Abstract: Based on the analysis of fragment flowing regularity in the drawing process, a concept of flowing zone as well as consolidating zone has been presented. Ore flagment mechanical model and relevant formulas of drawing dynamics also has been established. According to variation principles the motion locus of flagment as well as the shape of flowing zone has been determined. A new developement in the drawing dynamics process has been realized thecretically.
Abstract: In order to explain the influence of content of MnO in slagon the content of silicon in the pig iron, the behaviour of the reaction﹝Si﹞ + 2(MnO)=2﹝Mr﹞ + SiO2 to make the silicon out of metal and the limiting factors of this reaction are pointed out, based on the variety regularity in the practical data of blast furnace, the data of laboratorial research and of the reference of our country and other countries.
Abstract: The quantity, morphology,composition and dimensional distribution of inclusions for the continuous casting strand of Ti-stabilized stainless steel has been investigated in this paper. The results arc as follows, there arc two kinds of inclusions in this stainless steel. One is the oxide containing Ti、Na, K. The size of oxide are 100-200 μm. The other is TiN cluster. The single phase of TiN is less than 30 μm. And the accumulation of inclusions could be seen both in the surface of inside radius and the centre of slab.
Abstract: The oxygen probe with solid electrolyte was used for the determination of the activities of FexO in basic complex slags, and the error analysis has been done. The activities of FexO show positive deviation from Raoult's law. It is found that the deviation decreases with increasing CaF2·FexO content and the basity of slags, and increases with increasing P2O5 content. Activity of FexO decreases with increasing temperature when the basity (CaO/SiO2) value is greater than 2.1, Iso-activity curves of FexO are drawn on the pseudo-ternary diagram FexO-(SiO2 + P2O5 +Al2O3)-(CaO+ MgO+MnO+CaF2).
Abstract: The influences of content of cerium on the transition of various forms of graphites in casting iron is studied by means of undirectional solidification, optical microscope and scanning electron microscope. The conclusions are that, as the content of cerium is increased gradually, the flake graphite can transformed successively to supercooled graphite, vermicular graphite, intcrdendrile vermicular graphite and sector-like graphite under a constant moving speed of interface between solid and liquid. According to the results of referencc﹝1﹞ the conclusion is drawn that the morphology transition between nodular graphite, vermicular graphite and flake graphite is reversible. Besides, the coupling eulcctic growth between graphite and austcnilc is observed even in a liquid of high content of cerium.
Abstract: Iron-base disk superalloy GH132 is susceptible to LCF notchsensitivity,even it has no stress rupture notch sensitivity at elevated temperature. The creep/fatigue interaction lives to fracture of GH132 for notch and smooth specimens both exist "nose" curves with maximum lives to fracture. In the regime above the "nose" alloy is susceptible to notch sensitivity. Below and near the "nose" regime, lives to fracture of notch specimens are longer than smooth specimens. For turbine disk alloy development is nesessary to raise the strength and to improve the ductility both.
Abstract: In this paper, th mathcmatic model of the asymmetricalcooling heat transfer process of ingots in the teeming-train is presented. This results have been proved by practical example to be used to estimate the errors caused by the symmetrical heat transfer condition assumpations and its availability in the actual production process. In the same time, it can provide to further study thermal state parameters of local positions of ingots.
Abstract: This paper presentsa study on the workspace and the dexterityof general industrial robot with 5 joints. Particularly, it deals with the section in the workspace containing the first axis and the dexterity ol points in the workspace, using the method of geometrical drawing and computer graphics. On the basis ol this tesults, the best work region of the manipulator is gained.
Abstract: With the application of one gate turn- off thyristor (GTO'S)and six thyristors, a new current source inverter has been developed. GTO'S is used to control commutation lime of thvristors in the inverter section. Three capacitors are connected to the AC output terminals to provide commutation and to absorb ovcrvaltage spikes and to reduce harmonics in the output current. A 2-kW induction motor is driven by the inverter. The motor valtage and current waveforms are measured and compared with those obtained when the motor is driven by a conventional current source inverter. Therefore, this new current source inverter is very suitable for AC motor variable speed drive in fans or pumps.
