Abstract: Manganese equilibrium between FeO-MnO-MgO-SiO2 slags and molten iron has been analyzed by use of the coexistence theory of slag structure. It is shown that $K{'_{{\rm{Mn}}}} = \frac{{{N_{{\rm{MnO}}}}}}{{{N_{{\rm{FeO}}}}[\% Mn]}}$ does not change with basicities, and maintains constant in considerable extent. Calculated [%Mn] by use of the above regularity agree with the measured values. This in turn shows that the deduced calculating model of mass action concentrations for FeO-MnO-MgO-SiO2 slags reflects the characteristics of this slag system.
Abstract: By improving on the FORTRON program of SUMT, the algorithm of minimizing the global free energy of the system (G), which is the nonlinear programming with equality constraints, have solved. The precision of the algorithm is higher than the others. The program suit to PC computers. The main parts improved on the program is that equality constraints must be forced to a specified precision, before the main program converges.
Abstract: By means of a technique of glass encasement on a levitation melting assembly high undercoolings of melt before solidification were obtained for the Nd-Fe-B-Si systems. It is odserved that a transition of growth form from dendritic to cellular occurs as the undercooling is getting higher, and it is a sudden transition, The highest dimensionless undercooling (θ=AT/TL) obtained for the system excesses 0.3, and X-ray diffraction analysis shows the existence of a metastable phese in the soliditied microstructure in this case.
Abstract: An investigate with thermal simulator of Gleeble-1 500 model was worked out. A series of temperature-stresses curves was obtained in which different pre-compressive stress and temperature was applied. The result show: in the temperature range below the phase transformation temperature, the higher the pre-compressive stresses, the lower the tensile stresses after heat and cold. These demonstrate that the residual compressive stresses be able to resist cracking caused by thermal shock.
Abstract: When the manganese content in steel is 1.79%, the as-hot-rolled microstructure consists some pearlite, and there is physical yield plateau in the stress-strain curve. The lower manganese content, the more amount of pearlite, and the longer plateau of physical yield. But when the manganese content is more than 2.09 %, there is no product of non-martensitic transformation. In the microstructure of as-hot-rolled steel, the island field of martensite is composed of several parts. They are dislocated lath martensite area and twinned martensite area respectively.
Abstract: Seven kinds of properties for V-Ti spheroidal graphite cast iron gears have been investigated. The results show that these gears have advantages, such as the endurance limit values σHlim the wear resistant ability, the structural damping rations and reducing the noise etc.
Abstract: Using power circulating type gear tester, 33 pairs 20CrMnMo carburized and quenched gears, having tooth surface hardness HRC62, were tested to investigate the contact fatigue life. The test results were treated by statistical methods and plotted as R-S-N curve. The contact strength limits σHlim were 1 571.6 N/mm2 with reliability 0.99 at 5×107 cystes. By using scanning electron microscope etc., the texture of tooth surface damage were described and the mechanism of failures was investigated.
Abstract: By studying the condition of the uniform energy drive about three meshed non-circle gears, speed ratio functions of the equal speed mechanism in the flying shear and pitch curve functions of non-circle gears were developed. According to the demand of cutting operation, all constant factors in the functions can be calculated by several equations which have been analytically developed. The adjusting method for this mechanism in use has been introduced too.
Abstract: Using camplastometer with high and constant strain rate the flow stress of low carbon nio-birm containing (Nb 0%~0.12%) steels has been investigated. The deformation Temp, are 750°~1150℃, strain rate are 5~80s-1, acount deformation 0.06~0.69. The effects of Niobium content, T, ε and ε on the flow stress of steel were analysised, and a model of flow stress for these steels with precise draft were established. This model can be used for computer control in rolling mill.
Abstract: This article focuses on the analysis of line motion mechanism of two motion clay gun for blast furnace. SUMT optimal design program has been applied to the calculations of design varibles. Croups of design parameters have been provided for blast furnace of different volume. These parameters can be of benefit to the design of clay gun of this type.
Abstract: Four methods of static simulation of hydraulic systems are discussed. The features and appropriate ranges of each method are analysed. A detailed description of an interative method which has been successfully used in the static simulation of a DYBQ-16G type valve are also given.
Abstract: As a 15t top-bottom composite blown converter to some steel work example by common IBM-PC, the computer operation and superintendence for composite blown converter steelmaking are introduced. Simultaneously, self tunning predictor for end point C. T and intelligence operation of additional blown are presented. The program block-scheme and the experimental results are also given.
Abstract: Some features of δ-operator and δ-transform, and the description for discrete time system are reserched. The comparisons of δ-operator with s-operator, of δ-operator with z-operator are performed. Finaly, its application in discrete system simulation and contol system designment are disccused.
Abstract: At the grain boundaries of Al-0.35%Si alloy samples which are treated at high solution treatment temperature followed by uniform cooling, the Si-rich precipitates could be found, and the relative amounts of precipitates increased with the increasing of solution treatment temperature. For the samples which are firstly treated at higher solution temperatures and then treated at lower solution temperature followed by uniform cooling, the amount of precipitates is the maxinum for 25min. For the sample treated for 25min at lower temperature followed by water quench, precipitates which are larger than 1μm could be observed at grain boundaries. The above results show that non-equilibrium segregation of silicon exists at the grain boundary of aluminum.
Abstract: With the experimental data of particle-wall contact frequency and contact time, along with the data of the increasing rate of local convective heat transfer of the gas flow disturbed by particle movement, the previous single-particle model has been improved and the varying local heat transfer coefficients around an immersed horizontal tube have been predicted. The prediction shows good agreement with experimental data.
Abstract: A plastic twist cycle was used to deform CuZnAl alloy. The second half twist cycle (SHTC), contrast to the first half twist cycle (FHTC), is to decrease plastic deformation in the alloy. The phases induced by the plastic deformation of FHTC and the influence of the plastic deformation during SHTC on them were studied by electic resistance method.
Abstract: Given the first row or first column, a pandiagonal magic square of order n for any odd numble n can be constructed simply, if this n is not the integral multiple of 3, and the methods of construction and, strict proof are given.
Monthly, started in 1955 Supervising institution：Ministry of Education Sponsoring Institution：University of Science and Technology Beijing Editorial office：Editorial Department of Chinese Journal of Engineering Publisher：Science Press Chairperson：Ren-shu Yang Editor-in-Chief：Ai-xiang Wu ISSN 2095-9389CN 2095-9389
