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The trajectories of gas/powder side injection into a metallurgical vessel are simulated by water model experiments and theoretical computation. The result shows that the momentum of powder increase the trajectory of the jet remarkably. Both computational and experimental data agree with each other in case of gas injection, and the powder velocity is presumed to be around the half of the gas velocity, deducing from the powder trajectories When the position of the side blowing lance tip is feed, 30˚ downward injection (among 0˚, 30˚, 45˚, 60˚) has the maximum horizontal penetration distance. However, when the position of the lance is movable up and down along the vessel wall, the trajectory arc lengthes are not affected very much by the injection angle. Therefore, the optimum angle and position of the injection should be designed in consideration of operating condition.

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In this second part of two articles dealing with the orientation determination of the FCC structure using non-parallel {111} traces, a method of calculation is given for the determination of the elation of grains, defined by the Euler angles of the orientations of the grains before and after the rotation. In the calculation of these Euler angles, two equally plausible solutions result in general. This ambiguity is due to the inherent existence of the mirror-image in the determination of the FCC crystal orientation using non-parallel {111} traces. In cases where rotation is by single slip deformation, however, this state of double solutions may be overcome so that the rotation is determined unambiguously.

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The characteristics of high Cr-Mo-V alloy steel ion nitrided at 450℃, 500℃ and 550℃ was investigated with two types of specimens; one tempered at 650℃, the other tempered at 650℃ and stress relief annealed at 610℃. The tempered and stress relief annealed sample had slightly greater hardness and bettor wear resistance than the only tempered specimen. The maximum hardness and wear resistance can be obtained in both specimens when ion-nitrided at 500℃. Surface hardness is due to dispersion of chromium nitrides formed on the surface and the hardness decreased by coarsening of chromium nitrides as nitriding time increased. The hardness from the surface into the core increased as the nitrogen diffused inside the matrix and formed the nitriding layer. The relative wear resistance to the slider SKH 9 having greater hardness than the nitrified steel shows better compared with the slider SM 15C having less hardness than the nitrided steel.

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The role of Si on the coarsening behaviors of complex carbide particles precipitated in Cr and Cr-Si steels has been investigated using various quantitative metallographic techniques after spheroidizing over the holding time range 300 to 1800 hours at three different temperatures 650, 680 and 710℃. Most of M₃C type complex carbides precipitated in Cr-Si steel are shown to form along grain boundaries and their average particle sizes appear to be smaller in finer ferrite grains, as compared to those in Cr steel. The value for the slope of each straight line obtained from the relation between the log of average particle size find spheroidizing time is approximately 1/3, which is in agreement with diffusion-controlled growth mechanism. The addition of Si to Cr steel does not change the mode of growth equation for M₃C type complex carbide precipitates Activation energes of 195 KJ mol^(-1) for Cr steel and 227 KJ mol^(-1) for Cr-Si steel are found to give rise to the interdiffusion mechanism of Fe, C, Cr and Si involved in each steel. The experimentally determied particle size distributions approach the steady-state distribution curve as spheroidizing treatment proceeds. The shape of curves, however, shows 3 tendency that the range of particle size distribution is wide with a lowered height of the distribution curve.

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In order to study a relation between microstructures and magnetic properties in Alnico 5, Fe-24Co-14Ni-8Al-3Cu alloy was prepared by induction melting, and then optimum heat treatment procedures and microstructures of this alloy were investigated systematically. In Alnico 5, the cooling rate(c) in a magnetic field from 900℃ to 600℃ and the optimum aging time(t) at 600℃ have a relation of log(t)=0.417 log(c) + 0.884. However, the final magnetic properties are highly dependent on the cooling rate. Spinodally decomposed structures of this alloy show that the faster the cooling rate, the smaller the size of the FeCo-rich precipitates and the larger the aspect ratio. Length of the long axis of the FeCo-rich precipitates at a given cooling rate is not uniform due to the interconnection of sub sequent precipitates by magnetic field effect, and this tendency seems to be stronger when the cooling rate is slower. But the length of the short axis of the precipitates is almost same at a given cooling rate. The length of the short axis (ℓ) and cooling rate (c) in magnetic field have a relation of log (ℓ)=2.385-0.317 log(c) Optimum solution treatment temperature of the low temperature solution treatment method is 860℃. It is concluded that the low temperature solution treatment method is more desirable than the high temperature solution treatment method in improving the hard magnetic properties

