Mitsutaka Hino

Phase diagram of Fe-Cu-Si ternary system above 1523 K

Fe-Cu-Si ternary alloy phases are commonly formed during melting in a treatment process of domestic waste incineration that is currently being developed. The alloy phases appear in the incineration residue. Experiments were performed to observe phase equilibria in solid Fe+liquid, solid Si+liquid, the compound of FeSi liquid, and so forth, in the range 1523 to 1723 K. Then the phase diagram of Fe-Cu-Si ternary was thermodynamically assessed based on the present experimental results and literature data. It was found that this system has a wide liquid miscibility gap, and this two-liquid region is stable up to about 1900 K. The phase diagram of Fe-Cu-Si system assessed in the present work is much different from an earlier proposed diagram, but is very close to one recently evaluated. From the results obtained, the appropriate condition is discussed for the operation of the melting furnace for ash from municipal solid waste incinerators.

Equilibrium between Dissolved Mn and Ο in Molten High-Manganese Steel

This paper describes the equilibrium relation between dissolved manganese and oxygen in molten high-manganese steel equilibrated with solid MnO. The equilibrium constant of manganese deoxidation was obtained as follows, MnO(s) = Mn + O logK Mn = - 11 900/T+ 5.10 (1823 K < T< 1923 K) The interaction parameter between Mn and O in liquid iron was independent of temperature and is given by e OMn = - 0.037 (mass % Mn < 24, 1823 K< T <1923 K). The interaction parameter formalism with only the first order parameter can represent the variation of the activity coefficient up to 24 mass % Mn in this system, when appropriate correction for a MnO is applied.

Measuring Strains for Hematite Phase in Sinter Ore by Electron Backscattering Diffraction Method

Based on the relationship between quantified blurring degree of Kikuchi bands obtained by an electron backscattering diffraction (EBSD) technique and macroscopic strains measured by a strain gauge, the local compression strain SEBSD in sinter ore has been evaluated under various conditions. There is a good linear relationship between the SEBSD and the strains measured by a strain gauge. The local strain SEBSD evaluated by EBSD patterns can be used as an index of local strains.

Simulation Research on Monomer Agglomeration of Nonmetallic Inclusions in Steel with a Diffusion Limited Aggregation Model

The monomer agglomeration of nonmetallic inclusions was simulated with a diffusion limited aggregation (DLA) model of the fractal theory. The simulation study with a random two-dimensional diffusion was carried out. The results indicate that the DLA model can be used for the simulation of agglomeration behavior of the cluster-type inclusions. The morphology of clusters was observed with SEM and compared with the simulated agglomerates. The modelling procedure of the DLA model is applicable for the agglomeration process. The uncertainty of agglomeration process and the persuasive average agglomerative ratio was analyzed. The factors about the agglomerative ratio with the collision path distance and the size of particles or seed were discussed. The adherence of the nonmetallic inclusions on the dam, the weir and the walls of a tundish, and the absorption of inclusions by stopper or nozzle were also discussed.

Heat content of liquid Fe - Cu - Si alloys formed in the melting treatment process of domestic waste incineration residue

Abstract Some new melting processes for the ash have been developed to solve the problems on increasing volume of ash generated from municipal waste incinerators. The metal phase formed in this melting process generally consists of Fe-Cu-Si-P-C containing a small amount of other heavy metals, but their phase equilibria and physico-chemical properties are unknown. The present work aimed at determining the thermochemical properties of liquid Fe-Cu-Si alloys, which establish the basic system in this melting process. The heat contents of liquid Fe, Fe-Cu and Fe-Cu-Si alloys have been directly measured with a drop calorimeter at mainly 2073 K in the present work. The observed heat content and the enthalpy of mixing of the alloys were assessed by a thermodynamic model. The input energy which should be supplied to melt the metal phase in the new melting treatment process was also discussed.

Refractory Metals Recovery from Industrial Wastes

Refractory metals like Mo and V are alloyed in the special steels like heat-resisting, tool, ship and pipe steels for the improvement of their physical and mechanical properties. Most of refractory metals are refined as by-products in the other metals production processes. Recently, it becomes difficult to open new mines up for the environmental pollution issues, and as the results, it pays attention to recover them from industrial wastes as Mo and V resources instead of new mines development, because these wastes contain higher MoS2 in spent lubricant, MoO3 in oil refining catalysis and V2O5 in an domestic heavy oil combustion ash than the natural minerals containing them. In the present work, it was tried that these refractory metals was recovered as Fe-alloys because more than 80% of refractory metals are used as steel alloying elements and the energy consumption for reduction and production to Fe-alloys are less than that of pure refractory metals production.

High Temperature Oxidation of Liquid Cu-Ti Alloy at 1473K

The kinetics of oxidation of liquid Cu-0.5mass%Ti alloy at 1473K in CO2-CO gas mixture has been investigated by varying the oxygen potential. The pO2 is set to be enough to oxidize Ti in liquid Cu-Ti alloy but not for the oxidation of liquid Cu. Alloy samples were taken with a quartz tube during the experiments and Ti and O contents in the samples were analyzed by inductively coupled plasma method, and infrared absorption method. The phases of the formed titanium oxide layers were consisted of several different titanium oxides and were identified by using EBSD. The oxidation rate was evaluated based on the change of the Ti content in the Cu-Ti melts. The apparent overall oxidation rate is reasonably represented by the parabolic rate law. This oxidation behaviour was well explained based on the multi-layered oxidation theory.

Dissolution Behavior of Elements in Steelmaking Slag Into Seawater

Inorganic minerals such as C., O, N, Si, P, and Fe are necessary for the phytoplankton multiplication. It has been reported by Nakamura et al. [1] that some kinds of phytoplankton can grow quite rapidly once Fe, Si, P and N are supplied into seawater in the adequate proportion. One of the best candidates as a source of such minerals for the phytoplankton multiplication is steelmaking slag because of its cheap cost, sufficient quantity (15 million ton per year in Japan), adequate mineral concentration and its ionic nature (steelmaking slags basically consists of FetO, CaO, SiO2 and P2O5). On the other hand, steelmaking companies are now seeking new technologies to reduce the amount of steelmaking slag and to reuse the slag as new valuable resources [2]. If such technologies are successfully developed, we will be able to regard steelmaking slag as a new ecomaterial.

The Evaluation of Grain Boundary Difussion Coefficient of Iron Ions in Wustite

In this study, the effect of grain boundarry diffusion on the iron nuclei formation during wustite reduction process was investigated. Combined with the measurement of width of the iron nucleation dominant zone from grain boundaries with time and a grain boundary diffusion model, the grain boundary diffusion coefficient of Fe2+ ion in wustite at 1073K has been evaluated.