Advanced Materials Research Vols. 912-914

Abstract: In this case study, the corrosion failure analysis of high-pressure boiler water-wall tubes in a power plant was investigated by means of the chemical analysis, metallographic examination and scanning electron microscope (SEM) observation. Energy dispersive spectroscopy (EDS) was used to examine the changes of test materials and corrosion products. Based on the failure process of the boiler water-wall tubes and the experimental results, a conclusion was drawn that the failure of water-wall tubes was mainly caused by pitting corrosion. Sulfide and chloride attack was the major cause of localized pitting corrosion on the inner surface, and the outer surface damage was mainly due to the synergism of high temperature sulfide corrosion and flue gas erosion.

Abstract: This paper combined the homogenization method with finite element method. The equivalent mechanical coefficients of the hexagonal aluminum honeycomb core were computed on ABAQUS platform by developing the user subroutine UEXPAN ( ) and Python script file. The results obtained with homogenization method were compared with those obtained with energy method, and it showed the feasibility of homogenization method. Then the effects of thickness-to-length ratio t/l on equivalent mechanical coefficients were taken into account. The results suggested that the equivalent in-plane mechanical parameters vary non-linearly with respect to t/l, while the equivalent out-of-plane mechanical parameters vary linearly with respect to t/l, which will provide reference for optimizing the design of honeycomb core structure.

Abstract: The article aimed at Heat exchanger tube sheet welding experiment and its processing technology programs in a certain enterprise and using the ABAQUS software to proceed simulation on high strength and matrix alloy surfacing transition alloy materials (soft or corrosion protection), which can acquire the temperature and stress field after welding which has been testified the rationality by test result, then determining the suitable heat source model and the welding parameters. At the same time, welding dynamic simulation research result provide adequate theoretical basis for welding test and lay the foundation of optimizing the process and method of surfacing welding. Through the methods of combining theoretical research and experimental verification,under the premise that meet tube sheet properties and strength of materials and related technical requirements,which reduce test cost and time and shorten manufacturing cycle and the methods have guiding significance for establishment of welding procedure.

Abstract: The compression deformation behavior and constitutive relation of Hastelloy X superalloy were investigated in the temperature range of 950 °C to 1150 °C and strain rate range of 0.001 s^-1 to 1 s^-1 on a Gleeble-3500 thermo-simulation machine. The obtained experimental stress-strain data were used to establish strain-dependent constitutive equations. The correlation between the strain-dependent constitutive parameters and flow behavior was analyzed. Comparisons between the experimental and predicted results showed that the developed constitutive equation could be used to simulate numerically the flow stresses of Hastelloy X superalloy at any strains under hot deformation.

Abstract: According to the physical and chemical properties of methanol, fuel was prepared using the methanol and biodiesel. The physical and chemical properties of the blends were investigated, and the combustion process calculation model of 186FA diesel engine was established. The spray characteristics and in-cylinder pressure were calculated of diesel engine fueled with the blend of biodiesel added with 15% methanol at 3000r/min, 5.7kW. The results show that, the spray penetration shortens and the sauter mean diameter reduces when diesel engine fueled with methanol/biodiesel, besides, the maximum cylinder pressure reduces. However, the maximum pressure rise rate increases.

Abstract: Problems of uncertainty for gear steel hardenability control in rolling process, this article will applied improved Quantum-behaved Particle Swarm Optimization algorithm to the uncertainty, using the optimization algorithm to train the neural network by improving quantum groups, build optimized gear steel quenching permeability control neural network model. Simulation results show that this algorithm is an effective solution to the problem of gear steel hardenability predictive control. Keywords: Quantum-behaved Particle Swarm Optimization, gear steel, Hardenability

Abstract: This paper introduce the basic characteristics of LIFEHOPE Military Fire Blanket, as for independent intellectual property rights new material, we use it is heat insulation, heat preservation to save energy for glass furnace etc. Meanwhile we will explain and put forward the meaning of application of LIFEHOPE military fire Blanket for high energy consumption and heavy pollution industry and enterprise.

Abstract: coal pyrolysis and pyrolysis products deep processing is an effective way to achieve efficient use of clean coal , has important theoretical and strategic significance. Through the analysis of the nature of the low-temperature coal tar , coal pyrolysis mechanism from starting , discusses the improved yields five factors of coal tar and coal tar is proposed to improve the yield of several process conditions.

Abstract: As a kind of promising lightweight material, CFRP (Carbon Fiber Reinforcement Polymers) have been widely concerned in automobile industry in last decades. In the present work, series of experiments are conducted to investigate the impact of key process conditions, including the cutting edge geometry, curing process and cutting manner, on the CFRP cross-sections quality by cutting at resin infiltration during implementing the CFRP parts integrated manufacturing processes based on RFI process. For the typical cross-section defect such as the debunching of carbon fiber, chippings of carbon fiber and resin salivation, authors explain why that happens and propose the corresponding suppressing measures. Research results show that, under the existing experimental conditions, the optimal process scheme is to combine the large arc edge with curing before punch returns back and press cutting to obtain the desired CFRP cross-sections.

Abstract: In the paper, Polyurethane (PU)/Epoxy (EP) gradient IPN with different component distribution were prepared , The effect of component distribution variation on tensile property of gradient IPN was studied through change of layer number and gradient factor K. The results indicate that tensile property of gradient IPN increases with increase of layer number n, when gradient factor is below 1, tensile strength of gradient IPN decreases slightly with increase of gradient factor K, While gradient factor K is above 1, tensile strength of gradient IPN undergoes remarkable decline trend. When gradient IPN has rational continuous change extent and gradual change span,It has better tensile property than ordinary IPN.