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In order to find out the reaction processes and a series of morphology for the titanium nitride powders obtained from the vapor phase reaction of TiC1₄ and NH₃, experiments have been carried out in the temperature range between 200℃ and 1200℃ and under the pressure of atmosphere and 4.9 KPa. The reaction products and thermally decomposed powders obtained at various temperatures under the pressure of atmosphere and 4.9 KPa have been investigated by means of X-ray diffraction, TGA and electron microscopy. In the vapor phase reaction, TiNCl started forming at about 350℃, and TiN did at about 500℃. On the other hard, in the thermal decomposition reaction of the products obtained at about 200℃, TiN started forming at about 450℃ either under the ammonia or the argon gas flow. Under atmospheric pressure the titanium powder of approximate particle size 0.05㎛ was obtained at 1200℃ from the vapor phase reaction, whereas, 0.02㎛ or less titanium nitride powder was obtained at the same temperature under the pressure of 4.9 KPa.

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In this study, processing conditions which are possible to obtain Fe_(80)B_(l2)Si_8 amorphous alloy ribbons of good quality were investigated. And also, the effects of theme conditions on the physical and magnetic properties of Fe_(80)B_(l2)Si_8 amorphous ribbons were studied. The optimum processing conditions of Fe_(80)B_(l2)Si_8 amorphous alloy ribbons were the melt temperature of 1230-1380℃ and the roll rotating speed of 2000-4000 rpm. Ribbon thickness and the air pocket size, which is ribbon surface defect, decreased with increasing of the roll rotating speed. The coersive force (H_c) varied with the roll rotating speed and melt temperature. That is, H_c decreased with increasing of the roll rotating speed and increased with increasing of melt temperature. It may be presumed that the reduction of H_c with increasing of the roll rotating speed is attributed to pinning phenomena due to the interaction between domain wall and stress around surface air pockets of ribbons.

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In a dilute ternary stolid solution of alpha iron which contains a substitutional solute M and an interstitial solute I, the equilibrium amount of substitutional-interstitial dipoles M-I at a temperature T is given by the following equation: x/y=[6θ_M/(1-θ_M)]·exp[-(ε¹-ε＾0)/kT] (1) where x is the molar fraction of solute I combined with solute M to form M-I dipoles, y is the molar fraction of solute I existing as single atoms, θ_M is the molar fraction of substitutional solute M, (θ¹_ε＾0) is the binding energy between M and I, and k is the Boltzmann constant. The binding energy of carbon with manganese is -0.27 eV and that of carbon with chromium is-0.3 eV. In a case of aluminium-killed low-carbon steel, the solubility of total carbon (x + y) in the alpha-iron phase is log_(10) [100(x+y)]=-(3300/T)+f where f= 2.27 for θ_(Mn) = 0.002 and f= 2.34 for θ_(Mn) = 0.004. (2) Substitutionl-interstitial dipoles are supposoed to inhibit the motion of dislocations for recrystallization in cold-rolled steels. The presence of Mn-C or Cr-C dipoles have a marked effect on the recrystallization texture of low-carbon sheet steels. The effect is more pronounced in the case of Cr-C dipoles than in the case of Mn-C dipoles. The amount of substitutional-interstitial dipoles which exist just before the commencement of primary recrystallization is important for the control of the recrystallization texture in low-carbon sheet steels. Although our knowledge of substitutional-interstitial dipoles is still unsatisfactory, I feel we are approaching to a quantitative treatment of the effects of alloying elements on the recrystallization texture of sheet steels.

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