Jia Lv

The Anti-Corrosion Study on Zn-Al-Mg Coated Steel Sheets

Z11A3M, Z6A3M, Z1.6A1.6M, and Z1A1M coating samples were prepared in HDPS by traditional continuous hot dipping method. The anti-corrosion ability of these coatings was determined by SST, polarization curve and electrochemical impedance. The corrosion products were analyzed by XRD. The surface and section microstructures were observed by SEM. The results showed, the corrosion resistance of 4 kinds of Zn-Al-Mg coated steel is 4 times as galvanized steel. The Zn-Al-Mg coated steel sheets can be self-cured. MgZn2 and eutectic could be found in all ZAM coating. Zn/Al/Zn2Mg eutectic can be found in all 4 kind of coatings. The reason for superior corrosion resistance of Zn-Al-Mg coated steel is the decomposition reaction of Zn5(OH)8Cl2 which is retained by Mg. Thus the O2 diffusing rate is lowered down. Mg acts as PH buffer and the Zn dissolving rate can be reduced. According the results, the application of Zn-Al-Mg coated steel sheets is forecasted.

Study on paper's basis weight measurement method by double monochromatic light sources

Given monochromatic infrared LED (light emitting diode) device best modulation current, frequency, distance to reach its maximum output power and improve the measuring accuracy of quantifier. Design a wavelength of 2.12 μm, 1.89 μm monochromatic infrared emissions and detection optical path, two monochromatic infrared lights which the photo source sends out after transmits the analyte across the same point to achieve the same point detection and improve the accuracy of the measurement. After the paper samples basis weight have carried out nondestructive testing, which was improved from the aspects of structure. By using the light source, halogen tungsten lamp, filter wheel, electrical equipment can be saved, and it can simplify the measuring system. The experimental results show that when measuring the thickness of the paper in the range, the relative error is within 1%.

Experimental Study for Ultra High Strength Strapping Flat Steel

Ultra high strength strapping flat steel is used in packaging for papermaking, tobacco, compressed cotton and wool. At present, there is only one company can produce it by Lead bath quenching line. In this paper, the feasibility to produce new ultra high strength strapping flat steel of which tensional strength is 1350 MPa and elongation is 12% by continuous annealing process was investigated. The experiment result of steelmaking, hot rolling, pickling, cold rolling and continues heat treatment showed, the steel could be got using new chemical composition. The microstructure and X-ray diffraction spectrum of the steel showed, the steel was strengthened and toughened by martensite and retained austenite. The effect of continues heat treatment on microstructure and mechanical properties was discussed.

Analytical Studies on the Rate Equations Including Background Losses Applicable to Fiber Lasers Doped with Three-Energy-Level Ions

This paper derived an analytical expression of the threshold pump power of the fiber laser with three-energy level do pants from the rate equations including loss coefficients of the pump and laser radiations. And based on the implicit expression specifying the pump variation along the fiber and expressions of the position dependent population densities on the three energy levels in terms of the pump variation, the rate equations describing the threshold pumped fiber lasers was analytically solved out. The results show that the longer fiber length leads to the greater influence of the pump loss coefficient. Those results obtained in this paper are applicable to both single- and double-clad fiber lasers.

The Effect of Composition and Microstructure on Corrosion Behavior in SST of Zn-Al-Mg Galvanized Steel Sheet

Z11A3M, Z6A3M, Z1.6A1.6M, Z1A1M and Z1M coating samples were prepared in HDPS by traditional continuous hot dipping method. The microstructure, element distribution and phase was analyzed by SEM, EPMA and XRD. The corrosion resistance was checked in SST. The result was, MgZn2 and eutectic could be found in all ZAM coating. The ZAM coatings showed excellent corrosion resistance in SST than GI. The corrosion resistance was 4.1 to 11 times of GI. There was no strong relativity between alloy composition and corrosion resistance due to Mg enrichment on the surface of coating. Edge-unsealed ZAM samples showed good corrosion resistance than edge-sealed sample.

The Effect of Annealing Temperature on the Properties and Second-Phase Particles of 0.4mm Galvanized Ti-IF Steel

A series of simulated continuum annealing experiments were done on 0.4mm Ti-IF by Gleeble-3800 thermal simulation machine at 700, 730, 760, 790, 820 and 850 degree. The optical microstructures of the specimens were characterized. Transmission electron microscopy analysis was carried out to investigate the second phase particles shape, size and distribution. The mechanical properties of the specimens were measured. The results showed that the yield strength and the tension strength of the steel decreased when the annealing temperature increased, the elongation increased when the annealing temperature increased, expect a maximum elongation value at 760 degree. Based on the microstructure and the second phase, the reason why there was a maximum value was discussed.

A Study on the Earth Pressure of Top Culvert of High Embankment

Based on the extensive research and analysis of actual condition of top culvert of high embankment, a calculation theory for the earth pressure of top culvert was presented. The theory could optimize the structure design for culverts, and reduce the waste of resource. First, based on the simplified assumption of the stress of soil on the top culvert and the analysis of single unit of the load on the top culvert, the calculation formula of earth pressure on different position of top culvert was presented by theoretical derivation. Then, to verified the results by using scaled test model and ABAQUS finite element software. Through the comparison with the traditional calculation theory and finite element simulation, we could prove that the calculation theory is more tallies with the actual situation of the earth pressure on the top culvert.

Laser alignment measurement model with double beam

Double LD-Double PSD schedule.employ a symmetric structure and there are a laser and a PSD receiver on each axis. The Double LD-Double PSD is used, and the rectangular coordinate system is set up by use of the relationship of arbitrary two points coordinates, and then the parameter formula is deduced by the knowledge of solid geometry. Using the data acquisition system and the data processing model of laser alignment meter with double laser beam and two detector , basing on the installation parameter of the computer, we can have the state parameter between the two shafts by more complicated calculation and correction. The correcting data of the four under chassis of the adjusted apparatus moving on the level and the vertical plane can be calculated using the computer. This will instruct us to move the apparatus to align the shafts.

Solving Rate Equations Including Background Losses Applicable to Threshold Pumped Fiber Lasers with Three-Energy-Level Dopants

An analytical expression of the threshold pump power of the fiber laser with three-energy-level dopants has been obtained from rate equations including loss coefficients of the pump and laser radiations. And the rate equations describing the threshold pumped fiber lasers have been analytically solved following the derivation of the implicit expression specifying the pump variation along the fiber and expressions of the position dependent population densities on the three energy levels in terms of the pump variation.

Textural Spectral Characteristics of the Cholesteric Liquid Crystal

For the cholesteric liquid crystal (hereinafter short for Ch-LC) possesses special optical properties, it has specific applications in the area of liquid crystal displays and optoelectronic devices. Specimens of Ch-LCs in planar and focal conic texture stably are prepared. The photographs of textures are shot by polarizing microscope and transmittance spectrums of different textures are measured by spectrophotometer. It is found that the specimen in focal conic texture with large crystal domains has the well transmission property. The experiment has an important significance for applications of liquid crystals.