Abstract: This paper introduces a realization method of microprocessor-based control for magnet exciting system of synchronous machines. The automatic measurement of magnetizing of the thyristor excitation, the strong magnet excitation by voltage feedback and the trigger of the thyristor gating circuit of three-phases controlled rectifier bridge are all monitroed by singe-chip microprocessors known as MCS-51 series. This method greatly simplifies the whole system. Experiments show that the method is very reliable.
Abstract: Studied with AES and chemical analyses, the distribution of phosphorus was found to be different between nodular iron and grey iron. Phosphorus atoms segregate at iron/graphite interface in nodular iron, while the interfaces in grey iron are free of phosphorus. Such different behavior of phosphorus between nodular iron and grey iron is opposite to that of sulphur.
Abstract: In this paper using electrochemical method the coatings ofFe-Cr-Ni alloy was prepared. The effect of electrodeposition conditions on forming coatings of 304 stainless steel was discussed. The results indicated that when the content of Cr3+ and Ni2+ in the bath is to a certain ratio, a Fe-Cr-Ni alloy coatings corresponding to the composition 304 stainless steel (18Cr/9Ni) can be obtained at normal atmospheric temperature, lower pH values and proper current.
Abstract: A series of binomial formulae of △G°-T dependence and their diagram for the formation of oxides of Pb、Sn、In、Ga and Ce were given on the basis of calculated results of data from《CData Bank of the Thermodynamic Properties for the Inorganic Substances》. The oxide on the surface of solid metal Sn and Pb-Sn alloys, found by corrosion in atmosphere, dry and heat air or vapor, was defined as SnO2 using XPS. A similar result is obtained for solid Pb. The corrosive layer on the surface of solid Pb was defined as Pb3O4 which was formed by passing of dry and heat air over Pb.
Abstract: In this paper, the synergism in the extraction of Europium(Ⅲ) and Gadolinium (Ⅲ) with the mixed extractants of thenoyltrifluoroacetone (HTTA) and trialkylmethylammonium nitrate (N7402) has been reported. The optimun conditions of the HTTA-extraction, N7402-extraction and,HTTA N7402}-synergistic extraction have been determined. The separation factors of europium and gadolinium in these systems have been determined also. The extractable species of europium (Ⅲ) and gadolinium (Ⅲ) from synergislic extraction are ion-associated pairs and their stabilities exhibit the "nverted ordinal phenomenon". From the method of slope-analysis, the compositions of these two extractable species are probably(R3NCH3)+·﹝Eu (TTA)3NO3﹞- and (R3NCH3) + ·﹝Gd(TTA) 3NO3)-. The mechanism of the synergistic extraction in these two systems has been discussed.
Abstract: The internal friction of hydrogen at low temperature and the annealing effect on it have been studied in iron-nickel based metallic glasses using Bordoni-type apparatus. The result shows that the internal friction of hydrogen at low temperature is snoek-like relaxation and the abnormal modulus defect and the abnormal relaxation strengh have been observed. The model of enhancement of τ-type defect to snoek-like relaxation is proposed to explain the abnormal relaxation strengh.
Abstract: Prof. Chang Yuanda proved Theorem 4 in his well-knownbook "Structure of Finite Groups" (in Chinese) (P.49). and pointed out that the condition that﹝G:NG(H)﹞ is finite was the key of the theorem. In this note, it is shown that the codition can be left out, and a more general theorem has been proved.
Abstract: In this paper the distribution of the friction coefficient is described as an ellipse. The equivalent friction coefficient is presented. The distribution curve and expression are found. According to these, there are two kinds of regions in the oxy plane:one is called slide region, the other is called unslide region.
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
