Abstract: The cause of formation of Jinshan mountain Great Wall mineral water deposit in various aspects, such as geological condition, hydrogeological condition, chemical composition of the mineral water was studied. The isotopes of hydrogen and oxygen (H2, O18, H3) content in the mineral water revealed the source, age, elevation and position of recharge water of the mineral water deposit. The main chemical composition of the mineral water verified the geological structure of groundwater storage and the condition of deep water cycle.
Abstract: In accordance with the coexistence theory of metallic melts structure involving compound formation and Fe-Al phase diagram as well, and by means of regression analysis, the structral units of Fe-Al melt at 1 315℃ and 1 600℃ have been determined. On the basis of these structural units, the calculating models of mass action concentrations have been deduced. The agreement between calculated values of NFe, NAl and measured αFe,αAl respectively is satisfactory.
Abstract: Based on the metallurgical kinetics and the industrial conditions, a formula of decarbonization was obtained, which is suitable for the law carbon range during stainless steel making in 20t combined-blown converter. The numerical sloutions by Runge-Kutta method were approximately in agreemeet with these measured on-site.
Abstract: By means of OPM, SCM, EP and chemical analysis, the role of RE in centrifugal-casting grey cast iron pipes is studied. The results show that the structures are rery course and heterogeneous in glay cast iron pipes for ordinary centrifugal-casting. When a suitable quantity of RE is added into the melt during pouring, both the macro-and microstructures become fine and homo-geneous,and the degree of chemical segregation is also considerably reduced.
Abstract: The effects of natural aging on mechanical properties and micro-structure of cold drawn dual-phase steel wire have been invastigated. It is found that the effect of natural aging for 6 monthe on the mechanical properties and microstructure of dual-phase steel wires is obvously, either of cold drawn or cold-drawn and followed by recovering before natural aging. In the case of cold-drawn, the tensile strength is increased during natural aging, while the ductility is reduced. However, in the case of cold-drawn and followed by recovering, the tensile strength is incresed during natural aging, while the ductility is also increased. The microstructures of steel wire have been observed by means of TEM. The resons of effect of natural aging on the mechanical properties were discussed.
Abstract: A Fe3Al intermetallic compound with high room temperature ductility has been obtained by means of combination of proper alloying addition and hot deformation. The relationship between properties and fractography was investigated. It was found that the fracture model of the alloys became a mired intergranuar-cleavage model while the Fe3Al containing no Cr showed pure cleavage one. The improvement of room ductility can be attributed to the increase of cleavage strength.
Abstract: Dilating operation of mathematical morphology was taken to measure the fractal dimensions of metallic fracture profile. Comparison between the results got from dilation and slit island analysis was made.
Abstract: Conventional microhardness test were employed to characterize the mechanical properties of magnetron sputtered diamond-like carbon thin films of thickness of 0.09-0.56 mirons. It was found that microhardness of magnetron sputtered DLC varies with sputtering parameters in a systematic way and it can be related to the diamond-like properties and the component of SP2 and SP3 structures of the DLC. Analysis from DLC of 0.3073μm which were simu-taneously sputtered onto stainless steel and single crystal silicon substrate at 200W showed that the true hardness of the DLC was ranging between HV 6000-6600, which is close to the hardness of natural diamond. Pronounced indentation size effect (ISE) was observed, and the ISE index of 1.9 for the DLC was obluined.
Abstract: The influence of silicon on the formation and variation of fibrous martensite of low carbon Si-Ma dual-phase steel was studied by quantitative metallography, SEM and TEM. The results show that when superheating degree is given, the thickening rate of the fibrous martensite slows down with the increase of silicon content. In the structure of intermediate quenching specimen, the starting disappearing temperature of the fibrous martensite increases with silicon content of steel.
Abstract: The plane anistropic paramater (rH) of low carbon steel sheet in two stage strain paths was measured using Hill's Criterion,ε1p and ε2p measured from the experiments, a linear relationship was observed. rH is as a simple function of the slope term, which is independent on ε1p.
Abstract: Based on a large number of test results for the V-Ti nodular cast iron gears the relationship between remains deformation σ and static bending strength limit σFlims was obtained. This result further confirms that the static bending strength of gears depends on the ratio of remains deformation to module.
Abstract: A fast polarity correlation algorithm is presented which utilizes the functions of a standard 8-bit microprocessor to handle 8-bit data and to look up a table. The peak of the correlation function is searched by scanning and bisection method. When it is programmed on a Z8671 Single-chip microcomputer clocked at 7.3728MHz, this algorithm allows a maximum sampling frequence of 18.08kHz, and for a measurement window of 127 points with 256 integrated points, only 10ms is required after collecting data to give out the transit time over distance L. Therefore it is possible to make microprocessor-based correlator for real time applications.
Abstract: The behaviour of oxygen in melting copper in the refining process of anodic copper was studied by thermodynamic analysis. The level of impurity and the extent of oxygen in melting copper which must be controlled at end-point of oxidation and reduction were also evaluated by thermodynamics. A high temperature oxygen sensor was used to track the change of oxygen and to direct the refining operation during the test of refining anodic copper. The result of experiment, a smooth surface and high physical quality anodic plate was successfully got from raw copper containing high nickel and sulphur.
Abstract: The equation of negative shift “E0” of pipe/ground potential at connection point, the relation-ship between potential attenuation coefficient “a” and calibration coefficient “r” as well as electric conductivity “g1” of coating are dedueecl by systematic analysis a vast amount of experimental data collected from cathodic protection system of underground pipelines with sacrificial anodes.
Abstract: The pitting mechanism of passive 304 stainless steel monocrystal in pH1.0, 0.25mol/l Na2SO4 solutions containing chlorion has been investigated using a. c. impedance technique. The impedance characteristics in pit initiation and propagation stages have been analysed. It is proposed that an intermediate complex (MOHCI)comc will form in both the two stages. A pitting mechanism model and an equivalent circuit model in pit propagation stage have been propesen, it has no intrinsic difference with that for 304 ss polycrystal.
Abstract: Three methods of waste heat recovery, including technological, energetical and comprehensive method, are studied. The formulae of energy savings of these methods are derived. The practical waste heat recovery method, preheating combustion air by the heat exchanger is also analysed and the effects of type and size of the heat exchanger on fuel utilization coefficient and energy savings of furnace are discussed. The optimum method of designing and selecting heat exchanger is proposed.
Abstract: Reconstructed model technique is successfully applied to measure short fatigue crack length in the testing work. According to elastic-plastic fracture mechanics method, it is put forward an estimated formula for short fatigue crack propagation rate at notch. Using △εp (effective plastic strain range of crack tip) as a controlling parameter, the solution to the normalizing problem of propagation rate of short fatigue crack as well as long fatigue crack at notch for 45# steel 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
