Abstract: The hydrogeological conditions in Xishimen iron mine, which is a mineral deposit filled with karst weter, have been deeply expounded. On the basis of the above expounding, the finite element technique for the three-dimensional flow has been applied to solve she hydrogeological parameters of the mining region and to predict the mine inflow of four levels. These research results may be used as the scientific bases for design of the mine drainage. So far, there are few examples of solving hydrogeological problems with the finite element method for the three-dimensional flow. This research may be one of valuable explorations.
Abstract: On the basis of the previous experimental results on low silicon iron, the sources of silicon in the hot metal have been studied by means of the dropping zone method. It is concluded that silica in the coke ash is the predominant source of silicon of the pig iron for steelmaking, and about 70% silicon in the hot metal is from coke ash tinder the experimental conditions.
Abstract: The effect of slags on the oxygen probes with ZrO2 (MgO) solid electrolyte tube was studied. The attack of pure liquid FexO on the ZrO2 (MgO) tube was sensitive, and it became intenser as the temperature increased. The attack of basic complex slags on the ZrO2 (MgO) tube was slighter than that of pure liquid FexO, and the attack phenomenon was not marked within 30 min. The ZrO2(MgO) tube reacted with slag to form calcium zirconic acid on the interface of the tube and the slag, which caused the achieving equilibrium time of the cell EMF to prolong and even to be failure.
Abstract: This paper introduces some results of ESR cast iron based on predecessor's work, in addition, viscosity, conductivity and melting point of slag CaF2 50%, CaO 30%, Al2O3 10%, MgO 5%, SiO2 5%, have been measured and discussed. Experimental results based on many heats show that this slag is suitable for ESR cast iron.
Abstract: One dimensional unsteady problem with 1st kind of boundary condition was solved by using the order of magnitude analysis and theory of analogy. The similarity of heat layer to boundary layer was analysed from five aspects.
Abstract: A cyclic annealing process of phosphorus containing low manganese steels plates in bell-type furnace, being aimed at dual phase microstructures, is studied. The influence of phosphorous on microstructures and mechanical properties of cyclicly annealed steel plates is investigated also, which provides good references for the production of P containing steel plate. The experimental results show that the steel plates containing -2% Mn and (0.1-0.13%) P, which are treated under a cyclic annealing process at 680℃ for 8h follwed by 730℃ for 4h, then furnace cooled to 400℃ and air cooled below 400℃ can meet the mechanical property requirement of T.S. L-540MPa, El.>27% and good drawing quality.
Abstract: The hydrogen embrittlement (HE) sensitivity and the HE fracture characteristics of cold drawn 05Si2 martensite-ferrite (F + M) dual-phase steel were investigated. It's found that, (a) HE sensitility first increases with the area reduction by cold drawing and then turns to decreases; (b) HE of ferrite matrix plays an important role in the HE fracture.
Abstract: Use SEM, white dot precipipitations are found on the surface of rapid solidification powder of maraging steel after 3h aging at 480℃. The precipitations mainly distribute between the solidification dendrite arms on the surface, but none in the powders. The precipitations are the compound of Ti by using energy spectrum and wave spectrum analysis. The aging hardness of rapid solidification powders is much higher than that of solid quenching samples.
Abstract: The extensive investigations on the flow fields with k-ε mathematical model of turbulence and water model are presented. A quite different flow pattern from ordinary caster was found because of mild curvature of mold and strong jet from enclosed nozzle. The typical difference is the unsymmetry of flow whose recirculation zone on wheel side is larger than belt side and extends as long as 4 times the mold width. Another feature is that maximum speeds near walls are in recirculation zones and their values are 2.52 (wheel side) and 2 (belt side) times casting speed respectively.
Abstract: A new algorithm SSTMSD for finding symbolic determinants——state space tree method for determinants is presented by applying LIFO branch-and-bound search technique and the concept of state space tree (it is the development and improvement of Minty algorithm). Based on it and by applying the concept of modified graphs, a new algorithm SSTMSF for finding symbolic system functions-state space tree method for system functions is proposed. As compared with the current conventional methods (e. g. signal flow graph method and directed tree method, etc.), SSTMSF has the following two advantages:(1) Its computing efficiency is higher and its resulted expressions are shorter. (2) The denominator (determinant) and numerator (cofactor) of a symbolic system function can be separately found by repeatedly call the same one procedure SSTMSD.
Abstract: By using X-ray phase analysis method, the structure and quantity change of carbides of power plant boiler steel 12Cr2MoWVTiB (Steel 102) during service were determined. The quantity of carbide MC remained basically unchanged during service. The M23C6 and M6C contents increased during the first stage of service, and then gradually grew stable after 8×104 h of service.
Abstract: A two-dimensional finite length circular ring mathematical model during the cooling, heat preservation and heating process of slab ingots has been developed. The model can be used to study the heat transfer of a entire slab ingots. The calculated results from this model are in good agreement with the actual measurements, and these indicate that the model is valid.
Abstract: By employing the principle of laser reflecting scattering from the surface of the work piece and the laser scanning technique allied with compu-tered data collection, A/D transition and calibration curve fitting, the instrument can measure the surface roughness automatically. The resolution and repro-ducibility of the roughness measurement are 0.001μm and 0.006μm respectively.
Abstract: The atmospheric corrosion resistance of 08CuPVRE and 08CuP weathering steels were investigated by electrochemical methods of AC impedance and linear polarization etc. The corrosion rates were determinated by weight measurements. The results obtaind by above methods compared with that of steels cor-ten A and A3 steel. The following conclusions have been drawn:copper, phosphorus and rare earth could enhance steel resistance to atmospheric corro sion. Steel 08CuPVRE has good atmospheric corrosion resistance.
Abstract: The approximate solution of the singular integral equation with a negtive index is developed and it gives a general method to develop the solution.
Abstract: The Trace amount of Al within the range of 0.004%~0.020% in the low alloy steel was determined by using a spectrophtometric method. Iron in the sample (25 mg) was reduced by ascorbic acid without separation. The absorptance of red complex of Al with chromazurols in a buffer solution pH 5.0±0.3 was measured at 550μm.
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
