu in molten Fe‐C‐S alloys at high temperatures was measured by a thermochemical equilibration technique. The effects of the contents of Cu, C, and S in the molten alloy as well as temperature on the activity coefficient of Cu in pure and carbon‐saturated iron were determined by measuring the distribution ratio of Cu between molten silver and Fe‐C‐S alloy melts. In molten pure iron and carbon‐saturated iron, the activity coefficient of Cu under infinite dilution, was measured as 11.0 and 28.5, respectively, at 1823K. The interaction parameters between Cu and Cu, S, C in the molten iron at 1823K were estimated: . The dependence of in molten Fe‐C alloy on temperature was determined as follows:pure iron: , carbon‐saturated iron: .Combining the effects of temperature and those of alloying components, the activity coefficient of Cu in the molten Fe‐C‐S alloy could be estimated as follows: .
Relation between steel/slag interfacial tension and the sulphur absorption rate in dependence of the Si and Mo concentration
Authors: Wosch Erwin A.T. , El‐Geassy Abdel Hady A. , Gammal Tarek El 
Published: December 2016

The relation between the interfacial tension at the steel/slag interface and the sulphur transport through the phase boundary has been investigated. The experiments have been carried out at 1550°C. The steel/slag system consisted of Armco iron in combination with a synthetic slag containing 40% CaO, 40% SiO2 and 20% Al2O3. The controlled change of the interfacial tension was performed by additional alloying of the surface active element silicon and surface inactive molybdenum.The different influences of silicon and molybdenum on interfacial tension are directly reflected by the sulphur transport rate. Higher interfacial tensions generally cause a lower sulphur transport rate. A linear relationship was only obtained in presence of silicon.